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ZX Spectrum in the 21st Century?

Dear Visitor!

After 10 years of continuous hard work, this site is become the ultimate source of present ZX Spectrum hardware and software. Also it is the ’bridge’ between amateurs, professionals, sellers, buyers etc. In a sentence: gives a great help to keep the Spectrum alive.

If you want this website to survive and alive, and you have some capacity to help me, please contact me at tarjan(a)uw.hu e-mail address. Thanks in advance!

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Didaktik M 48/128 és Kompakt 48/128/Professional Slovakia Czech Republic
Didaktik Kompakt

Didaktik Skalica company was founded in 1971 in Bratislava in the ex-Czechoslovakian Republic. Primary profile of company are school accessories, but they were tasting also into the computer industry.

Their very first computers -Didaktik Alfa and Beta- weren't ZX Spectrum clones. In fact, the same happened as in most Central-Eastern European ex-socialist countries: at the company realised, can be a far better business to copy the ZX Spectrum with its thousand of games (or even it is reached ten thousand?) rather than developing completely new machines. In that way were born the Didaktik Gama 87, 88 and 89. By the way, these machines were quite popular in Poland too.

Gama-series was soon followed by the still sold Didaktik M (released in 1990, a second version in 1991) and Didaktik Kompakt (1991). In 1992, Didaktik Skalica was stepping to PCs, and passed the rights and manufacturing to Kompakt Services (Kompakt Servis) in the Czech Republic, which is a single person enterprise. The two machines are identical genetically, Kompakt only differs with its built-in 3,5" floppy-drive. Most people say, Kompakt looks better. It is not very conspicuous, that floppy drive is "stuck" later. Looks perfectly neat. A bit reminds us to Atari ST, very contemporary look of early 90's. Both machies have two joystick ports, one of them is Kempston, another is Sinclair compatible, but connectors are non-standard ones (anyway, who would buy the Didaktik joysticks?:). As was usual in the ex-Eastern block, tape connectors are DIN types. Thanks to the Russian ICs, they are not perfectly ZX Spectrum compatible, but closer to the Russian Pentagons in compatibility (see soon). TV and monitor connectors both came as standards also with a Scart-port, as well a parallel interface is integrated too.

Kompakt's built-in 3,5 drive in fact is an ordinary PC unit, which using a factory-developed MDOS operating system and 720K MS-DOS compatible disks. Details will come later.

Kompakt has two big bros. Didaktik Kompakt 128K has the 128K RAM upgrade. Didaktik Kompakt Professional also contains the AY-chip as default with a stereo jack. Following the traditions of Czech and Slovakian tuning conventions, it sounds in ACB stereo mode, which I will described later. M also has a 128K version. The distributor made these enhancements, factory-made 128K machines do not exist. RAM size is said to be 320K expandable - just as in the case of original Spectrums.

Didaktik Gama 192K/256K ME, Nemesis Czech Republic
Didaktik Gama 192K v1C with videoram module

At the end of 2003/beginning of 2004 an enthusiast Czech Spectrumist (CSS Electronics)was reanimated the previously mentioned Didaktik Gama.

The mainboard, which is sold for 1500 Kcs has fairly neat quality and the machine (or more exactly the mainboard) -called Didaktik Gama 192K- is said to be 100% compatible with the 128K ZX Spectrum, just as the original Gama series.

No reason to wonder, because its "basic ingredients" are the same: the Z80A processor working at 3,5MHz and the AY-3-8912 soundchip - this one is tuned-up to ACB stereo - as an usual ex-Czechoslovakian habit. In addition, it has a serial RS-232C port as well a parallel socket. RAM size is total 192K - as you probably guess.

Programs can be loaded from conventional tape magnetofon and TV-set can be plugged to the computer - just as in the nice classic times.

Has three subversions: v1a (never went to sale), v1b and v1c.

Manufacturer also offer(ed) a limited edition called Didaktik Gama 256K Millennium Edition, or Didaktik Gama 256K Nemesis. Biggest innovation of this hardware as you tipped, yes, the 256K RAM.

Pentagon 48/128/256/512/1024/SL/Turbo and compatible interfaces Russia Ukraine Czech Republic Poland

Very first Pentagon machines appeared in 1989 in Moscow (ex-USSR) with 48K RAM, later with integrated Beta-128 disk interface.

In 1991, the first version of 128K Pentagons came out (Pentagon 128K v1) without the AM/YM chip. It was because only this chip does not have Russian analogue, so was quite hard and expensive to obtain. But the sound chip can be installed later with an AY-adapter. This card incorporates the AY/YM chips and the Z80 processor, and must be plugged into the socket of Z80 in the mainboard.

They already have the Centronics compatible Lprint MKIII interface integrated onto the mainboard. These machines were not equipped with the original Sinclair edge connector.

The Pentagon 128K v2+ from the next year was identical with the previous version, but AY/YM chips were installed as standard (v2 does not exist!). This subtype was developed by ATM and micro-ART corporations, which were also developed the soonly mentioned ATM clones. Sadly, it is quite buggy, but rumours said, with some home fixes can be turned into compatible with original Spectrums. One of these moddings were made by 'Z' in 1992.

Nickname of Pentagon v3(+) is Pentagon Solon or Pentagon 1993, and of course it is also incompatible. It was inheriting its name from Solon's company. In that case, engineers were optimised the screen output quality. But everything has its own price....

From the firm briefly: Solon is located in Moscow and was a real universal computing enterprise: spreading programmes, publishing computer literature, making some hardware developments: all of those were fits in their profile. At present, it working as a publishing house under Solon-Press name.

Some sources are speaking about a further development (for example Pentagon v4) but nobody trusted its existence so far. Very probably, this improvement was made in the smaller countries of ex-USSR (for example in Ukraine). At least, in the city of Licichanks in Ukraine saw the light a Pentagon development, which was realised on a 25x40 cm mainboard with more than 100 elements. Due to its size, only can be built into a tower case and was very unstable. Since 2002 no news. Maybe this was the v4 Pentagon, maybe not.

One thing is sure: with increasing the version number, number of ICs on the mainboard became less and less, but still much more than in the original Spectrums. Real Russian design...

Pentagons got their names about the pentagon layout of the conductors ground circuit on the initially introduced 48K mainboard. Following 128K models do not have this layout, but the name remains the same.

They soon became the most widespread models in Russia, thanks to the easy building and expanding - and of course for the relatively cheap price. In addition, all documentations were freely spreadable. Between 1991 and 1996 they became the mainstream machines of Russian computing.

Both individuals and companies manufactured Pentagons. So Pentagons may look very different (convenient home computer like, desktop, mini-tower etc.) and the quality also can vary in very different ranges.

Another key of popularity of the machines were easy expanding and tuning - even the strangest modifications can be done home made.

The "default config" became the Pentagon 128+AY+Beta combination with a cheap stereo tuning, but some special software uses the extreme Pentagon enhancements. For example, the 512x192 pixel screen, the 128-colour mode, the 256K, 512K 1024K or 4096K RAM, and even the 1,7Mbyte HD disk, real time clock, IDE interface etc. They were mostly end user programs (commanders, word processors, painting programs etc.). These machines were mostly owned by programmers and swappers.

Among ancient time Pentagons, the most powerful was Pentagon 512K Turbo. It has 7MHz Z80B or H processor, two floppy drives and Kempston mouse as standard. From standard Pentagons it was quite hard to tune-up, needs much time of home works.

The 512K, 7MHz and 512x192 tuning was made by Vladimir Getmanets (aka V.M.G. or VMG). He was one of the most significant hobby Spectrum developer, who published his works in ZX-Edition-Schemes of V.M.G. between 1997 and 1998.

Instead, the Pentagon 1024K update was chosen by most owners (with one piece SIMM module). By the way, tuning fans can read firstly about Pentagon 1024K enhancement in Born Dead magazine back in 2000 in issue 10.. The creator is Alone Coder (AlCo - Dmitry Bystrov). An another 1 megabyte tuning is done by Prusak (alias Sergey Bagan) from 2002.

The successor's name is Pentagon 1024SL v1.x (2004-.). Easy to guess, it has massive 1024K RAM. This is the development of King of Evil, alias Zhabin Alexei again from Moscow.

It goes only on 3,5MHz, although Lord Vader made a circuit, which allows running it at double speed. It was made on the basis of Pentagon v3, and apostrophed as the successor of the soon detailed KAY. This is proven by the fact, that it is using the bus system of KAY, called Nemo-bus, the motherboard has two such slots.

Pentagon 1024SL V2.x (2006.) runs on 7MHz as default, and top of that it offers two new graphics modes. The Pentagon OverSCan as well the 16C modes. Alongside, 16C games are developed such as Ball Quest, Pang 16C and Season of Sakura 16C. Of course, also begin to appear end user programmes with supporting this mode. Necessary to denote, that 16C games are running on normal, 3,5MHz speed fine'n'smoothly, and that is respectful both from the hardware developers and programmer's side.

Professionals regard this machine the real successor of original Pentagons, not the v1.xs. Standard printer and Kempston mouse port, as well IDE-controller also integrated into the mainboard. Contains three Nemo-bus.

In 2006, Zhabin stopped to manufacture ready-made v1.4 boards, and in 2007 also stopped finished v2.2 ones. Now only can ordered empty mainboards for 800 rubles. The board is made in Zelenograd factory, with today's standard. The developer is attaching a CD-ROM along with the board, which contains mounting and installation instructions as well some games and utilies. Latest commercial version is v2.3.

SL abbreviation comes later with KAY.

On the Pentagon 1024SL v2.666, which was started its life in 2008, the soonly described Z-Controller is integrated, so contains PS/2 keyboard and mouse ports, and SD card and Ethernet interface. Another new developments: real time clock, VGA monitor socket and USB port. In 2009, KOE released a cutted down version, Pentagon 1024SL v2.666 Light Edition, which has fairly more simple design, for example the Ethernet controller is missing.

8, 16 or 32K cache could be obtained for Pentagons, which are works fine with turbo mode too. With this, speed of processor is not 1.4x of the original in turbo mode, but could boast double speed.

Those who had only original Spectrums, the Czech Velesoft is offering some alternatives. The internal Pentagon 512 interface can be built into the ZX Spectrum 128K+2. Later he constructed its cost effective external version for ZX16/48 users with External 128-512K upgrade for ZX16/48K name. The ZX Profi interface also offers Pentagon compatible mode. More informations at the Velesoft section!

The Polish Jarek Adamski also constructed a similar interface, called ZX4MB, which will detailed later too. The Pentevo and Pentevo Light series can be regard as the successors of the original Pentagons.

Pentagon 128 v1 with YM chip
Pentagon 128 v2+
Pentagon 128 v3(+)
Pentagon 1024 v1
Pentagon 1024SL v1.41
Pentagon 1024SL v2.666
Pentagon 512 interface
Profi interface
Pentevo rev C
Pentevo Light

Scorpion ZS 256 Turbo+ Russia Czech Republic
Scorpion ZS 256 Turbo mainboard

Scorpion 256 machines were manufactured in Saint Petersburg by Zonov and Co. Director of the firm is Zonov Sergey and they were producing Scorpions since 1992. The firm was established in the beginning of 1990.

This company already had experience with ZX-cloning by their previous machine called Leningrad. Very similar to Pentagons, did not law protected the machine, it was free to copy the mainboard. Thanks to this situation, different types of Leningrads became one of the first mass clones inline with Pentagons.

But the year 1992 was a significant change in Russia. From that date, different companies take effort not only to reproducing the original ZX Spectrum 128K, but develop more powerful and advanced machines under their brandnames. In that way born the Profi, the ATM-Turbo, as well Scorpion ZS 256 with 256K RAM and initially with 3,5MHz processor and only with 5,25" drives. It uses the simplified version of Beta with only two diskdrives. Generally, only Scorpion was enough successful to get the majority of the market beside Pentagons. Even by the surveys, after the mid 90's, it tooks the leader position from Pentagons.

By passing the time, Scorpions get 7MHz processor as well 3,5" floppy drives. Scorps were not allowed to public copying, but manufacturing, development, sales and service done by only the company. The name of the clone became the name of the company also, which remains the same until nowadays. Just as Pentagons, Scorpions have some different subgenerations ("Normal", Turbo and Turbo+) easily separable from each others by their brown, yellow and green mainboards. Of course, size of the mainboards is also getting smaller, and building quality was improved from generations by generations.

And now, look closer the features of Scorps. First of all, it is perfectly compatible with the original 48K and 128K Speccies, unlike most ex-Soviet clones. The CPU is supporting both 3,5 and 7MHz speeds, switchable from the built-in monitor program or by a hardware switch. Normal/turbo speed is easy to check from a LED. It has 256K RAM, ROM size can vary from 64K to 512K depending on the customer's demands. It has a built-in Service Monitor as standard developed by Andrew Moa (his name in Russian: Andrey Larchenko). Sound is provided by the classic AY-chip. To establish communication, standard Centronics and RS-232C ports as well one or two Nemo-buses are factory fitted. The machine is also available as a ready to use version installed into a mini-tower delivered with keyboard and mouse. Business software and games are also included in the package. Customers can also specify the old fashioned 5,25" floppy drive if they really want. Some tweaked Scorps have 1024K RAM installed on the board.

At present, profile of Scorpion is covering the home and office computing and office accessories since 1997. Unfortunately, Scorpion is not developing the ZX-line anymore, only selling out their remains.

Europeans also do not have to quail, because Velesoft's previously mentioned ZX Profi interface can also upgrade the ZX Spectrum 128K into a Scorpion ZS 256/1024.

KAY 1024, 2006NB, 2010

Russian Federation

KAY 2010

The clone named KAY 1024 produced by Nemo Company, who wants to be his machine as the rival of Scorpion. In the classic Spectrum age, it was the best design counting compatibility, reliability and price.

The name of Nemo covers Vyachieslav Georgievich Skutin, who nicked often as Captain Nemo. In the ancient times, he was the chief editor of ZX-Format magazine. Above that, he is also well-known by his open letters from Abzac magazine, in which he is questioning the worthness of technological development.

Last version of KAY 1024 was introduced in 2001 after KAY 128 and 256. Since 2004, he is activeness on ZX Spectrum. But now go back to machines!

The hearth of the clone is the KAY-1024/3SL/Turbo mainboard. Yes, it has 1024K RAM and supporting the 7MHz turbo mode. In fact, this is the fastest 7MHz clone. Sadly, the turbo mode is unswitchable, so games and demos are not running perfectly. Abbreviation of "3SL" refers to the 3 expansion slots, which are only 2 in practicality: the FDD interface takes one place (Beta Turbo). Anyway, the bus system is his own development of Nemo, called Nemo-bus.

Nemo offered a special Nemo-bus version of IDE controller, which still can be bought and you could order it with a 40Mb hard disk also. In the similar way, customers could specify XTR-modem and General Sound card with Nemo-bus options.

The AY and Dallas chips were sold separately from the board, but offered also by the manufacturer.

The huge 1024K RAM can be used in two ways. Total 1024K or 256K+RAM disk (drive c:). Peripherals, like PC-keyboard, Kempston mouse as well standard Kempston and Sinclair josticks are easy to connect to the system. Has a Centronics port for parallel printers too. Quite interesting fact, Nemo Company never had homepage. The answer is simple: Nemo is hating Internet, as it belongs also to technical developments. He was accessible only through snail mail, making the communication difficult between him and the customers.

Now some words from Nemo-bus, the successor of Sinclair edge connector. Opposite its ancestor, it does not share the resources equally, when more peripherals are attached. The highest priority is the first slot, the second is medium, and the least priority is for the third slot.

Nowadays, all new clones and peripherals are using Nemo-bus in the territory of ex-Soviet Union as standard. Its alternative name is ZX-Bus, but of course totally different from the ZX-bus constructed by the Swedish Sami Vehmaa.

Shortly about the successors. Pentagon 1024SLv1.x was already introduced and Ant-1024 HD will detailed later.

KAY 2006 NB (KAY 2006 North Brigde) is realised by an Altera EPM7064 MAX programmable logical matrix from heroy. Above the standard resolution, it offers three more extras: Multicolor, GigaScreen and 512x192 pixels with 2 colours.

KAY 1024

Sprinter 97, 2000

Russian Federation

Sprinter 2000 in mini-tower

Sprinter is the product of Peters Plus Ltd, which is situated in Saint Petersburg. It is an original architectured Russian computer with ZX Spectrum and clones compatibility.

This company also had a previous clone series, called Peters. In these times, name of the corporation was also Peters. The machines saw the light in four different forms. Peters MC64 was a ZX Spectrum 48K clone with built-in printer port. Peters WS128 is certainly a 128K machine. Peters 256 is based on Scorpion. At last, Contact CPS-128 is a 128K machine based on its original bus system.

Peters Plus suspended manufacturing Sprinter and passed the rights to Ivan Makarchenko, the original developer.

Back in 2004, NedoPC also wanted to buy these rights, but the 10.000 dollars price a bit shocked them. Despite that, they still popularizing these machines and running an “Unofficial Sprinter Support” section on their site.

Sprinter 2000 is already the second generation. Its green coloured mainboard as well finishing quality is helps to distinguish from the earlier Sprinter 97 series, which has yellow-brown colour, and the quality is also quite "Russian". It is not a fortune: all single machines were handmade. Sprinter 97 was introduced on Enlight'96 demoparty in Moscow. Sprinter 2000 has more variants depending on what parts were available.

It is compatible with ZX Spectrum 128, Pentagon 128/512 and Scorpion ZS 256, and also has a special Sprinter mode. Just as the modern clones, this one is also equipped with IDE CD-ROM and winchester controller. It is using the FAT-16 system, so partitions size can be maximum 2Gb (4 partitions x 2 Gb= 8Gb for each hard disks). The processor is a Zilog Z84C15 running at both 3,5 and 21MHz. Pressing F12 key is the most convenient way to select the speed. 21 MHz only theoretically exists, as ULA slows down the speed to 16MHz. The mainboard itself is an AT-type one, ATX-version is not available. Other parameters also recall the classic PC age: ISA-bus, 16 bit stereo sound (of course AY/YM and Covox compatible), 4 Mb RAM and 256K videoRAM (each of them is expandable to 64Mb and 512K). Anyway, the AY-emulation is quite bad. The extra memory usable as RAMdisks lettering from e: to t:. Additional functions are available through extended TR-DOS commands. CGA or RGB monitors, as well Scart-ported TV also suitable for the video. Two non-standard serial ports are equipped in the mainboard - one for the keyboard and one for the mouse. Fortunately, the parallel port is a conventional one, so printers can be connected easily. The Sinclair egde connector is missing from the machine.

Peters Plus was releasing some games (for example Doom, Thunder in the Deep) and some end user software also (Flex Navigator, Audio Player, GFX-Viewer, 2D Studio and so on...). All of these software is free of charge for Sprinter owners (in fact, they are freeware for everyone, but no one else could use them:).

Sprinter mainboards were available through postal order. Sprinter never had massive success. Maybe the first factor was the high price (115 dollars for the mainboard and 170 bucks for the complete configuration with keyboard and mouse). And secondly, very probably it was not dedicated to a mass clone, rather to a toy for the Western-European collectors.

Using the freely released documents created the Sprinter 2003 by Ewgeny7 and loxic. The machine is fully based on the Sprinter 2000, only the video controller placed a bit differently on the PCB. On the zx.pk.ru forum loxic gives detailed informations about the assembling.

Updated: 2010. February 28.

ATM Turbo

ATM Turbo 2+ mainboard (v7.10)

Some dozen of ATM-clone users decided to revitalise the ATM Turbo 2+ clone, which was definitely the most advanced and powerful clone until the Sprinter arrived. This new clone -hopefully- will be ATM Turbo 3. Development is done by the Sprinter's section mentioned NedoPC group located in Moscow. Main purposes of developing to provide easy installation of modern PC peripherals to existing Turbo 2+ architecture (keyboard, mouse hard disk etc.). The group is also working on the operating system of the machine.

But what is ATM exactly? The clone of firm ATM and micro-ART. We cannot call it a simple ZX-clone, much better to name a computer-hybrid, which is ZX Spectrum and CP/M compatible. The two companies were beginning their joint venture in late 80's. ATM started working with production of Pentagon 48 and 128 machines. More exactly they had commercial success with ATM 128 (a Pentagon 128 v2+ computer), as mentioned at Pentagon's paragraphs. As Pentagons were not very widespread at this time, seemed a good business to introduce a new clone.

ATM Turbo 1 -also called ATM 512K- was announced in autumn of 1991. In fact, it was clearly developed from the existing Pentagon board and it had really advanced features comparing to its rivals. It has 512K onboard RAM, 7MHz processor, Centronics port, integrated modem, Covox and Multicolor screen mode - just to mention the most important things. The mainboard was too complex to give a possibility others to make illegal copies, especially thanks to the numerous development of video controller (CGA and EGA level graphics 320x200x16 and 640x200x2 from 64 colours palette). Although usability of these options is quite questionable, as converted PC/EGA games for the ATM (such as Goblins, Prince of Persia) were run fairly slowly even in turbo mode. Despite this, still becomes the dream machine, being in the first row before the (non-ZX Spectrum compatible) Vector. All programs written for the Pentagon 16C mode, are working on ATMs too in 320x200 resolution. For the computer could be ordered a 2x1 watts stereo amplifier. 40 or 64 buttons keyboard could come along with it. Business applications were also available right from the introduction (word processor, database and spreadsheet etc.).

Despite of these impressive innovations, expected success wasn't realised for some clear reasons. Firstly, the mainboard was missing the joystick port - although ZX Spectrums were mostly used as game machines. Secondly, engineers fairly well designed out the incompatible Pentagon-bugs. But at that time, Pentagons became de facto standard in the ex-USSR. So new software all made for Pentagons, and does not work faithfully on ATMs. For third, its price was quite high, costed 5-10 months of Russian salaries. First generation is numbered from v4.10 to v5.20.

The next generation, ATM Turbo 2 saw the light in 1993. The memory can be expanded up to 1024K. Some another new development which worth to mention: IDE controller for HDD and CD-ROM, XT keyboard controller, as well a simplified version of Covox was used. It gets also a serial RS-232C port. And then ATM left the business, making micro-ART the only owner. This move was the clear sign of decade, as ATM computers have no major developments since then. The second generation was enumerated from v6.10 to v6.40.

In 1994 appeared ATM Turbo 2+(v7.00), which was perfectly compatible with its progenitor, only gets some minor improvements. For example, Turbo 1's integrated modem was disappearing, and replaced with an external Hayes modem. The XT keyboard controller was also changed to an universal XT/AT one. Production stopped in 1995-96. Previously secret documents were freed up.

Owners of ATM computers -and those who only dream about it- regarded it the very best ZX clone. Firstly, it is fully ZX Spectrum 128 compatible (running classic programs) and with Beta-128 interface using the new Russian programs are also not serious problem. In CP/M mode, lots of business software was available too.

Until the Turbo 3 mainboard will arrive, NedoPC can deliver green coloured Turbo 2+ boards (v7.10) which are fully "bugfree" and has superior quality than the original Sinclair products. They made 15 modifications on it. Between 2004 and 2006, they manufactured 50 pieces. From 2007 they took again the old developments.

ZX Spectrum +3e Spain Serbia Poland Czech Republic Slovakia Sweden Great Britain Italy

ZX Spectrum +3e is not a completely new machine, but the "enhanced" version of the last official Spectrum, named +3 (must note, that the black +2A and 2B are also can rebuild to +3e, more exactly to +2e, as they have the same mainboard). This machnine is the inventment of Garry Lanchaster from Spain.

Two new modifications were introduced with this machine.

Firstly, the new +3e ROM, and secondly, the possibility of connecting hard disks and Compact Flash cards.

The original +3 ROM was bugfixed, as well extended with new Basic commands. With this, for example, .SNA .Z80 files downloaded from the Internet are directly usable on original Spectrums. These new ROMs are even offered on sale, for owners who are affraiding of the task of burning EPROMs - others can download the ROM image files from the Internet either in English and Spanish language.

Second phase of tune-up is building the IDE interface. In 2000, was a relatively new idea to connect hard drives to the ZX Spectrum. Only Putnik's 8 and 16 bit interfaces were existing. +3e was using the simpler, 8 bit version. Pera's interfaces also will detailed later.

Going through the years, number of IDE interfaces were quickly increased, and this machine also begins to support them. And it is also works fine with Compact Flash cards, which are more popular nowadays.

The Polish Jarek Adamski also get interested in the +3e tuning, and did not wanted to leave out the owners of older machines. That is why he developed the PL3MEM card, which can tune up the 48K/128K/128K+2 and TC2048/2068 machines. Details will come later, Jarek's developments worth a dedicated section.

Until the native support of CF cards was not ready, owners could choose the construction of Jose Leandro Martinez Novellon or Aitor Gomez Garcia from Spain, which will also described later.

At the moment it is compatible with Pera Putnik's 8, 16 bit and CF interfaces, Sami Vehmaa's ZXCF(+), ZXCF+2, ZXMatrix cards, the divIDE(+), MB-02+ and MB-02+IDE interfaces, the ZXMMC and ZXMMC+ expanders as well Jarek's Yamod.IDE8255 controller and certainly with the PL3MEM card, which is contains the previous controller as standard. Philip Mulrane was also integrated it into his ultimate +2A/2B floppy interface.

ZX Spectrum +3s Romania
ZX Spectrum +3s 3rd revision

The ZX Spectrum +3s is a real new development, which is created by the Romanian Cristian Secara (nick: Secarica). Letter 's' is pointing to his nickname. The project was begin in 1989, and some part of it did not finished yet.

Purpose of Secarica was to make such machine, which is compatible with all Spectrums and capable of running CP/M.

Well, the machine is 99% +3 compatible, and has various extras: 14MHz speed, 1024K RAM, 64K vRAM. With shadowing, any Spectrum ROMs can be loaded. Sound source is the AY-3-8910 chip, mass storage units are 2x1.44 megabyte floppies. Picture is sent to RGB, PAL and composite video output. Eight new function keys as well the conventional Kempston joystick port also get the place. The IN#FF video bug found in the original +3 was eliminated, so almost all 48/128K classic games are running fine.

The mainboard was made in three different subversions: first was running at 3,5/7MHz, second is around 3,5/7/11MHz, and the latest is the present. In past times, contained an overlocked 10MHz CPU, nowadays it uses a downclocked 20 MHz one. Unfortunately, the current system will not allow higher speed than approximately 15,5 MHz.

Due to lack of space, two smaller circuits (which were originally the part of the original mainboard design) were realised on separate two smaller boards.

The floppy controller was taken from the Romanian Cobra clone, and the author had to made smaller modifications to work properly with 3,5 HD disks, not only with 5,25 and 8" ones.

The PAL encoder card is an own design. Base resolution is the same of the original machines, but it is offers two another: the hi-res mode and the possibility of switching on and off the horizontal and/or the vertical border. In that case, picture is stretched to the whole screen.

The author is still working about the display improvement of the CP/M mode as well on the final version of real time clock.

Also a problem for the developer to find a suitable case for mounting respecting the size of mainboard. He is still working of connecting submodules, for example building the audio circuit.

On his homepage, some +3 fixes also found, which were used during the development of superclone. The buggy AY sound was fixed along with a stereo tuning. Beeper was separated to the TV speaker, the sound of AY-chip is to two RCAs or sent to the RGB peritel port. In that way DIN cables can used. The already mentioned IN#FF video bug fixing is also on the homepage. He was tinkering composite video output for the +3 and +2A/B too. Basically, it is the circuit of the older 128K/128K+2 machines, which are left out from the last, cost efficient Spectrums. Some hints and tips also found about using and mounting internal 3,5" drives. 180, 720 and 800K disks are useable. Sadly, modern floppy drive units are not compatible, so must hunt for old XT or XT/AT types.

SpeccyBob 2, SpeccyBob Lite Great Britain
SpeccyBob Lite

SpeccyBob name covers two clone prototypes. The normal version (SpeccyBob 2) is an extended clone with extra functions (which are not really extra in the 21. century...). In fact, they are the same as we can found at the modern Spectrums: new video modes, IDE interface, 4 megs of RAM etc. etc.

SpeccyBob Lite is a simple ZX-clone built from contemporary electronics parts. It is only a 48K Spectrum clone, but compatibility at least is 99%. This is not even achieved by Amstrad in the old days...

Of course, the second one is much closer to realisation, you could see photos from the working machine.

SpeccyBob consists of three mainboards – so looking quite different from the original Spectrum.

The homepage is not accessible for a long time.

Chrome Italy

Chrome is the "Italian clone", which was developed in 2004 on the basis of SpeccyBob Lite. Its constructor is Mario Prato, who a decade later created the DivMMC interface as well.

Opposite of its forefather, not only compatible with standard 48K Spectrum, but as well with its 128K brother. It offers various extras, such as the 7MHz turbo mode realized with Z80C processor, and the further introduced +D floppy interface.

By the author's opinion, compatibility reached 99,9%, although some demos do not work perfectly. Size of RAM is 160K, and sound is produced by the usual AY chip in stereo. It has Kempston compatible joystick port and a Centronics interface too. Beside the floppy disk, conventional tape cassettes can used as storage devices. Picture leaded out through a Scart connector. Additionally, a real time clock is also placed on the mainboard.

The machine is consists of 12 chips, and looks very professionally. The developer put it into a self-made black aluminium case.

Updated: 2015. December


ZX Badaloc Italy

Alessandro Poppi’s ZX-Badaloc clone only one (perfectly working) CPLD-based wired prototype exists. Currently, onwards 2008, the project has been running on FGPA basis. Badaloc is "surprisingly fast" in Modena slang, referring to the machine up to 21MHz peak speed. Otherwise the frequency of clock can be varied between 3.5, 7, 14 and 21 MHz in multiple steps. Its basic components three Xilinx CPLDs: the XCR3384XL is the ULA emulator and has two XC9572XLs. One is charge for I/O operations, and the other for the keyboard (PS/2), Kempston compatible mouse (PS/2) and controlling the joystick along with a PIC16F877 microcontroller.

A 20MHz Z84 processor controls the memory chips, the Flashable firmware EP(ROM), the AY-chip (stereofized) and the SD/MMC interface, together with a real-time clock, which one is a Dallas DS 1210/1307 type. By the way, the interface was implemented as a separate project known as ZXMMC card can be up to 32 characters length, the file system is not standardized. Not only ability to read from memory cards, but also from a host PC using UART.

Keyboard controller is capable of handling the conventional 40 keys matrix, so the PS/2 keyboard is not necessary. In case of PC-keyboard, combined key functions are also available. The video circuit of course, was integrated into that CPLD, which emulates the ULA and it is VGA compatible. There are two modes: one is the standard Spectrum, another resolution is 320x256 with 16 colors.

Size of RAM consists from the video memory of the scan-converter (128K) as well the ZX Spectrum memory (128-512K) and the video memory of Spectrum (32K dual-port). Into the ROM slot 27C512 - 27C4001 EPROM (64-512KByte) or FlashROM can be fitted, so 4-32 pieces 16K-ROMs can be stored at the same time. The machine itself able burning the FlashROM.

Sinclair edge connector was managed to build almost to 100% compatibility. At least, the ZX Printer works with it.

A ZX-Badaloc Reloaded is the continuation of previous project, integrated into FPGA circuits instead of CPLD basis. Hence from here comes the alternative, ZX-Badaloc FGPA name. With this solved the main problem, the cable jungle.

Development immediately split into two ways. First was built around a Xilinx Spartan 3E HW-SPAR3E-SK-UNI-G card. Meanwhile, a small, low cost version, based on the Avnet Spartan 3A card was realized as the ZX-Badaloc Nano.

The soul of this subversion is the 3A-400 FPGA. Since the card does not contain either VGA or PS/2 port, so they were implemented on a special mini card. The RS-232 port has been replaced by an USB one. As it does not have considerable RAM, so only able to emulate the 16K Spectrum.

Finally, the two developments was combined onto a Digilent Nexys2 Spartan 3E card, using a XC3S1200E FGPA (it is possible, that Xilinx Spartan XCS500E also be able to manage the project). On the new card, some functions have not been implemented.

They are on a separate board, on the Digilent's "pmod" module were realized, which is containing the cassette, speaker, joystick and SD card interface, as well as the Flash feature. This was drove the LEDs until it was replaced by the OSD. The card would otherwise be able to run the main functions of the clone itself. Has real MIC/EAR jacks and speaker outputs, which can serve the emulated AY-chip (YM2149 core by mikejd). Also though the RCA audio output can be heard both the beeper and the AY-chip. PS/2 keyboard can be also connected to it. It performs serial communication via RS-232 port. Programmable joystick port is provided too. The SD card reader was also remain on it.

This clone is compatible with the ZX Spectrum 48/128/128K+2/128K+2A and +2B/128K+3 machines exception of emulation of lower 16K slow memory. Speed of the processor now also works on 28 and 42MHz with T80 core emulation (FPGA Arcade T80). 8 pieces of 512K RAM in it, for each part belongs the same amount of Flash memory. These are emulated by the RAM, so a wide range of ROMs can be handled by the SPI Flash.

VGA now has 256 colors and the Spectrum mode supports the ULA+ based on Alessandro Dorigatti’s code.

ZX-Badaloc Reloaded on Xilinx Spartan 3E
ZX-Badaloc Nano
ZX-Badaloc Reloaded on Digilent Nexys2 Spartan 3E

ZX Spectrum 2009 Remake Italy
ZX Spectrum 2009 Remake

The ZX Spectrum 2009 Remake Remake is the clone of Gennaro Montedoro from the (very) first day of 2009.

Its main features the low power consumption (360mA), the 100% Spectrum compatibility, and the easy building, which is partly due to the design, which counts 15 ICs less, than the original.

This because the reduction of the number of memory and their controller chips.

It is usable with the original Sinclair power supply. It contains a 'small' tuning facility. As is reality the two 16K DRAMs are 64K ones, so possible to transform to a 128K clone.
Technikai specifikációk
CPU: Z80A compatible 3.5MHz
RAM: 48K used (2x64k DRAM, 1x32K SRAM)
ROM: 16K
Video: 256x192, 15colors
Sound: beeper
Keyboard: original 8x5 matrix
Joystick: --
FDD: --
others: MIC/EAR, TV-out, Sinclair edge connector

Frissítve: 2012. március 17.

ZX Spectrum SE (Chloe) Great Britain Poland

The ZX Spectrum SE (codename: Chloe) is a second generation Spectrum clone, which is the development of Andrew Owen and Jarek Adamski from 1999. Although only only prototype was made, numerous emulator simulating it.

The SE combines the memory techniques of Times TS2068 and ZX Spectrum 128K and adding further 16K for it. So altogether has 272K RAM. After the modding of Jarek the ZX Spectrum 128K part uses 144K, while the rest 128K SRAM is controlled by the Timex. The standard ROM was replaced to a 64K EPROM. From this only utilizes the machine 32K. First one is the modified 128K editor. Second is the 48K Basic ROM with some TR-DOS add-on.

Added a 8K serial EPROM to the AY-3-8912. Thank to it, Timex and Sinclair modes both supported. Output is switchable ABC/ACB stereo. The beeper sounds is coming from the internal loudspeaker, but muted when loading or saving.

Picture is done by the TC 2048 SCLD circuit instead of the ULA, in which Jarek was bugfixed the snow effect. It has more screen modes. Beside the normal one, supports the 512x192 Hi-res, and the Hi-colour with 8x1 attribute cells. Possible to use the two ones together, for example the top half of the screen is Hi-colour, and the bottom is Hi-res. Can be handful with text adventures. Due to the 27K videoRAM, four normal or two Hi-res or Hi-colour screens can be handled.

Available software is primarily emulators: Acorn BBC B (unfinished), Apple I, Commodore VIC-20, Compukit UK101, Galaksija, Jupiter Ace, Phillips Videopac G7000, Sinclair ZX80, ZX81, ZX Spectrum, ZX Spectrum 128K and Timex Computer TC2068 can be the machine. Also emulates the Interface 2 ROM cartridges and Mikro-Plus cartridges.

Chloe 280SE is the series production ready version. The CPU is Z804C0020 at 3.5MHz or 21MHz, with 256K RAM and 32K videoRAM. In the 32K FlashROM the SE Basic IV is the default operating system. The sound is done by the YM219F of course in stereo. As an extra, supports the ULAplus mode beside the Hi-res and Hi-colour.

Chloe 140SE is a simplified version. Can not able to emulate the Times 20xx machines, as this memory region is missing. Comparing to the previos clone, it has only 128K RAM.

ZX128 Lithuania

ZX 128 is a Lithuanian development, which was built on the basis of Leningrad 1 clone. The computer consists of three main elements: the mainboard itself, the video controller and the General Sound card is also could connected to it.

Speed of processor is 3,5MHz, and the size of memory -as the name suggests- 128K. Above that, will contain 32K SRAM, which is responsible for holding different operating systems. In the 64K ROM placed the ZX128 Commander utility too.

The developer was not spared with various outputs. So picture can lead out either by Super VHS or RCA ports. Stereo music made by the Yamaha 2147F chip is ported to two RCAs and a stereo jack. The mainboard also equipped with Kempston, Sinclair 1 and 2 compatible joystick ports.

The real innovation is presenting of USB port. With this, we can use Flash cards as storage devices. This one is under development so far.

ZX128: http://speccy.eclub.lv/


ZXGate project was started on the basis of Bodo Wenzels' ZX97 machine, which is a ZX81 clone. But in this case, the whole ZX81 is integrated into a single FGPA chip. Beside this, it contains three another classic computers as Jupiter Ace, TRS-80 as well ZX Spectrum.

The ZX Spectrum ROM did not get place in the machine, must be loaded separately into the 32K SRAM. All of 48K functions are integrated into the machine. Of course, the author cannot promise 100% compatibility, because impossible to test it with all programmes. The machine has output for monochrome and colour monitors as well has a Super VHS port.

Speccy 2007

Russian Federation

Speccy 2007 v1.00

Speccy 2007 originally launched as a 48K clone, which was built around the Altera EPM7128SLC84-15 programmable logical circuit and the ATMega16 controller. With these, the costs of the complete mainboard was under 50 dollars. Unfortunately -as usual- the compatibility of machine is far from perfect.

In the Kiev living Peter Kitsun (alias Syd) who is the designer of the machine, do not necessary to build a new ZX-powerplant, for example the Pentagon 1024SL must be enough for that. Simply wanted to create an original Spectrum from the nowadays available parts.

We can connect PS/2 keyboard to the machine. Picture drived thorough monitor socket, sound through a Scart port.

The first version of machine (Speccy 2007 v1.00) was released in 2007 December. With this, the .TAP, .TZX and .SNA files downloaded from Internet can be loaded from SD cards with up to 4x speed.

Thanks for the pressure of zx.pk.ru forum, Syd developed further the machine with the members of online community. Speccy 2007 v1.04 was came out in March of 2008, this one is supported TR-DOS.

Next level was the development of molodcov_alex, who earlier announced and began the development of Speccy 2007 v2.00 (or by his words: Speccy 2009). This is a Pentagon 128 compatible machine ready for early April of 2009.

Some days later on the basis of machine, appared on the forum the joint machine of Syd and molodcov_alex, the Speccy 2007 v1.00+128K+AY.

The Speccy 2007 v1.00+128K patch offered for the original machine went to public in end of April 2009. This machine got the Speccy 2008 nickname opposite of its release date (maybe the name points to the evolution stairs).

In 2009 July released Speccy 2007 v1.06. The controller was replaced to ATMega32, because the resources of original were fully used, so was not able to control the AY-chip and emulate the 128K mode. So, this version is a 128K+AY+TR-DOS configuration. The AY-chip got place in a separate sub-card, in a similar way as on first generation Pentagons. Beside that, now SD cards supported up to 2GB.

On 2010 March 26 appeared Speccy 2010, which is succeed the Speccy 2007. The size of the mainboard is the same, but it offers various innovations. For example theoretically not only Spectrum compatible, but through the USB port the FGPA is reprogrammable, so emulating different platforms is very possible.

It supports all functions of Speccy 2007 v1.06 (128K and Pentagon compatible, Beta-disk and AY-emulation, .tap, .tzx and .sna file support).

Innovations in short: S-Video and composite output, Turbo mode (7, 14 and 28 MHZ) as well support of all multicolor modes. With reprogramming the FGPA, it is also possible to use scalable VGA output, Kempston mouse and Gluk RTC support as well emulating various clones with extended memory sizes.

The centre of the board is the EP2C8Q208C8N FGPA. The size of memory can be either 16 or 32 megabytes. An RTC was also built in. SD/MMC cards are supported as mass storage devices.

A lot of connectors integrated into the board: 2 pieces of PS/2 ports (for keyboard and mouse) and the same amount of of joystick and USB ports (although the last one can be option). Video output can be TV-RGB, composite, S-Video or VGA. Sound is 8 bit stereo.

Empty PCB costs 10 USD and ready assembled board is 100 USD.

Updated: 2010. Juny 19.

ReSpecT 48K, ReSpecT-2 (128K).

ReSpecT clone will made on the basis of SpeccyBob project. As its forebear, it has got two variants: ReSpecT 48K and ReSpecT-2 (128K). These clones are the prototypes of Z.A.N. from Russia.

First version simulates a basic 48K Spectrum with again a help of Altera EPM7128SLC84-15 circuit.

Second one offers numerous innovations such as new graphics modes: 256x224, 256x256 and 320x200 with 16 colours. Upcoming novelty in Spectrum terms the 4096 colours palette. From that, we can display 16 colours at the same time on the screen. So it is possible to realise more natural pictures. Beside this, the already mentioned Pentagon 1024SL v2.x's colour -per-pixel mode will also supported. In addition, author is planning to produce the 21 MHz high-speed version.


Neo v1.0

ILoveSpeccy's project is the Neo, which is based on a Xilinx Spartan XC3S400 programmable logical circuit and an ATMega 644 microcontroller. Equipped also with 3 pieces of 512K SRAM module and a SD-card slot.

Its most interesting special feature, that all units of mainboard can be reprogrammed without opening the housing via the USB port. This ensuring limitless possibilities for developing of different configurations.

The following peripherals are supported: VGA output with color-per-pixel ad 4096 colour mode, PS2 mouse and keyboard ports, stereo jack, tape, RS-232C and joystick ports.

The PCB is one-sided, prepared at home by the author, therefore the computer can be easily repeated.


FPGA Speccy

FPGA Speccy board

Alex Freed's FPGA Speccy project was released after the author's Apple II and Elektronika BK0010 (a Russian clone) machines. After successfully making two relatively rare retro replica clone around the Xilinx Spartan3 circuit, the time has come to create a new ZX Spectrum.

The machine is still under development, and not only able to run at 3,5MHz, but has a turbo mode also with 28MHz at the moment, but by the testing programs it will run at 56MHz. So welcome a new speed champion among the ZX clones!

Video output of the newcomer is VGA, because it has much more nice screen comparing to an ordinary TV set. Next stair of development is an IDE interface, in order to read the programs from CF cards. At the moment, .TAP files are loaded from sound card, which is good, but damn slooow.

A 256K EEPROM contains the ROM routines of the 128K Spectrum, which loads into the internal memory (BRAM) of the FPGA at the booting process.


The under development Ant-1024HD clone based on KAY 1024 as it was denoted before. Like another Russian clones, it also uses the Altera EPM7128SLC84-15 circuit.

The clone contains Kempston joystick, keyboard, monitor printer and magnetofon ports. From the HD name seems, that hard disk can also connected to the machine, so on mainboard you can find an IDE controller. This can control the CD-ROM as well.

The VHS cassette sized mainboard will be compatible with DMA Utra Sound Card. Certainly has 1024K RAM and supports the 7 MHz turbo mode.

Pentagon Evolution (Pentevo) Russia

The Pentevo (=Pentagon Evolution) clone was created in 2009 by the NedoPC group in 2009. The name of its authors: Vadim Akimov (LVD), Chunin Roman (CHRV) and Dmitry Dmitruiev (DDp). The motherboard was introduced on Chaos Constructions 2009. Beside the ZX Evo name, also known as ZX Evolution.

Ewgeny 7 was made a new ROM, with which the machine will be Scorpion ZS256 Turbo+ compatible.

It has three subversions as: Revision A, B and C.

The first machine was built around the Altera EP1K50 FGPA controller and peripherals controlled by the ATMEGA 128. The DIP Z840008PSC processor can be run on 3,5 or 7 MHz speeds. The machine contains 4 megabytes of RAM and 512K ROM and equipped with two ZX Buses.

The keyboard and mouse attached through PS/2 ports. It contains a Beta-128 controller, a single channel IDE, SD-card reader as well tape socket. The picture output either can be RGB or VGA. The usual real time clock is also present as well the support of original keyboard and joystick.

The Revision B contains some corrections, and the size of mainboard became smaller and its quality was improved. The 20MHz DIP Z84C0020PEC has the 14MHz running option.

With Revision C, the mainboard changed from ATX to ITX standard, and only the VGA remains as picture output. It also got an USB output. The speed of the QFP mounted Z84C0020FEC remained the same. With firmware update it can be compatible with ULA+.

The creator of ZXM-Phoenix series, Mick in 2011 July made the Pentevo Light motherboard. His main purpose was to studying the FGPA programming in VHDL and Verilog languages. Some cosmetic changes were also made on the revision 01 mainboard. The RGB out was again removed, leaving the VGA the only screen plug.
Technical specifications
CPU: Z84@3.5/7MHz (rev A), Z84@3.5/7/14MHz (rev B, C)
ROM: 512K
Sound: AY, beeper, Covox
Keyboard: PS/2, standart 8x5 matrix
Joystick: Kempston
Mouse: Kempston
FDD: Beta-128
HDD: Nemo
others: MIC/EAR, RS232, USB, VGA, (RGB), ULA+

Updated: 2014. October 04.

Pentevo rev A
Pentevo rev B
Pentevo rev C
Pentevo Light

ZXM-777 Russia

The ZXM-777 is connected to Mick (Mikhail Tarasov)

The machine was built in the spirit of ZX-777 and KAY-256, of which machines centre was the ATF16V8PAL circuit.

Its innovation was the usage of SRAM modules, so can be born the first own-developed machine of Mick (revision 01).

The turbo mode f machine is 7 MHZ, but not only the CPU, but the memory is also accelerated (by the way, it is the 'fast' cache memory of 386/486 era). The mainboard is AT standard. Between 2006 and 2008 two boards were made from revision 01. This was followed by the revision 02 with some minor modifications.

The project was cancelled, as Mick gained the necessary practice for further developments.
Technical specifications
CPU: TMPZ84C00-8, 3.5/7MHz
ROM: 64K
Sound: YM2149F, beeper
Keyboard: standart 8x5 matrix
Joystick: Kempston
others: MIC/EAR

Added: 2010. december 12.

ZXM-777 rev 01

ZXM-Phoenix, ZXM-Phoenix 2 Russia

The ZXM-Phoenix clone is the development of Mick (Mikhail Tarasov). The idea of realization was appeared in the end of 2008 on the zx.pk.ru forum.

The inspiration was based on, that members desired to wanted to remind to their youth. On the another hand, Mick liked to trying out himself in a whole project development.

Development was begin in late 2008, with revision 00. Unfortunately users discovered a bug on the green mainboard, from which 6 pieces were made. By the way, it was targeted to realize without FGPA to bring the look and feel of 90's. The board which contains 71 chips, is controlled by the ATMega 8515 microcontroller. Also integrated on the board Caro's ZX Multi Card controller.

The bugfixed first revision (01) was appeared in May 2009. and made 65 pieces of them again in green.

In 2010, due to the request of members, Andrew Charles (CodeMaster) was produced a new series of 15 boards in China, with blue PCB in that case (revision 02).

In the next year, from the 03 revision mainboard again produced 31 pieces and again in China. The development was co-ordinated by Anatoly Gajvoronsky (Zorel). The new mainboard was integrated the SD-Card controller, the new development of Vitaly Rudegenko (Keeper). Number of chips were raised to 72. Manufacturing was arranged by Dmitry Demyanekenko (ZEK). This board is red colour.

As most fans also wanted a turbo mode, Mick fulfilled their desire. It was created on the base of the turbo mode of ZXM-777. In that way, was born the black coloured 04 revision number mainboard with 74 chips. Location of manufacturing again China, and the number of plates is 16.

In 2012 was constructed the final edition, the revision number 05. In it was realized the 128K lock-up mode, which prevented the problem, when using some 128K only software. With the ATiny 13 micro-controller the power management also solved (the 12, 15 and 45 types also can be used). The number of chips again reduced to 72. The 15 pieces of mainboard set was again made in China.

In the same year, after some bugfixes Zorel was decided another to made another 17 pieces. The board got the 05.1 revision number. The colour went to red again, and again was manufactured in China. The making of the last 21 pieces was done by Vitaly Mikhalkov (MV1971) from 2013.

Worth to note, that in late 2012 released revision 06. But it not became 'official', as it not compatible with the others. Its case, that Mick tried to made Pentagon compatible the video timing.

So the last official version is 05.2, not the yellow sixth, which was made in 15 pieces.

The ZXM-Phoenix 2 clone was born from the modernization of its predecessor from 2010. It was crammed into CPLDs the most important functions (EPM7032 and EPM7064) Memory expanded to 4096KB with SIMM72 modules.

This machine is not only KAY and Scorpion compatible, but also has Pentagon mode.

Some new graphics modes also were introduced. For example the 15 or 16 colours already well-known modes and GigaScreen. The most important is the 15 or 16 colours from 128 colours palette and the 15 or 16 colours Border modes.

The 7MHZ turbo mode is standard (memory runs constantly in turbo mode) just like the VGA output.

In the development, more great Spectrum enthusiast took part also.

Kamil Karimov (Caro)was helped to integrate the previously mentioned controller card. Tkachuk Valeria (Black Cat) was give help to create the audio mixer. Eugene Ivanov (Ewgeny7) take advices how to handle the extended memory. Rudenkomu Vitaly (Keeper) was provided a modificated floppy controller design and a lot of firmwares. Gerasimchuk Sergei (Zloy) took part in the implementation of the Scart interface. Stanislav Yudin (CityAceE) collected the old and new Spectrum fans on the forum. Andrew Shapovalov (Xobbiman) hosted the webspace for the project, until Mick does not made his own webpage. Dmitry Demyanenko (ZEK) designed the circuit of SD card controller.
Tech specs (ZXM-Phoenix)
CPU: KR1858VM1, 3.5MHz; TMPZ84C00, 3,5/7MHz (from rev03)
RAM: 1024-2048K SIMM
ROM: 64K
Video: 256x192, 15colors
Sound: YM2149F, beeper
Keyboard: PS/2 (emulated)
Joystick: Kempston (emulated)
FDD: Beta-128
others: Nemo IDE, RTC, RS-232, MIC/EAR, ZX-BUS, ZC SD-Card Interface (from rev 03)
Tech specs (ZXM-Phoenix 2)
CPU: Z84B00, 3,5/7MHz
RAM: 4096K SIMM 72
ROM: 64K
Video: 256x192, 15 and 16 colors on 8x1 or 8x8, 15 or 16 colors from 128 colors palette, border 8 or 16 colors, Gigascreen
Sound: YM2149F, beeper
Keyboard: PS/2 (emulated)
Joystick: Kempston (emulated)
Mouse: Kempston (emulated)
FDD: Beta-128
others: Nemo IDE, RTC, RS-232, MIC/EAR, ZX-BUS

Updated: 2015. December

ZXM-Phoenix revision 00
ZXM-Phoenix revision 01
ZXM-Phoenix revision 02
ZXM-Phoenix revision 03
ZXM-Phoenix revision 04
ZXM-Phoenix revision 05
ZXM-Phoenix revision 05.1
ZXM-Phoenix revision 06
ZXM-Phoenix 2

ZXM-Zephyr Russia

Development of the ZXM-Zephyr was begin in the end of 2013, as the carrying-on of ZXM-Phoenix. project. While the phoenix recalled the retro age with its circuits, Mick was built the zephyr around the modern FGPA-basics. But in some aspects it is also retro, because the FLEX 8000 which was belongs to the Altera EPF88220A family, not manufactured already, so remained stocks was used.

Creating the clone has two main reasons. First is to implement the ZXM-Phoenix into an FGPA in VHDL language. Second in to integrate the SAA1099 chip into a mainboard. So with the YM-chip altogether, the music is 9 channels.

The memory of the machine is 512 or 1024K with two static RAM modules. The ROM is the 512K AM29F040 FlashROM.

There is an IDE interface and Caro's ZX Multi Card interface was integrated, which is also the part of the phoenix. Of course, it has USB interface. As the machine is totally freely configurable except from a few parts, it is more like a development board, than a dedicated computer. But Mick was 'developed' a ZX Spectrum clone from it.

Altogether 15 pieces were made from the revision 00 and 01 boards.
Technikai specifikációk
CPU: TMPZ84C00-8, 3.5/7MHz
RAM: 512/1024K SRAM
ROM: 512K FlashROM
Sound: YM2149F, SAA1099, beeper
Keyboard: PS/2
Joystick: Kempston
Mouse: Kempston
FDD: Beta-128
others: SD-Card, USB, RTC, RS232,MIC/EAR, VGA, ZX-Bus

Added: 2014. December 07.

ZXM-Zephyr rev 00



Harlequin clone is the development of the ex-ZX Spectrum programmer Chris Smith. So far, this one is the only clone, which has full screen timing compatibility with original Spectrums. Only 48K compatible at the moment, but planned to expand 128K/SE and very hopefully to Pentagon compatible also. The machine has such electronic parts, which are easy to find in every electronic store.

The new clone will have a VGA connector beside the convetional TV output.

The author was started a blog, which is not only good for tracking the full phases of development, but we can study the tricky and difficult operations of the original Spectrum at the same time.

ZX Spectrum Issue 7.

The Netherlands

ZX Spectrum Issue 7

On Rodney Knaap's Sinclair Hardware Projects page can be found the idea of realizing the ZX Spectrum Issue 7 clone.

The purpose of mainboard (from which only the empty PCB is ready since years) to fit inside an original Spectrum, mainly for for those, who wants to revitalize a dead Spectrum.

For the design, used only DIP chips, without any super-integrated circuits. So an average hobbyist also can reproduce his own Issue 7 Spectrum.

Video output is standard VGA, so the original TV output must have be widened. Who are afraid to do that, of course can use a separate cable.

The pinouts of edge connector also do not the same as the original as it follows directly the pinout of Z80 CPU. In that way was more easier the construction of the PCB and also saved some money this method.

Anyway, the pinout is the same, as on the Micro-ZX81 clone. Rodney choose this because of some kind of 'standardization'. So using conventional Sinclair peripherals must be attached a converting PCB or use the rewiring method.

The connecting ports of keyboard also in different position comparing to original, again because of more simple finalization of PCB.

Unfortunately no news since 2006. September 25.

There are also advices on the homepage for repairing the connecting points of the Spectrum's folie membrane.

And introduced the idea of ZX Keybus Interface too. The basic idea of this to replacing the original processor of the PC keyboard to a simple scanning circuit. The signals of that is converted by the Matrix EPROM, which is connected to the Spectrum. Then the Z80 CPU interprets the signals, as they would come from an original Spectrum.

Added: 2010. May 15.

Sparky eZX

eZ80 board

Sparky eZX project is attached to the American Richard Kelson, who became dependant with a Timex-Sinclair 2068.

The machine was built around the 50MHz eZ80 processor, which is a steroid pumped Z80 mostly embedded into webservers.

The author is making the operating system also by himself.

Keyboard will connected via a serial port. Modem and SVGA ports will also integrated. The CPU can address 16 megabytes directly without any tricks.

The constructor not only intended to be the most powerful ZX Spectrum clone, but also the strongest 8 bit micro. In memory, ZX Badaloc FGPA surely overdrives it, and soon Alex Freed's machine will be also faster... so time to hurry!

ZX Spectrum on Altera DE1

Great Britain

ZX Spectrum on Altera DE1

The idea of the FGPA-based ZX Spectrum on Altera DE1 clone was first announced on the DesignSpark electrical developing community by Mike Stirling .

The project contained two main aims. First of all, to create a working clone, second, to document and publish the results.

Some years ago Mike already made a similar project. He was implemented the functions of the ULA into the Altera MAX7000 CPLD. There were no resources left to realize the functions of keyboard. So, the project was "useless', but at least the machine was booted.

On early 2010 decided to realize a similar thing on the Altera DE1 developing kit. The result is the full implement of ULA, Z80 commands, ROM as well the 8x5 keyboard matrix into the card. Outputs are VGA, TV-RGB, PS/2 as well standard Spectrum Ear jack. Programs can be loaded through that, support of SD cards under development.

The system simulates the 48K PAL Spectrum, but 128K version also can be expected.
Technical specifications
CPU: Z80 (emulated)
RAM: 48K (128K under development)
ROM: 16K
Sound: beeper
Keyboard: standart 8x5 matrix, PS/2
Joystick: none(?)
FDD: none
others: MIC/EAR, VGA, TV-RGB

Added: 2010. november 27.

ZX Spectrum on FGPA with 17 inch LCD screen


ZX Spectrum on FGPA with 17 inch LCD screen

The clone of Michal Demin, the ZX Spectrum on FGPA with 17 inch LCD screen was born by a perky idea, Michal found an old ZX Spectrum in the basement, and nostalgic waves came into his mind.

He was searched for the topics, and the ZXGate project caught his attention. Meanwhile arrived a 17 col 1024x768 pixels resolution old notebook screen. The idea was born: a XZ Spectrum with LCD screen.

The basis became the Sparkfun Spartan 3 Breakout FGPA card. It got 2x32K SRAM.

The I/O card is based on the ZXGate's I*/O borad, but Michal added the speaker and the NMI button.

The 'last' card is the LVDS transmitter. This is sending the data to the screen. The 256x192 resolution screen is magnified to 4x with eliminating the border.

The Speccy ROM is placed into the FGPA's internal memory.
Technical specifications
CPU: Z80 (emulated)
RAM: 64K (48K used)
ROM: 16K
Sound: beeper
Keyboard: PS/2
Joystick: none(?)
FDD: none
others: MIC/EAR, TV-RGB, NMI

Added: 2011. February 12.

128Ke Great Britain

All 128K Spectrums have hardware bugs and compatibility problems. The 128Ke would be the ideal 128K Spectrum, based on the 128K+2A. The processor is running at 3.54 and memory timings are also 48K compatible. So basically it is a 48K machine upgraded to 128K, reverse engineered from the 128K+A. The project is coordinated by Andrew Owen. Among the proposed upgrades there are Interface 2 support based on Paul Farrow's circuit, Secara's IN #FF video port bugfix, Alistair Fixing the sound on the Spectrum +2A/+3 hardver patch (which is unnecessary with +2B), as well the Atari compatible joystick and audio in socket.

The 128Ke consists only two ROMs by default. First one is the UK128 Editor, the second is the 48K ROM. This is achieved with the method, that in both ROM sockets are installed the same EPROMs. It is because of improve the compatibility, but we can say goodbye to Keypad. Although its functions are still available from the keyboard. Thanks to Alistair's Flash Rom Replacement for the ZX Spectrum +2A/+3, +2B, and +3B add-on, can be used 2x2 ROM sets, activating the necessary one with a switch. Owen was made some ROM collections, which can be downloaded from Alistair's website.

The handling of AY-chip is also done by the way of the regular 128K machine.
Technical specifications
CPU: Z80A@3.54MHz
RAM: 128K
ROM: 32/64K
Sound: AY, beeper
Keyboard: original
Joystick: Atari compatible
FDD: none

Updated: 2015. July.

Fully integrated ZX Spectrum+ Czech Republic

In the Brno residenting willcz shows, how the fully integrated ZX Spectrum+ looks like. Inside the box, there is a scandoubler (PAL-VGA converter) working as image processor instead of the ULA. Storage is a DivIDE with a cheap CF adapter. The 128K expansion and AY-interface made on the basis of hw.speccy.cz's recipe, the latter received a 3,5 stereo jack as well.

It also features the SIF for WiFi connection. The machine works with 5V with minor modifications, so there is no problem with warming. That's way, instead of the original power supply the power is provided by an unit of an old router.
Technikai specifikációk
RAM: 128K
ROM: 16K
Sound: AY, beeper
Keyboard: original
Joystick: none
FDD: none
others: VGA, CF, WiFi

Hozzáadva: 2011. február

Fully integrated ZX Spectrum+

Leningrad-3, Leningrad-2010, Leningrad-2012 Russia
Leningrad 2010 48K

The story of Leningrad 48K (alias Leningrad -1, Lenin), goes back to 1987. The mainboard, which is designed by Sergey Zonov, was the most easibily manufacturable clone. Thanks to that, it became the base of numerous 'home-brew' and 'brand' machines, despite the fact, that it only contained a Kempston Joystick port as a development. It had 64K RAM, from which the system used only 48K. Some examples for the clones utilizing this mainboard: Spectrum 48 , Ural-48K , IR-30 West , Audio CD-005 , Kontact , CICH-48 , Sunkar.

In 1988, the Composite company developed further the mainboard with Leningrad+ name, which was used in the similarly named Composite clone.

Later, Zonov developed a more easily mass-producable model named to Leningrad-2, which already contained the expansion slot and the connector of contemporary peripherals.

In the Internet-era, more people was reanimated this machine.

Ivan, one of the active member of zx.pk.ru forum, was begin to re-develop his mainboard in the spring of 2007 based on Leningrad-2. After 2 bugfixes and integrating a Scart-socket and ZX-Bus, the creature was christened to Leningrad-3 and finished to green colour in 2007. December 12. The 48K base model is expandable to 128K or 512K with a separate board.

Zst (Sabirzhanov Vadim Mirzhanovich) was made with Leningrad-2010 name his own clone, which got the ZXKit-18 name among his own things. This is mainly repeating the old mainboard with some bugfixes. During the re-design, he was take attention for the more easy future mass-production also. The most important novelty of the blue mainboard is the Flash-chip instead of ROM, and the SCART socket. Release date: 2011. July 17.

In the same year, in November 19. he came out with an improved model, called Leningrad-2012 (ZXKit-020). It has separate Spectrum and Pentagon mode, so handles better the old games. With the Flash-ROM it is ready to support OpenSE Basic and ULAPlus, as well ZX-Bus is standard. This also has the already standard Scart-socket, as well got separate TV and audio out and a printer port.

The aim of the developer was to create a clone close to the original Spectrum. The 1 megabyte RAM FGPA-monsters did not care him too much.
Technical specifications (Leningrad-3)
CPU: Z80
RAM: 64K (48K használt)
ROM: 16K
Sound: beeper
Keyboard: 40 key matrix
Joystick: Kempston
FDD: none
others: MIC/EAR, Scart(?), ZX Bus
Technical specifications (Leningrad 2012)
CPU: Z80
RAM: 64K (48K használt)
ROM: 16K
Sound: beeper
Keyboard: 40 key matrix, PS/2
Joystick: Kempston, Sinclair
FDD: none
others: Flash-ROM, MIC/EAR, Scart, TV-out, audio out, printer, ZX Bus

Frissítve: 2012. január 07.

ZX-One Germany United States Italy
C-One revision 2

Commodore 64 and ZX Spectrum clones in the same machine? Yes, this was regarded as a fairy tale for a long time, but nowadays became truth. Even not only the two machines above, but also VIC-20, CPC, turbo-CPC, Amiga can be found in the C-One mainboard.

The C-One (or C1) is the development of the American Jeri Ellsworth and the German Jens Schoenfeld (Individual Computers) from 2002

This is an FGPA-based C-64 clone, which is similarly to the Sprinter, capable of simulating more machines. For emulating these platforms, so called 'cores' must be loaded into the FGPA, from which two fitted onto the mainboard.

The so-called FGPA extender card contains a new Altera Cyclone 3 FGPA , which is necessary for emulating the new machines (Amiga, Spectrum).

The specification of the mainboard are quite standart nowadays. PS/2 mouse and keyboard, SVGA monitor, IDE and PCI ports, only the audio output is not placed at its standard place. The processor is 65c816 with approximately 20MHz speed. This one is 6502 compatible with 24 but memory addressing. Above this, any 8 bit CPUs can fitted onto the mainboard. Mains specs: 1GB SDRAM maximum, from which maximum 128MB for multimedia of course with DMA access.

The system loads the cores from so-called boot-ROM from either CF-card or winchester. So PC data change is possible and easy. Above the IDE DMA port, there is a floppy interface too, and serial and parallel socket also.

The PAL 48K ZX Spectrum core (v1.0) was made by Alessandro Dorigatti on 2011 May 24. It also supports the ULA+ 64 colours mode beside the standart Speccy gfx mode. At present, .TAP files are supported, .TZXs are not.

The Z80 processor is emulated by the T80 software core. The ULA emulation is based on Chris Smith's ULA book (see later). Although among Dorigatti's work this emulating the less precisely the original Spectrum, all test programs ran without any errors (of course, excepted the routines, which are indentifiyng the CPU). As the C-One mainboard does not contains SD-card socket, only two IDE-ports, the author does not planning its further development.
Technical specifications
CPU: 65c816@20MHz
RAM: 16M-1GB
ROM: 512K
Video: 256x192, 15 colours; ULA+ 64 colours
Sound: beeper emulated (8 ch. stereo DMA)
Keyboard: PS/2
Joystick: Kempston
FDD: ?? (reserved)
others: VGA, audio in/out, Centronics, RS232, IDE DMA, PCI

Frissítve: 2012. június 08.

Turbo Chameleon 64 Germany Italy
Turbo Chameleon 64

This multi purpose C64 expansion card is the product of the already known Jens Schoenfeld (Individual Computers) and the similarly German Peter Wendrich (Syntiac.com).

The development began in early 2006, the project was originally titled VGA-64. It was constructed to double the picture of C64 and lead it out to VGA monitor.

As the FGPA left too much opportunity opened, it was further developed to a multi purpose C64 expansion unit. Even it works as a complete configuration without the C64.

Developers now are concentrating more to this device rather than to the C-One board.

Again let's skip the C64 specific parts, let see what contains the v2.0 core by Alessandro Dorigatti.

The core can be downloaded from the website, and can be 'flashed' with the USB cable, just like with the another configurations.

This emulates at 'medium level' the original Spectrums, fits between the C-One and V60Z80P. This already emulates both 48K (PAL/NTSC) and 128K (PAL) Spectrums, along with AY-support. Also ULA+ 64 colour compatible.

The mass storage is the FGPA adaptation of the Italian ZXMMC+ interface. The main operating system is Garry Lanchaster's ResiDOS with TaskMan and TapeIO preinstalled.

The Kempston joystick is emulated on the PS/2 keyboard's numeric pad, or on the CDTV remote control unit.
Technikai specifikációk
CPU: ??
RAM: ??
ROM: ??
Video: 256x192, 15 colours; ULA+ 64 colours
Sound: AY+beeper emulated
Keyboard: PS/2
Joystick: Kempston (emulated)
FDD: ?? (reserved)
others: VGA

Frissítve: 2012. június 23.

V6Z80P Great Britain Italy

The V6Z80P is a complete new FGPA-based 8 bit computer architecture from Phil Ruston.

Its hearth is the Xilinx Spartan 2XC2S180 FGPA and a Z80 at 20MHz. The memory size is 512K, which is used both by the Xilinx and Z80. It has further 512+128K RAM, which used by the FGPA solely.

In Phil's config the OSCA config (Old Skool Computer Architetkture) runs the FLOS (Freezer Like Operating System).

A Pendulum daughterboard was also made for the system, directly designed for enhancing the memory timings for ZX Spectrum emulation. It was done for the request of Alessandro Dorigatti who made the ZX Spectrum core.

The v2.3 core is emulating the ZX Spectrum 48K/128K and Pentagon 128K machines. The 48K emulation works in PAL and NTSC mode. The last two machines only in PAL. The Pentagon mode uses the special memory timings of the Russian machine.

It emulates two AY-chips in ABC-stereo mode, as well a mono Covox. Can be run at normal 3,5MHz or turbo 7MHz speed. The picture is led out through VGA or Scart output. It uses the Issue 2 keyboard for better compatibility. Supports the ULA+ 64 color mode, the Timex Multicolor, the Timex Hi-res screen modes, except in Pentagon mode to achieve better compatibility.

The virtual DivMMC interface is also part of the system. (DivIDE with 8K EPROM and 256K RAM and ZXMMC+ interface with SD card support). Its main operating system is Miguel Guerreiro's esxDOS. The Kempston joystick can be used in port 1, as well there is a possibility to load the programs from external source with a 3,5mm jack, if you want it instead of SD card.

Updated: 2015. July.

Pendulum v1.1
Pendulum v1.1b

ZX Spectrum on pipistrello Hungary Spain

The aim of this project to create such ZX Spectrum clone, which has HDMI output. Laszla Jozsef (aka Joco) choose the Pipistrello FPGA card, which is based on the Spartan-6 LX45 FGPA, here is the ZX Spectrum on pipistrello name from. It is because it has HDMI output, the FGPA is enough large, and the 64 megabytes of DDR RAM is enough for everything.

For the creation he was used Miguel Angel Rodriguez Jodar's FGPA ULA implementation, as well Mike Field's (hamster) VGA-DVID project.

He was choose the 720x576 resolution with 50Hz refresh rate, the closest to the Spectrum. Speccy is using 7MHz for timing, HDMI 27MHz. Joco was set the machine to 28MHz (4x7) to achieve timing compatibility. Quite interesting, works fine with the TV, although uses only 524 lines instead of 625.

Steps are the following: porting Miguel's code onto the LX45, as well to upscale the picture. Then to connect it with the HDMI interface.

The PS/2 interface and the EAR is also realized inside the FGPA, last one is based on the Issue 6. The sound of Spectrum can be heard through the audio output of the card.

The result is fine, 99,5% faithful emulation in this card made in 2013.

Added: 2015. July.

ZX Spectrum on pipistrello

Multiple Classic Computer United States Italy

The MCC, also known as Multiple Classic Computer is a console, which can emulate some old machines. Can be mimic Commodore 64, Amiga 500, Atari 2600, Atari 800XL, Apple Iie, and which is the most important for us, also the ZX Spectrum. It is the product of Arcade Retro Gaming located in the United States.

It has two subversions: MCC-216 and MCC-TV Their common features, that the CPU, sound generator and interfaces are freely configurable in the Altera Cyclone 3 FPGA, and they have 16 megabytes of SDRAM. All of them have stereo output, and programs can be stored on MicroSD card.

The MCC-216 has 2 megabytes of Flash memory, in which of course could fit the programs alongside the confogrations. Also has PS/2 mouse and keyboard connectros. The picture output can be either S-Video or VGA.

MCC-TV has composite TV out. Unfortunately, its Flash memory only 128K(?). But has two USB joypad connectors. (USB v1.1).

The ZX Spectrum core by Alessandro Dorigatti is usable on both machines, but sadly, only the v1.0. So we get a 48K Spectrum in PAL or NTSC mode. The Issue 2 keyboard is emulated for better compatibility. Floating Bus and Snow effect are also emulated successfully. Also available the ULA+ 64 color mode and the ZXMMC+ interface with 512K+SD card interface combination.

The Kempston joystick emulation works on both Atari and USB ports. It arrives with Garry Lancaster's ResiDOS-a with TaskMan and TapeIO preinstalled. We can load the .TAP files from the Launcher menu made by Arcade Retro Gaming itself.

Hozzáadva: 2015. July.

MCC-216 (S-Video)
MCC-216 (VGA)
MCC joystick

ZX-Uno Spain

The ZX-Uno FGPA-based clone (mo' exactly the card) is done by five Spanish guys, well-konwn in the Speccy scene. McLeod_ideafix, Miguel Angel Rodriguez Jodar is the PR-manager, SuperFo SuperFo (Watchara Chantang - originally a guy from Taiwan) is the PCB dezigner, AVillena (Antonio Villena) is the father of idea, circuit and prototype dezigner, Hank0 (Jordi Bayopedig) is the gfxman and web dezigner. Quest - Samuel Baselga is a new member, also involved into PCB and schemtics design.

The clone exists only at hardware level at the moment, programing of FGPA is undergoing process. The 512K SRAM is limiting the number of machines: maximum size of RAM(s) and ROM(s) can be 512K.

The machine fits into the RaspberryPi case, most outputs are designed for it. The RCA video, stereo 3.5mm jack, SD card and power micro-USB in its original place. Atari joystick placed into the USB hole, the JTAG/RGB is in the HDMI, PS/2 keyboard slot mounted into the Ethernet socket. But it is necessary to drill the place of tape port. Unfortunately, for cost effective reasons (at least at the moment) nor the Sinclair edge connector, and nor the USB keyboard is not implemented.

From the .TZX, .TAP, .DSK and .TRD files, only the .TAP will be surely supported on the SD-card. Others are big question mark. Maybe the HxC will be implemented into the FGPA core.

Beside the Spectrum, the Russian clones, the SAM Coupe and more simple machines (ZX80, ZX81, Jupiter Ace, Z80 PacMan etc.) also can be realized.

Made in two subversions. First one is a 22 Euro developer edition, on which the parts not mounted onto the PCB. 10 pieces were already made. The end user edition will be around 30-40 Euros, and it is fully assembled and programmed. 50-100 pieces is the sale plan from it.

Updated: 2015. November.


Dual-CPU/MCU development board

Dual-CPU/MCU development board

The main idea of constructing of Dual-CPU/MCU development board was drafted by the pandora.cz newsgroup. To summarise: create a new platform, which is ZX Spectrum compatible. The board is married the good old Z80 and Z8Encore! processors.

Hearth of board is the Z8Encore!, controlling all another peripherals, even the Z80, beside the serial port, LCD screen as well the memory.

The prototype worked fine, but the developer is trying to make further innovations of the original ZX Spectrum design. MMC card interface, 512K RAM support, keyboard-port (original ZX Spectrum layout and PS/2 standard) will hopefully integrated. In addition, the Z80 will also support the peripherals, which are only used by the big brother momently (UART, IrDA, I2C).

The actual Nokia mobilphone screen will also be replaced with an original ZX Spectrum resolution one by the plans of the designer.

Sadly, last update was in 2004.

aSPECT development board


The aSPECT development board is a development device for enthusiast Spectrumists from aniSKY. The card saw the light in 2010 in the Belarusian Minsk city.

Consists of four circuits: the ALTERA EP1C6T144 (or alternatively the EP1C6T144) FGPA, the configuration ROM, 128K SRAM, as well 256K Flash EEPROM.

Supports the basic Speccy functions as keyboard, kempston joystick and video controller.

Another I/O functions of FGPA is reserved for controlling and testing the modern devices (SD card, IDE, USB ports etc.).

Added: 2010. February 26.

Aspect 128 AVR ZX Spectrum Russia

Aspect 128 AVR ZX Spectrum
The Aspect 128 AVR ZX Spectrum board is the work of Vasil Lisitsin radio-amateur from 2012. This development is compatible with 48K/128K/+2/+3 machines as well with Pentagon. Further more, it is virtually capable of emulating all clones up to 512K.

All documented and undocumented Z80 commands are emulated within the ATMega-16AU circuit. Here are the I/O commands also. The PS/2 keyboard is controlled by the ATTiny 2313A-SU. The card is also handling the shadow screen.

The whole project is detailed and documented on one of the most significant radio amateur website.

Added: 2013. March 29.

Just Speccy 128k Spain

The Just Speccy 128k mainboard is the clone of Zaxon (Piotr Bugaj). This one is 128K compatible one, which fits into the 16/48K(+) cases.

The storage is PicoDivSD, which is the own DivMMC clone of the author (an advanced DivIDE development) and runs the esxDOS operating system. Also got the Kempston joy interface. The RGB picture comes from a 8 pin mini-Din socket. It contains the usual AY-stereo mod.

Added: 2016. January

Just Speccy 128k

TBBlue Brazil

The joint project of Fabio Belavenuto (FB Labs) and Victor Trucco (VTrucco)is the TBBlue clone. After the successful re-engineering the ULA, was raised the idea of this FGPA-based development. This contains several clones and peripherals. Beside the 48K and 128K Spectrums, the Brazilian TK90X, TK95; ZX Spectrum 128K+3e, ZX80, ZX81 and Jupiter Ace can be configured.

DivMMC DivMMC became the mass storage with esxDOS support. This can handle maximum 8 Gigabytes of FAT32 partitions. From this loading the firmware ROMs and programs in .TAP format.

Sound is AY-3-8910 and YM2149 emulation through stereo jack, MIC and EAR got separate connectors also.

Two joystick ports are also fitted, can be configured as Kempston, Sinclair and Cursor 2. To the second port with a PS/2 adapter can be connected a mouse or lightpen.

The favourite device of crackers, Multiface was also integrated which operates as One, 128 and +3 mode, depending on the choosen clone.

Standart PS/2 keyboard/mouse (Kempston compatible) and VGA connector also can be found. Supports the ULAPLus mode too.

Finally was realized in two flavours. Fabio was designed it to fit into a box. Opposite of it, Victor’s board can be placed inside the case of the original 48K Spectrum or TK90X/TK95.

For all of two must be bought separately the FGPA card (EP2C5T144 Mini). First is from 2015, last one was born in 2016.

Added: 2016. April

TBBlue by Fabio Belavenuto
TBBlue by Victor Trucco

ZX Spectrum Next Brazil Great Britain

The ZX Spectrum Next clone is based on the previously shown TBBlue. Its design (which only exists in 3D rendered form yet) mixing the design of ZX Spectrum+ with modern elements.

The manufacturer will be SpecNext Ltd. founded in February 2016 in London, as the cowdfunding will give the possibility. Specifications mainly the same with the earlier clone. Next things can be known.

The CPU will be a Z80 on 3,5/7 MHz with 512K RAM. Picture beside of VGA and RGB out also will realized on mini HDMI with a Raspberry Pi Zero.

An additional accelerator board will be fitted into the machine too, with its own GPU, 1 GHz CPU with 512Mb of RAM.

Added: 2016. May

ZX Spectrum Next

Beta Disk Interface Great Britain Russia Czech Republic Slovakia Brazil

The system of British Technology Research Ltd. - similarly to another floppy disk systems – never became dominant in Europe in traditional sense. Despite of the fact, that in its time has very attractive parameters.

However, in two countries as Brazil and Soviet Union they almost exclusively were widespread as mass storages.

First version was the Beta Disk Interface (aka Beta-48) which came out to the market in 1984. Up to four units can be connected to it, 3, 3.5, and 5.25 inch ones (a: b: c: d: drive). One or two-sided, single or double density, 40 and 80-inch track disks can be used. Capacity of double-sided DD discs are 640K. Disk drives are powered via the interface.

Most notable innovations were the Magic and reset button beside the auto detection of parameters of floppy disks. The "Magic Button" saves the contents of RAM to disk.

In Brazil, this version became dominant. Several Beta-48 compatible interface existed in the country (CAS, CBI-95, AR-20, MID-185, IDS). Among them, nowadays Victor Trucco was choosen the IDS 2001 model to rebuild.

The German Midas company's product is Gammadisk, who further developed it with adding printer and Kempston joystick ports. Latter ones thanks due of the three-port 8255 PIO controllers. This interface uses the TR-DOS version 4.12. Also received an NMI button. A curiosity: the 27C256 EPROM has two pieces of 16K banks. A modified ZX ROM placed in the first, other has the TR-DOS, and first one remains hidden from the machine.

In 2015, also in Germany, Klaus-Peter Casper was reconstructed it again. On his website can be viewed the documentations needed for making one.

Beta-128 Disk Interface (or simply Beta-128) was developed for the 128K Spectrum. The 1987 novelty has retained its predecessor’s file format, but was not compatible due to changes in the ROM.

Reset button was disappeared, and replaced with a combined "system switch". Its middle position is the 48K mode, 128K is the right, and left is the 48K reset. In 128K mode, must use the own reset button of machine.

This was imported into the Soviet Union and manufactured from Russian parts. First Russian version of it was developed in 1989 by firm Option in St. Petersburg. First clone, which was used it was Leningrad in the same year. Soon they hacked the 5.xx original versions of TR-DOS and own 6.xx-ers have taken their place. But more about that later...

Beta-128 has become so de-facto standard, that it does not spread as a separate interface: on majority of clones was integrated into the motherboard (such as the Pentagon, Scorpion).

First TR-DOS programs were disc adaptation of classic games. So the 5-minute loading times were decreased to few seconds. Since capacity of disks were 640K (or using compression even more about 800K in case of games) it was common making thematic game compilations and by a menu can be chosen among them (arcade, sports etc compilations).

Next step was the rewriting the relatively large capacity PC DOS and Amiga games to Speccy (Prince of Persia, Ufo, Civilization). Some games fill up to two disks, Seasons of Sakura (16C) has three floppies! This was led to born of very high quality games. Such programs were released, from which even the press also wrote, that it is impossible to made their Speccy version.

Some companies have developed special Beta-128 interfaces of their clones. In the KAY 1024 found Nemo bus version already mentioned above. Peters company also come up with their own bus system to match the interface of their Contact clones. Some simplified versions only supports two disk drives, such as Scorpion. The new HD system has 1,7Mbyte capacity, although was did not widespread.

It was spoken about the cracking of original TR-DOS. Crackers were optimized code for faster operation and new functions have also been introduced in the system. This example is the aforementioned HD discs, the auto-boot, quick formatting and turbo loading - just to mention the most important ones. Latest version 6.10 (Mr. Gluk), 6.12 (Power of Sound) and vTR-DOS (developed for ATM clones).

Beside the TR-DOS; IS-DOS, Vision OS, DNA OS and a special version of CP/M can be the operating systems of the interface.

HR-DOS is the hacked version of TR-DOS. Interestingly, while the operating system was expanded by adding a printer utility - however, the code size is halved. Russian coders must know something!

Beta-128 was also cloned at the territory of the former Czechoslovakia, although it never reached such an outstanding success as the D40/D80.

Since originals are very difficult to obtain, for the request of Spectrum community Victor Trucco and Piotr Bugaj were reconstructed it.

Tetroid from from Novosibirsk was also constructed a small series of a Beta-128 clone.

Velesoft began a project too, that would have been a combination of Beta-128 with a real-time clock, an SD card reader, 512K SRAM and the same amount of FlashROM, which would have included the DivMMC routines as well.

Updated: 2016. August

Beta Disk Interface (Beta-48)
Gamma disk
IDS2001 clone
IDS2001 clone plus
Beta-128 Disk Interface
Beta-128 clone by Pavel Cejka
Beta-128 clone by Velesoft
Beta-128 Plus by Victor Trucco
Beta-128 clone by Piotr Bugaj


G. Shell

CDOS (Communication Data Operating System) is the second, not so widespread operating system in the ex-Soviet Union.

It name comes from CDOS interface, which is a modem+disc combo released in 1989. Beside the Spectrums, it is compatible with the American Timex 2048 clone too.

First version of CDOS operating system was a product of the firm Allegro in Moscow. Continuing the good-old Russian conventions, cracked and improved versions are rapidly appeared in Moscow, Saint Petersburg and Minsk (for example by KSA, Fantomassoft and MPR).

This interface is a multifunctional one. Beside the modem, it uses 5,25" or 3,5" 800K disks, even some versions contain 256K RAMdisk as well real time clock. If no built-in RAM found, it can use the own memory of the computer. Some versions equipped with Centronics port too.

Get bored loading your favourite utilies? Do not panic, CDOS also has 128K ROMdisk, to make these accesses really fast.

On the picture G. Shell. seen. Russians are not only copying the hardware, but the same can be said about software...

Most users only used the modem part of the interface, which was replaced to Hayes modems in most networks.

The very last CDOS network was SpbZXNet in Saint Petersburg, which was died in the end of 2002. Moscow and Minsk centres were died earlier.

D40/D80 (D40B/D80B)

D40 and D80 drives

D40 and D80 disk systems originally developed for the Didaktik machines. D40 uses 360K 5,25" disks, D80 is supporting 720K 3,5" ones. If really wanted, disks can be formatted up to 420 or 840K.

Quite clear, that the company is adopted the MS-DOS system, even the name of operating system is very similar: MDOS. After all, not surprising, floppy drives are standard IBM PC units. Drives can be connected directly to any 48K Spectrum with a ribbon cable, which contains a snapshot button.

Kompakt already has a built-in 3.5" D80 drive, one more D40B or D80B connectable for the machine (the name refers to the b: drive, they are without power supply types).

Only one drive must have external power supply, another can be a B-type. The manufacturer was tested them not only with original Spectrums and Didaktiks, but also with the ex-Jugoslavian Deltas.

MB-01/MB-02/MB-02+/MB-HDD1-2-3/MB-03/MB-02+IDE/MB-04 Slovakia Czech Republic Germany Netherlands

The history of interface is roots back to the early 90's. At that time decided MDV (Robert Letko - Robo) and Busy (Slavomir Labsky) that it is high time to develop a floppy interface for the ZX Spectrum to retire the good old tape. First, only imagined a DD unit, but later raised the idea of a HD system as well (because such interface did not existed at that time for the microcomputers).

For realizing this, was not enough the Spectrum's own CPU, so a special Z80-DMA circuit must be designed, which was later also used like a kind of graphical co-processor ('the poor man's Blitter'). Finally, the MB-01 was created in 1992 with 2x64K battery backed SRAM. There is no information the total production number of MB-01. The name consists of the initial letters of MDV and Busy and the version number (01). Originally was named to AP-01.

The Palenicek-brothers (JSH - Oldrich, and Omega - Jan) were also interested in the interface. They were so impressed, that immediately wanted one. Busy sent them to MDV, who gave them an enhanced version, the MB-02 (without 'plus').

The interface was consisting of two smaller PCBs, and placed into a hand-made black box with 128K SRAM powered with two AA batteries. The board was also contained a memory extender slot (theoretically expandable to 4 megabytes), a Kempston, and printer port as well an NMI button. Anyway, the completely hand-made interface was fully compatible with the later serial product except for the memory paging. But as the BIOS and DOS is separated, it does not serious problem. Only two pieces are exist in the ownership of Busy and Omega. Accordind to the text on the PCB, it was made in 1992.

JSH was promoted the interface on various events in the Czech Republic and in Germany (for example on Samcon'94/95, Zlicon'96), then took it to 8 Bit Company (in the further promotion JSH was also actively involved).

Here a bit enhanced and professionalized the interface. Was realized on a large, single PCB, and now button-battery powered was the memory and now the optional real-time clock also. Thus was born the king of ZX Spectrum peripherals (and so also the 8 bit micro's), the MB-02+ in 1995. Until 2001. December 16. a total of 70 pieces were sold due to the fairly high costs. They were made in professional quality, but totally hand-made.

Now the detailed technical parameters. Disk capacity is 1.8 megabytes in case of HD disks, and 840K for DD floppies. Transfer speed is between 40-50K/sec or 25K/sec for the previous disks. 2K EPROM is in the interface, and a three channel, bi-directional parallel port (i8255). Kempston and Amiga mouse compatible port also soldered. Two floppy drives can be attached, but with a special hub, it can be up to four. The default 128K SRAM can be used as RAMdisk, as drive 9 (direct access is not possible).

The biggest advantage of interface, that it is fully compatible with the tape system. So does not necessary to write new loaders, just have to copy the files. Of course, as a Czech product, also compatible with the D80 system. This is achieved by the ed80 software emulator.

The operating system is BS-DOS (named after Busy) in which 256 directories and 65.279 files supported. After all does not necessary to explain the origin of names BS-ROM and BS-BIOS, which are built into the interface. By the way, version number of DOS is 3.08, the 4.00 was never released. On the box, a reset and NMI button was also placed.

The manufacturer beside the original Spectrums also tested on the ex-Yugoslavian Delta and on the Didaktik Machines. Sintech in Germany also sold this product.

The MB-02+ often mentioned as the pioneer of Multicolor and Multitech Monochrome screen modes.

Velesoft was realized more of its parts in the new age. He was reconstructed the Z80-DMA circuit - which was originally published in the 1998/08-09 issue of Your Spectrum magazine – in 2005 with Data Gear name. Not only works with Spectrum, but for another Z80-based machines (Scorpion, SAM Coupe). For the faster machines the DMA chip must be 6-8MHz instead of 4 MHz. He was made two series from it in 2005 and 2007.

The MB-02 memory interface is from 2008. This is a MB-02 RAM-disk compatible thing, which contains 1 megabyte of battery backup RAM. Can work in two modes: full 1 megabyte of RAM; or 512K RAM and 512K ROM. It works fine together with any other interfaces, and has a DivIDE compatible mode.

During the history of MB-02+, a number of hardware and software patches were born from the developers and of course from the fans as well.

One of the most important is the 'single chip 512K SRAM tuning' by Poke Studio (Petr Petyovsky). We can control a half-megabyte superfast RAM-disk in that way (introduced: 2006. January 05.).

Flash Utility (I) and Flash Utility II Last Monster's (Jan Kucera - LMN/8BC) innovations from 2000 and 2008. First is changes the default 2K 2716 EPROM to 32K 29C256, the second one can extend it to 64K or 128K (also divided into 32K banks). In this case 29C512 (64KB) or 29C010 (128KB) EPROMs must be used. Z00m (Branislav Bekes) was further developed the first method, and published it under MB-02+ modification–28C256 name. It uses 256K EEPROM. The flashing can be done with LNM's own program, but z00m also made a slower one, in the case of compatibility issues. Anyway, we can read about it on the Hw.speccy.czwebsite, maintained by the author.

The next hardware innovations, MB-HDD(1), MB-HDD2 and MB-HDD3 IDE controller add-ons made also by Last Monster. These based on the internal interface developed by PVL (Pavel Riha) and Tritolsoft (Lubomir Blaha). With increasing the version number, the size of PCB was reduced and compatibility was improved. The dates of each version: 2002. November 11., 2005. December 12. and 2008. May 18. The size of board was designed to fit comfortable into the house of MB-02+. However, can be used without the MB-02+, with a standalone Spectrum.

For booting from HDD unfortunately needed a floppy, which installs the winchester. For fixing this issue developed MB-Maniax group the FlashBOOT upgrade (v1.: 2007. november 26.). It needs the Flash Utility I or II modding, as it quite difficult to crucnh it into the factory 2K. If it is ready, we can start the flashing, and also handful to burn in the most used utilities for contorlling the MB-02+.

Later more newer versions were created by the community consist of Czech and Slovakian Spectrum fans (FlashBoot v1,1: 2007. December 05., v1.2: 2007. December 08, v1.3 aka JHCon version: 2007. December 17., v4: 2009. August 23.).

In January of 2002, first news came out from the successor, the MB-03(+) on the comp.sys.sinclair newsgroup. This was announced by Jan Werner, one of the editors of Speccy.cz portal. Among the planned specifications were 512-2048K SRAM, 32K FlashROM, PS2 keyboard and mouse, IDE interface and an SD-card reader.

So basically the same as a tuned-up MB-02+. Most costs of development generated by integrating the whole card into a small integrated circuit. Because of that, planned price was 300 Euros (in case of 50 pre-orders). Rumors also mentioned integrated General Sound soundcard. Since, no news from the MB-03(+).

But most development of MB-02+ was realized in the MB-02+IDE interface created by the German Ingo Truppel. The parameters of interface are mostly similar to the planned MB-03(+). Of course, the interface is compatible with the original, as based on its circuit diagram. But has a notably smaller size, because Ingo realized it on a four-layer PCB.

Kempston and Centronics ports are also built in, just as a real time clock. Contains 512K RAM as standard. The most important feature of course is the IDE interface, which also supports CF cards (Ingo constructed his own CF-IDE adapter). Got also a reset and NMI button and 2 LEDs, indicating power and IDE operations. All MB-02+IDE has these features.

From The Netherlands also came news from the further development of the board. Ben Versteeg was working with full power the realisation of MB-04. 512K RAM, Z80 DMA, IDE interface, CF-IDE adapter, mouse and keyboard ports were planned. The prototype with some exceptions worked fine both with 128K+2 and +2A machines. Ben wanted to split into two the fairly big sized board: into the first would integrate the Z80 DMA, mouse and keyboard controller. Another components would fit into the second board, which connected with a ribbon cable to the first one. Since Ingo Truppel released his own board, development was abadoned.

One of the manufacturer and trader of DivIDE, Noby (Noby Noblnoch) wanted to re-produce the MB-02+. But as assembling time would twice as long as for DivIDE, Noby stopped the reincarnation project of MB-02+. By the way, its planned price between 120-150 Euros.

Updated: 2014. Augusztus 02.

Data Gear 2007
MB-02 memory
MB-HDD 2.0
MB-04 prototype


SMUC v2 rev A

Scorpion's solution for combining the ZX Spectrum with hard disks was the SMUC (Scorpion and Moa Universal Controller) IDE-controller. In its name it is refers to Andrew Moa, who was the co-developer of this card inline with Scorpion.

Two HDDs can be attached to the card, just like to as its PC-ancestors. You have to copy the original TR-DOS disks track-by-track onto the hard disks. It works with up to 4 "virtual" Beta-128 drives - a:, b:, c: and d: disks (in a very similar way, as you use a software ZX Spectrum emulator).

SMUC is compatible with TR-DOS, IS-DOS and a special version of CP/M operating system.

2K NVRAM is fitted as standard on the board for storing the tuning-settings as well the datas of HDDs. Real time clock is also easy to install for the SMUC. Just plug the Dallas DS1287 chip into the prepared slot and it will work. Many other PC-compatible peripherals also connectable for the SMUC, for example Hayes-modem.

As Scorpion’s stocks were sold out, members of zx.pk.ru decided to create a similar universal controller with backward compatibility to the original (SMUC v1.3). It got new name, which has the same abbreviation: Spectrum Multi Unit Controller v2.0 rev A.

With the card, not only winchesters, but also CDs/DVDs, CF-cards (with adapter) can be connected to the computer.

Compatible with the followings: KAY-1024, Scorpion, Pentagon 1024, ZXM-Phoenix.

Can be ordered from Witchcract Creative Group.

Updated: 2010. January 16.

NemoIDE Controller

NemoIDE Controller by Perspective Group

For attaching hard disks and CD-ROMs, Nemo company also developed their own interface in 1998. Of course, originally built for the KAY clones, but thanks for the simplicity of circuit, became popular on Pentagon, Scorpion, Profi etc. clones also.

The initially quite buggy card was further developed by anothers and NedoPC also introduced their own version, which remained in production till 2006.

Can be ordered through Perspective Group too, which is a bugfixed 2005 version.

Witchcract Creative Group also produced his own version, they are offering it for KAY, Scorpion as well for Pentagon 1024 SL and ZXM-Phoenix 1024.

This product is not made in huge quantities, but available for pre-order only. On the photos seems, has different subversions. The card is not only available as a ready-made product, but you can also obtain as a printed circuit board.

Its operating system is iS-DOS. Above that, Mr. Gluk made a cracked version of TR-DOS 5.30, which supports the IDE devices in conjunction with the DNA OS.

Updated: 2010. February 13.

DivIDE and its clones as well its further developments Serbia Czech Republic Slovakia Germany Poland Great Britain Netherlands Italy Brazil Russia Portugal

DivIDE -as the name suggest- is an IDE interface originated from the Czech Republic. So far this is the only device in the 'new age', which became some kind of de facto standard interface internationally.

Before getting know about the interface, let's begin with its pre-history.

The ZX-IDE interface is the joint development of PVL and Tritolsoft from 1999. This one is an internal variant, which is also the first version of MB-HDD built into the MB-02+.

For the authors, Matsoft (Matej Kryndler) brought the Serbian Pera Putnik's interface diagram downloaded from the Net. Its main problem was since the IDE HDD is a 16 bit device, and the Speccy is 8 bit, therefore the capacity of hard disk will automatically half of the nominal. So, the single I/O channel has been replaced to a six channel I/O structure. With this, and a special backup method, the full capacity can be used. The interface can handle two IDE devices (master and slave) at once.

The MB-02+ compatibility was solved by dR0n (Jiri Sleka). With the HDD_patch utility 2 megabytes of virtual disks are used. Later version of the program is also supports LBA and DMA modes.

The next step is the external version of ZX-IDE interface prototype, which was never released to public. Busy has also helped in its implementation in optimizing of reading and writing operations. 64K EPROM, 128K battery backed SRAM and an NMI button were the main new features.

In 2002 February released the wired prototype of DivIDE 42r2 from Zilog (Zilogator, Pavel Cimbal, xcimbal). This was mainly based on the ZX-IDE interface, but returned to Pera Putnik's more primitive read-write operations. Contained 8K ROM and 32K RAM memory.

The first public version was DivIDE 57, mostly spread among the Czech colleagues from August 2002. Worth to mention, that Cimbal was made it without any testing, so made the first one from scratch – and it was working.

This was followed by DivIDE 57b, in which the IDE connector and NMI button was moved to a better position (aka 'facelift').

The most widespread model, DivIDE 57c is the same, but on the board the jumpers are signed with different characters. It has some electronic modifications. Also can be ordered the whole stuff from Divide.cz webshop, which is ran by Factor6 (Alan Petrik), Noby (Noby Nobloch) and Baze (Milos Bazelides). It is available in two quality: with standart or precision chip cap. Last one is equipped with blue LED. Those who are affraid to order from an ex-socialist country, can order it from Sintech located in Germany.

Was made 20-20 pieces from each series.

In order to eliminate the shortcomings of original DivIDE, the Polish Jarek Adamski and Jurek Dudek constructed the DiwIDE interface.

Although the original developers of the card were upset, they agreed in the fact, that DivIDE needs further improvements. Mainly it was necessary to enlarge the memory to fit inside the more complex operating systems.

DiwIDE v212 was the first public testversion. It was contain 32K EPROM, 128 or 512K battery backed SRAM. The CF connector was existed as only as an option, but the Sinclair thoroughgoing connector was already integrated by Jarek.

DiwIDE v317 or alternatively DivIDE Plus was the final release. Contains 512K ROM and 512K RAM onboard and has DivIDE and MB-02+ compatible modes. Also integrated a Compact Flash connector by default. The card incorporates six operating systems: the original FATware, ResiDOS, +DivIDE, DEFMIR, MDOS3 and TBIOS. In the future expected the support of CP/M and ZXVGS. Minimum exits in two subgenerations: as a green and a red coloured PCB.

The interface is sold by the English RWAP Software with DivIDE Plus name.

The upgrade of Velesoft, DivIDE 512 contains 512K SRAM and 128K ROM. It works with SD card as default (by an IDE/SD adapter) Additionally, the whole stuff is boxed onto a neat black plastic case. Have two modes: a DivIDE compatible, and the 'allram' mode, which is similar to the R"GAL tuning. RAM also can be write-protected. For realization the original 28 pin chip-mounting have to be replaced with a 32 pin one. Noby also helped in its creation. Release date: 2008. July 09.

DivMMC an open standard. It was developed by the Italian Mario Prato, from who we can know about the Chrome clone. Main features are the dual SD card connector, NMI and optionally a reset button and 128K Flash ROM, which can be easily expanded to 512K. In 2013 saw the light. Its name comes from joining Divide and ZXMMC +, indicating, that with both are compatible.

The Dutch Ben Versteeg was also produced Divide 57c. His current development is the DivMMC Enjoy! (2014) interface. This the further development of Prato's work with a Kempston joystick compatible interface. It has one piece SD card reader. Instead of Flash ROM, received 128K of RAM, which can also be easily expanded also to 512K.

The Polish Piotr Bugaj's (Zaxon) cards is based on this too. First got the simple DivMMC name. MicroSD, 8K ROM, 512K RAM, NMI and reset are the main features. The missing Kempston port can be added with a mini-port expansion card or can be connectd through the edge connector with a Kempston joy interface. PicoDivSD is the minimalist version of it, without expansion port, edge connector and reset. It is preferred to use with the post-128K Spectrums, since they have factory joy port and reset button. Next one is DivSD Nano, which a bit bigger compared to pico, so more easy to de-attach from the 128K Spectrum. The reset was also fitted again.

The Polish Lotharek also offered DivIDE 57c clones. The first bunch from 2009 is red, the second series of 57c clone is purple from 2010. His own development is the DivIDE 2k11 (DivIDE 57c2?). This is fully compatible with 57c, but due to the CPLD, further (firmware) expansions are possible. As it is a newer design, the card is also smaller size compared to the original. DivIDE 2k14 (or alternatively DivIDE 57c3) also CPLD based and differs from its predecessor from a joystick port. It can be configured as Kempston or Sinclair. Has place for four flashable firmwares and power consumption also reduced by using SMD components.

Ewgeny7 used as a starting point the DivIDE 57c to develop the Russain-clone compatible MultiIDE. This has already a ZX-Bus connector. The most important innovation is the Flash memory module, in which simultaneously 8 operating system can be placed in. Selection from them is done by jumpers. Who want to order, can do it through zst's homepage, he will send his usual blue coloured expansion card.

The DivIDE 57d series from 2012 is the result of Czech-Brazilian co-operation. Victor Trucco was sent his friend's (Alexandre Colella) TK clone to Velesoft to find out the reason of incompatibility. Only in two places had to change interface. The pin 4 (Sound in) only have to be deactivated, so to be cut through. The number 16 one (Mreq) have to lift up, and connect a thoroughgoing resistor. Rui Picanco was suggested to enhance the modding with to be made switchable the pin 4 with a jumper, since it uses the ROM1OE signal in the case of post-128K+2 Spectrums.

So after the modding of original 57c, they made three series in which with a jumper can be set the TK-compatible mode. There are several subversions: 57d blue for Brazilian users, 57d2 green for Czech colleagues, and purple 57d3 for the members of World of Spectrum forum. Other improvements include: signal strength, and ZX and IDE reset button. The HDD AC power connector has been replaced with the connector of IDE adapters.

Later Velesoft was further developed these also with 57d4 name. It got better bus signal booster. 57d3 got a new joystick interface PCB also.

On the summer of 2014 the RTC module for DivIDE was born again from Velesoft. It is compatible with 57b, c, d1, d2 and d3 cards. With the RTC72421A or RTC72421B chips it handles the time attribute of files under the ESXDOS operating system with FAT16 and 32 file systems. Of course, it needs an CR1620 battery to do this. It contains a double output multi-functional Kempston joystick port, to which the mouse of Commorodre 64 and Amiga could connected, as well the controller pad of 8 and 16 Sega consoles. It can be also used as bi-directional serial communication port. It is possible to use the original 8K EEPROM, and 4 different operating system. We can choose among them from the 32K AT28C256 EEPROM. For installing the card, need to be plug it into the socket of M-GAL and original EEPROM chips, and after put these chips back onto the PCB.

DivIDE is compatible with all ATA devices including HDDs, CDs/DVDs and CF cards (the last option is the most popular among the users).

Data transfer speed is 218K/sec and the full capacity of ATA devices useable. Compatible with all Spectrum variants and clones.

Let's see the operating systems of DivIDE. FATware is the development of Baze. Supports eight FAT16 partitions with long filenames. It handles TAP, SNA, Z80 as well normal and interlaced SCR files. It reads on the fly the files copied on a PC to the Compact Flash card when it is plugged into the DivIDE. Unfortunately, can not write onto it, this feature was planned, but seems unfinished. Last official version is v0.14 from 2011. Several patches are exists, Velesoft and (Micky) Michal Tarasiejski made them with the agreement of the author.

ESXDOS is the firmware of Papaya Dezign. It is the work of LaesQ, L.A.Esq, who’s real name is Neil Laws (Great Britain) and Phoenix (Portugal). Has full support of FAT 16/32 file systems without extended partitions, long file names and 64K cluster support (they are planned). In case of DivIDE, supports HDD/CDROM/ZIP/LS120, for DivMMC supports MC/SD/SDHC devices. These are controlled by drivers. Also has TR-DOS, +3DOS and cassette emulation. Last official version is ESXDOS 0.8.5. Aside Velesoft, UB880D made patches and add-ons for it.

DEMFIR (DTP's Emulator Files Runner) is using the ISO 9660 file system of CD-ROMs with long file names. Beside of real discs also can handle their ISO image files. It detecting the IDE devices, then automatically boots from CD-ROM. In case of other IDE devices, if there is an ISO file at the beginning of the medium, it can automatically load it, otherwise should start manual search. TAP, TZX, SNA, Z80, MFC, SCR and POK files are supported, of course only can read them, not able to write. Last version is d0.7b, which was released on JHcon 2006 party. Meanwhile Velesoft and Zilog modified it. Responsibles of the project: Michal Jurica (Mike/ZT, mikezt), Tritol and UB880D.

For the latter two operating systems appeared z00m’s DISO image file (utilities?). But the ESXDOS one is only a reduced version.

For to the ex-Didaktik owners was born the MDOS3. It uses virtual D40/D80 disc images, and can handle total of 4 of them. It is the development of CI5 the amateurs team, which was also introduced the MD3 file extension at the same time (virtual disks). Capable of emulating the tape recorder also. Coders: Sweet and MTs, English-language document translation: Jakub Chalupnik, Logout and mikezt. Latest version from 2010. There is also exists an MDOS3 tool suite, this was created by Dizzy between 2005 and 2007. As a continuation, released the MDOS TOOLS - Project 2 and Project 3, which work is from 2010 by MTs.

MDOS 2.1 is a ROM modding for Didaktik Kompakts, using the same MD3 extension. Was made by MTs.

+DivIDE is the adaptation of the GDOS/G+DOS operating systems found in DISCiPLE and +D disk interfaces, the work of the Dutch Rudy Biesma from 2005. Compatible with all software, which are not using the GDOS/G+DOS ROM calls directly. Uses 1600 sector disks on IDE devices in LBA mode (800 Kb, 2 sides, 80 tracks, 10 sectors and 512 bytes per tracks).

Scott-Falk Hühn was released the +divide Manager Windows-based program, with which can manipulate the virtual disks via graphical interface in an easy way.

BS-DOS 3.09 is the update of BS-DOS 3.08 operating system made for MB-02+ by Busy. It using 2 megabytes of virtual floppy disks, from which maximum 255 pieces can be used (MBD files). The old floppy BIOS was updated with an IDE BIOS. Was born more versions, later ones are bugfixed and supporting the NMI function (August 2009). Beside Busy, name of Dusky is worth to mention, since he was coding the IDE BIOS. And Z00m was created its installer. Only compatible with old R”GAL modded DivIDE interfaces, but also supports the allram mode.

Two new BIOSes were also published. TBIOS basically a hardware testing suite, useful for those, who like tinkering and for example build the interface for themselves. The source code is available, in order that the developers understand how handled the ATA interface, the shadow ROM etc. Final version is v1.4 from 2003 and the work of Zilog.

Velesoft BIOS is a new BIOS for the interfaces from 2011. After downloading the appropriate files, needs to be re-burned the EEPROM. Capable of handling 2 megabytes of virtual memory with boot menu. This is quite large space enough for many things. Also compatible with DivIDE Plus version.

Goldfinch (Gasware) is an aborted project from Gasman (Matt Westcott). Last time it was updated in September 2008. This contains an .scr viewer and writer as well a .tap and reader and writer. For accessing FAT16 file system uses Garry Lancaster’s FATfs system from ResiDOS. Low-level DivIDE ruotines are derived from Fatware. The system is using Paul van der Laan’s Clairsys font, which is a modified of the original one with some enhancements. Its size is only 6 kilobytes, half of this is code and half is empty buffer, so in theory it could been even firmware.

Garry Lancaster’s ResiDOS operating system also supports DivIDE+ and Velesoft’s DivIDE 512 card.

Velesoft also began writing of the quite funny called TRD-OS operating system, which he was eventually stopped. Participated in this 2008 development Hood (Milan Stava) as well.

What we can know about it, that based on the operating systems of MB-02+ BS-DOS and Profi clone, and can handle four virtual disks up to 1 megabytes. Source codes are still there ...

Updated: 2016. October

ZX-IDE internal
ZX-IDE external
DivIDE 57c
DivIDE Plus
DivMMC (by Prato)
DivMMC EnJoy!
DivMMC (by Zaxon)
DivIDE 2k14
TK compatible modding of DivIDE 57c v1
TK compatible modding of DivIDE 57c v2
DivIDE 57d
DivIDE 57d2
DivIDE 57d3
Joystick module for DivIDE 57d3
RTC module for DivIDE 57x

Megadrive 256

Megadrive 256 v1.0

Tnt23's (Tim Tashpulatov) SD card floppy emulator is named Megadrive 256. Amiga owners also know as Amiga Floppy Emulator. This is only partially covers the reality, as also compatible with ZX/TR-DOS, Atari ST, and MSX disks.

The prototype (…) was followed by the yellow coloured PCB Megadrive 128. Then the 'green' Megadrive 256 v1.0 and v1.1 was released.

The card could get fancy green, white or yellow coloured LCD, and floppy sound is simulated by a mini piezo speaker. The onboard memory is represented by an antique 4/8 megabytes SIMM module, here will be loaded the floppy image files from SD card.

It takes approximately 15-20 seconds, for the compresses formats (for example Atari ST) this time is increased by the unpacking time. In case of TR-DOS disks, this time is 16 seconds. We can navigate in the menus of alphanumerical display with five buttons.

About the mass storage devices: SD cards supporting the FAT32 file system, tnt23 tested maximum 2Gb ones (long file names and using of subdirectories are supported).

The IDE connector is 'officially not supported'. Although the designer tested it some old CF cards and HDDs, decided not to focus on IDE functions (therefore not ever card has the IDE connector soldered).

HcX Floppy Emulator

France Poland

USB HxC Floppy Emulator

The idea of HxC Floppy Emulator appeared on early 2006. Jean-Francois Del Nero (jfdn, Jeff, HxC, HxC2001) as an Amiga and Atari ST fan would like to use his old machines, but without the old, annoying floppies. Then was born the first prototype of HxC, which is connected via the parallel port to a PC. On the 'another end of the line' was the 34 pin floppy connector of the Amiga or Atari. Between them the TTL-based converting device, the emulator card.

On 2006. December 08. saw the light the enhanced version, which is built around the Altera CPLD, and the parallel socket was changed to an USB 1.1 one. Hence its name is: USB HxC Floppy Emulator. The PCB is available in two versions: Rev B is a homebrew one, and Rev C is a professional, two-layer construction.

Among the classical micros, usable on ZX Spectrum +3/+2A/B computers. It handles the .DSK, extended .DSK format (read-only, special image file). The best thing is the support of .TRD and .SCL files, so new Russian programs will run on a traditional micro.

On 2007. April 05. was born the HxC Floppy Emulator SDCard FGPA-based prototype.

Then, on 2007. December 22., the SDCard HxC Floppy Emulator, built with the PIC18F MCU and alphanumerical display, which is Jean's last development. This supports SD cards up to 2Gb and SDHC cards up to 32Gb with about 500K/sec data transfer speed.

Using the FAT32 file system, support of long file names and subdirectory structure is also solved. Anyway, the same disk image formats are supported as in the case of USB version.

The professional quality version of this interface manufactured by the Polish Lotharek since 2010 March 13., which is made on his usual, red-coloured PCBs. It has detachable display, 3 LEDs and 3 buttons (next, back, eject) and a small speaker. Otherwise, the USB-version also can be ordered from him, and from several (independent) producers also distributing the USB-version.

Weblink: HIÁNYZIK!!!!! Galéria:
SDCard HxC
USB HxC by Lotharek
SDCard HxC by Lotharek


The ZXMMC interface was born during the development of ZX-Badaloc clone, so its father is the same Alessandro Poppi, whom we met there. This is an SD/MMC card interface, which is placed into the Z80 slot. Originally was designed for the Amstrad produced Spectrums. In theory, compatible with all Spectrum, but inserting suffers physical limitations. In fact, can compatible with any Z80-based machine.

Baud rate is 218KB/sec, similar to Divide because of hardware and software limitations. Supports two memory cards, but in case of the basic version, only soldered a single socket.

The basic version was built with the Xilinx CPLD XC9536XL. The full version with the XC9572XL, and Kempston joystick and RS-232 ports were also integrated into it. In any case, it can be retrofitted for the basic model as a separate circuit called SerialSucker.

Its further development the similarly Xilinx XC9572XL based ZXMMC+, which offers Interface I compatible network capability, just like the RS-232 section. Got 512K battery backed RAM, and the same amount of FlashROM.

This one is compatible with all Spectrums, as it have to be connected to the edge connector, and itself also contains such thoroughgoing port. NMI and reset buttons were also seating next to the dual card slot.

Pino Giaquinto was also designed an USB adapater card, replacing the RS-232 port. It can be useful nowadays, as the new PCs usually do not have serial port. The mini-circuit must be plugged into the place of original serial port, fully fits into it. Includes only two pieces of ICs, their operating is indicated by two LEDs. On the enhanced, Issue 1a board only changed the place of components.

In both cases, can be used the ResiDOS as operating system. For ZXMMC, the version made for ZX-Badaloc should be used. The plus one has a separate version available.

USB Interface for ZXMMC+

ZX Dandanator! Mini Spain

ZX Dandanator! Mini is an 512K EEPROM cartridge, the creation of the Spanish Dandare. Its aim was to create a peripheral device, which helps the console-like game development. In addition, of course, it supports 48K and 128K compressed and uncompressed .Z80, .SNA and 48K .TAP files and using of alternative (for example test) ROMs. Was born from the developments of Antonio Villena.

Its additional features the poke/trainer with .POK files, software compression, screen pause and Ramjet 3 emulation. Through the Spectrum EAR connector, a serial port or DivIDE-like card can be loaded the programs into it.

Key features are the 512K memory, which allows the use of multilevel loading programs, turning into a video console the Spectrum. Starting from 2.0 version contains a Kempston joystick port too. Compatible with all members of the ZX Spectrum series, in addition also with Harlequin, Timex Sinclair 2048/2068, the TK90/95, Invest Spectrum and Just Speccy 128 with in the latter case the inner DivSD is deactivated.

It includes a through edge connector, so works great with another devices. On the first hand, can be deactivated without disconnecting, and the other hand, and it can automatically shut down itself, if a peripheral using the ROM address.

Capabilities of the card is demonstrated in the Ianna Sword game.

The project was started in March 2016, with the in collaboration of Spanish Speccy community. In May was completed, and in the next month was ready for posting the first version of the card, component, boxing combo. After another month, the second version was also born.

All documents are public domain, so anyone can build it freely, but can also be ordered through the author's website - in this case, of course, it is expected some turnaround time as well.

Updated: 2017. January

ZX Dandanator! Mini v1.0
ZX Dandanator! Mini v2.0

Interface 1bis South Africa
Dan Antohi has been developing his Interface 1bis card in South Africa since 1994, so it is reaches the Version 4b number now. It is (backward) compatible with the Interface 1 at the level of Microdrive commands. The RS-232 and ZX-Net was not fully implemented, as they have quite limited possibilities and became obsolete during the years.

The 'M' drive can be a maximum 128Gb capacity SD card split into 32 megabyte partitions. Also there is a possibility to connect it to a PC through an USB port and we can use its shared drive as letter 'V'. No maximum size limit is here. These are the possibilities of handling of the .TAP, .Z80 and .SCR files.

On the card clearly visible the nearly two decades long development. Its main features the double layer PCB with CPLD, and the very robust, overbuilt finalization.

It also has Kempston Joystick and PS/2 mouse ports. The last can be Kempston mouse or Joystick compatible.

First version (Version 1a) saw the light in 1994. This was a expansible card with four fully buffered expansion slots.

The whole thing is placed into an Atari Gameselex box, and the card itself was made on an Apple II prototype card. Memory could be 32, 128 or 512K SRAM chips, accessible as maximum three 128K RAMdisk.

It had Centronics and Kempston Joystick ports. The operating system is burnt into the shadow ROM. It emulates the original Interface 1 (of course the previously mentioned ZX-Net and RS-232 excepted), and also contains a 32/64 column printer driver.

Version 1b was appeared four years later. The PIO mode IDE controller was built on a separate ISA XT prototype card. It was introduced the virtual 32 megabytes Microdrive support. Also it was the very first time realization of the client-server connection, of course using the parallel port for connecting the 'V' drive at this time.

In 2002 released an IDE controller for the Z80-based machines, which was crunched into a 36 macrocell CPLD - this was an intermediate step for the further development.

In 2004, with Version 2a, the interface was integrated into a 72 macrocell CPLD, which now was fit into a Multicomp MB3 box, while retaining its full functionality.

Between 2005 and 2008 (Version 2b-2e) was the period of memory optimization (shadow ROM, memory area and puffer).

In year 2009, in the case of Version 2f, five input and output lines replaced the grounding lines. So from this time we can speak about streaming parallel port, which works with 8 input and output, as well 4 control ports for the communication.

Again in 2009 saw the light the Parallel Port peripheral too. This is an MCU-based device, which is connected to the parallel port and gives RS-232, USB 2.0 and 12MHz SPI port support. In the same time, the drivers also written for the device.

After another one year, the support of SD card also realized by the previously mentioned SPI port. At the same time, the file system of SD and HDD was also improved.

Again, in the same year, another module was born, which named to System Bus peripheral. As its name suggests, directly connected to the system bus. Also an MCU-based device, and supports SD-card, USB, Kempston Joystick and Kempston Mouse (PS/2) ports.

Version 2g-i is the fruit of the same year, at this time the above mentioned module was improved.

The next variant from 2011 was Version 3a. At this time, the interface and the winchester together were integrated into a Dk'tronics house. Parallel port was eliminated. Meanwhile, the modern USB and micro-SD card ports integrated. At the same time, the size of the card became more and more compact and got a 'real' power supply instead of the dead Spectrum's power unit.

In 2012 in order to prepare the small number series production, the IDE port was cut off with Version 4a. So now the logic of the card was fitted into a 36 macrocell CPLD.

After a year, with Version 4b, the RAM drive option was also deleted. In that way, only 32K SRAM necessary for the card, and six I/O lines were freed up. The PCB got a voltage regulator circuit, which now measures 100x49,5 mm and it is two layered. The possibilities of the (small) series production now ready, first units were came out in January of 2013.

Interface 1bis version 1b
Interface 1bis version 2i
Paralell Port Peripheral
System Bus Peripheral
Interface 1bis version 3a
Interface 1bis version 4a
Interface 1bis version 4b

Z-Controller Russia

Z-Controller is also King of Evil's inventment, the guy with the Pentagon 1024SL computer. This one is a really universal too: we can connect PS/2 keyboard and mouse, contains an IDE controller for hard disk and CD-ROM as well a Flash Card adapter.

Signals of PC keyboard are converted to standard Spectrum signals with some extras (for example F11: Magic Button, F12: reset). Signals of PS/2 mouse are converted to Kempston Mouse.

Anyway, the IDE controller is developed on the basis of Nemo's card. Empty circuit boards can be ordered for 300 rubles, and made in the Zelenograd factory such as the Pentagon 1024SL with today's standard. Those, who feel enough competent, with the free access documents can make one for themselves.

The developer was testing it on Pentagon 1024SL, Scorpion and certainly with KAY 1024 machines.

Pentagon 1024SL v2.666 already contains this extender integrated onto the mainboard, with some extras, such as USB and VGA ports, as well a real-time clock - as described earlier.

Z-controller v1.0

ZX Multi Card

ZX Multi Card v1

ZX Multi Card is the inventment of the Russian Caro (real name: Kamil Karimov). With help of that device, quite well can enhance the possibilities of the Spectrum.

Through the card, we can attach PS/2 keyboard and mouse, and it is also contains a real time clock.

Signals of PS/2 mouse are automatically converted to Kempston Mouse signals. In addition, this multifunction card also contains a modem. These devices can be tested trough built-in programs with pressing Win, F1, F2 and F3 simultaneously.

With further module enhancements SD/MMC cards as well conventional tapes can be used as storage devices. An another extender contains a MIDI Out port.

Version1.x boards were followed by the v2.x ones, which have bugfixed board. Beside that, some ICs are integrated into a simple circuit.

Again, all documents are freely available.

ZX Multi Card


ProfROM Second Edition

The initial disgusting feature of Scorpion from other clones was the utilities burnt into the ROM. The so-called ’Service Monitor’ first only occu

TBBlue Brazil

Fabio Belavenuto (FB Labs) és Victor Trucco (VTrucco) közös projektje a TBBlue klón. Az ULA sikeres visszafejtését követően vetődött fel az FGPA alapú fejlesztés. Ez jónéhány ZX klónt és perifériát jelent. A 48K-s és 128K-s Spectrum mellett a brazil TK90X, TK95; ZX Spectrum 128K+3e, ZX80, ZX81 és Jupiter Ace konfigurálható.

A DivMMC lett a háttértár, SD kártya és esxDOS támogatással. Ez maximum 8 gigás FAT32 partíciókat kezel. Innét kerül betöltésre a firware ROM és a programok .TAP formátumban.

A hang AY-3-8910 vagy YM2149 emuláció, sztereó jack-en keresztül. A MIC és EAR is külön csatlakozót kaptak.

Két darab joy port is megtalálható, Kempston, Sinclair és Cursor 2-ként konfigurálhatóak. A második portra PS/2 adapter segítségével egér vagy fényceruza is köthető.

A crackerek kedvenc eszköze, a Multiface is integrálásra került One, 128 vagy +3 verzióban működik, éppen az aktuális kiválasztott klóntól függően.

Szabványos PS/2 billentyűzet és VGA csatlakozó is megtalálható rajta. Támogatja az ULAPLus grafikus üzemmódot is.

Végül kétféle 'kiszerelésben' készült el. Fabio dobozba szerelhető változatot képzelt el. Ezzel szemben Victor lapja belepasszintható egy 48K-s Speccy avagy TK90X/95 eredeti házába is. Mindkettőhöz külön kell megvenni az FGPA kiegészítő kártyát (EP2C5T144 Mini). Elbőbbi 2015-ös, utóbbi 2016-ban látott napvilágot.

Hozzáadva: 2016. április

TBBlue by Fabio Belavenuto
pied 16K, but extending its functions, soon reached the 64K limit.

Further utilies (’Professional Extension’) wanted to be load externally from floppy disk, so programs would occupy a portion of RAM. But this would lead to compatibility issues.

That is the reason why Scorpion decided to construct Professional ROM (ProfROM, which is a mini ROM board in 128K and 256K versions. First one can hold 80K of programs, second is capable of 208K. A 512K variant is also exists, which divides the capacity into two 256K parts, we can select them by a switch.

ProfROM has some nice features: compatible with SMUC, able to configure mouse and joystick, fast formatting of floppies, as well contains screen editor and debugger.

ProfROM Second Edition is the design of Witchcraft Creative Group existing 128K or 256K versions. With a jumper not only to Scorpion, but can be connected to KAY and ZXM-Phoenix machines too.

Worth to note, that Velesoft already in 2007 designed his own version. It only exists on ’paper’ at the moment, not tested by even the author yet.

Added: 2010. January 23.

Proface AT

Proface AT PS/2 version

The weak point of Spectrum was the keyboard for a long time.

For solving this problem, quite wide range of devices were born. Still, you can buy interfaces with PC-keyboard connector. So, you don't have to afraid about the keyboard membranes, you can use the cheaper and better quality PC-keyboards.

Proface AT is existing in some versions. It has an internal and an external variant. Internal is suitable for people who want to build their Speccies into a PC-case. Of course, the internal is a bit cheaper too. Velesoft also engineered the PS/2 version.

Resets are going in the same way as on PCs: Ctrl+Alt+Del. Some floppy commands, such as Format, Cat are accessible through the function keys. Certainly, you can use the cursor keys and also the numeric pad. It has some another extra features, but most customers buy the interface only for connecting PC keyboards.

The external Proface also has a thoroughgoing edge connector. Good quality Speccy keyboard stickers are also come along with the interfaces. Sintech, RWAP Software and Kompakt Services are selling it.

IBM PC Keyboard and Mouse Contoller

IBM PC Keyboard and Mouse Controller

Of course, Scorpion company also offers the possibility of connecting PC-keyboards.

Their joint development with D. K. (a firm also located in Saint Petersburg) is an universal XT/AT keyboard and mouse controller. It is compatible not only with Scorpion, but with another ZX Spectrum clones too.

The PC keyboard controller has some smart features. It detects XT/AT keyboards automatically. Also supports both Latin and Cyrillic keyboard layouts.

Common functions of most popular word processors (as TasWord, The Last Word 2, ZX Word) accessible directly from function keys. The same can be said from IS-DOS commands. Pressing Pause button will hang on running the programs, Ctrl+Alt+Del will reset the computer.

The mouse controller is converting the datas of Microsoft Mouse to Kempston mouse, make handling easier of new Russian software. But it also emulates classic Kempston, Cursor and Sinclair joysticks - even with autofire function.

Magic Button can be activated by keypress too.

Worth to note, that not all mouses and keyboards are compatible with the card. For that reason, better to buy it as a complete set (controller, keyboard and mouse). Russians also studying marketing...

The card is sold by Perspective Group too.



The initially in Great Britain grown up, presently living in the USA JROK offers an another solution for replacing the folie membrane of ZX Spectrum. The interface called Yet Another ZX Spectrum AT Keyboard Interface (YAZSAKI) and was born in 2006. The author was only wanted to play with Manic Miner, and see what is the result...

The fairly Japanese sounding interface only consists of two elements: the Xilinx XC9572 programmable logical circuit and the Amtel AVR Attiny45 micro-controller.

Of course, it supports the combined keypresses, so delete and cursor keys are useable among others.

The sample of printed circuit board, as well the driver software are downloadable from the website.

ZX Spectrum USB Keyboard Conversion

ZX Spectrum USB Keyboard Conversion prototype

Lee and LanceR, two friends made an interface with ZX Spectrum USB Keyboard Conversion name.

So from that easy to guess, that it is an interface for attaching USB PC-keyboard for the Spectrum.

After solving the construction of the original folie-matrix, they modified an old 18f4550 card of LanceR. After it was worked fine, they replaced it with a more good-looking PCB.

Hozzáadva: 2011. October 22.

Covox and Soundrive Russia Czech Republic
Soundrive Monster

Probably most of you remember to the "poor man's soundcard" of early '90s - that was Covox. Some "scientific" names of the device: Covox Speech Thing or sometimes Covox Plug.

This is a simple digital to analogue converter attached to the parallel port. The signal can be boosted with hi-fi equipments, so both digitised effects and music can produced in quite good quality. Covoxes have some different versions beginning from IC variants to resistor type ones.

Covoxes had stereo and quadro versions also. First one is consist of two mono Covoxes, second is integrating four Covoxes into a small board (name of this device was Quadrofonic DAC).

Ready-made Covoxes were also commercially available named to Disney Sound Source. With decreasing the price of soundcards, Covoxes became less and less important - at least in the PC-world.

Among 8 bit home micros, Covox is widespread still (for example Atari XL, Spectrum, but the excellent products of Russian industry, Elektronika BK and Vector were also enhanced with Covox.). This was supposedly facilitated by the fact, that the AY-8910/12 and YM2148F sound chips did not have Russian analogues. Mono versions are existing, as well stereos. And Pentagon Covoxes a little different from the Scorpion's devices.

Quadro Covoxes named Soundrive (one "d!"). Just as at the PCs, four D/A converters integrated to a small board. First version was engineered by Flash Inc. from Novisibirsk in 1995. It has some different versions as Soundrive Normal, Soundrive Baby and Soundrive Monster. Covox and Soundrive were rather popular among users,who wanted to produce digital effects from the ZX Spectrum.

Versions are also become numerous such as 1.01., 1.02, 1.05, 1.50 and 1.51. Of course, Soundrive is Covox and Stereo Covox compatible.

Version 1.02 has 9 chips and in the Russian circumstances contained quite expensive and hardly obtainable elements.

Version 1.05 is made from cheaper and more widespread parts and can be made Covox compatible by a switch. Number of chips were reduced to 5.

Version 1.51 selects automatically Covox mode, if the program does not support Soundrive. Its schematics published in Flash Times diskzine in 1997.

Its modern age reincarnation is called Soundrive TLC7528C. This one is designed by solegstar in 2011, and it was announced on the zx.pk.ru forum as an usual habit with the new Russian devices. It is based on the TLC7258C dual channel D/A converter, from which needs two pieces. The card is ZX Bus compatible, Caro was helped in its creation. It also contains an AY-input to make possible the mixing. First, he made a prototype with PC Centronics plug. In theory, it is works with one piece TLC7225 DAC too, but the developer did not tested it yet. Fully compatible with 1.51 both on software and hardware levels and also with the Profi clone.

Covox and Soundrive's quality is 8 bit. In case of Covox the CPU must divide the signals in time-sharing system to the only port (1x8 bit) or at Stereo Covoxes to two ports (2x8 bit). Soundrive signals can directly ported to each channels (4x8 bit).

Russian games and sound softwares are using the different Covoxes. Greatest disadvantage of the devices, that producing music is completely done by the central processor.

Maximum quality is 10 kHz (with optimisation 12 kHz), if samples and volumes stored in high memory area. If the standard, low memory contains the music, then 15 kHz (or 16 kHz) could be reached.

Special Soundrive music editors: Digital Studio, Extreme Tracker, Flash Tracker, Ultrasonic and SQ Tracker.

Although in much less quantity, but in the territory of ex-Czechoslovakian Republic, Covox and Soundrive were also popular. These were home-made products since the second half of 90's, official manufacturers or distributors did not existed.

Their common points, not connected directly to the machines, but through the UR-4 parallel port interface. Among others, Petr Simandl and Cygnus also published their circuit diagrams on their websites. Last one is on Bytefest 2007 party introduced for publicity the techically quite outdated, but surprisingly good quality converter with the ZN427 chip.

Updated: 2015. May 16.

ABC/ACB/CAB sztereó


Stereo music is invented by the Czech Spec-chums, who soldered some condensers and resistors to the AY-chip and getting stereo music in this way. The tuning can be connected to Busy and Noro. Petr Simandl was also published such diagram. This method was also popular in the territory of ex-Soviet Union and in smaller extents in Poland and in Romania too.

Although seems easy to make this modification, the AY-chip is very heat-sensible. So very easy to burn out the chip with soldering. Better to ask a more practised friend to realise this enhancement. Anyway your Spectrum will not music in stereo - in fact it will not music at all... Some DIY-sites are strongly recommending, not to heat directly the AY-chip, but better to soldering a separate chip socket.

ABC, ACB and CAB stereo modes referring to the orders of channel sequence. The AY-chip (as well the YM of course) has 3 different mono channels (A, B and C). These three channels are separated, and the channels marked with the two winger letters are sounding from the left and right speakers with full loudness. Centre channel is sounds from each speakers with half loudness. ACB stereo is the tuning of the Czech/Slovakian areas. ABC and BAC stereo was widespread in the territory of ex-Soviet Union.

The stereo sound not very difficult to take out to a hi-fi system, so not necessary to hear it from TV. By the way, AY-chip is capable to play digitised sound, although originally it is an undocumented feature. It is very CPU intensive task, and quailty does not reach 5 bit. Newer Russian games are fulfilled with digitised effects.

Stereo music is also becoming standard on most demo-compos.

For the 48K Speccies later appared the AY-chip interfaces, which had uncountable variants during the years. It has to modify a bit the 48K software to work properly with these enhancements -in that case, if they were not made to compatible originally. As before 1995 were not widespread the 128K machines in the ex-Czechoslovakian Republic, many games had been converted to 48K. Of course, our Czech friends tried to write 48K+AY compatible games.

At present, Melodik interface sold by Kompakt Services is the only one such commercial interface. It contains a built-in mono loudspeaker, but certainly can connected to the hi-fi equipment through a stereo 3,5 jack in ACB stereo.

Jarek Adamski's Yamod.AYLPT and Sami Vehmaa's ZXAY cards will described fully later.

Not belonging strictly to the topic, but worth to mention, that for some ex-Soviet clones was attached the stereo-tuned AY-chip through the bus system very similarly to the PC soundcards. The best example is the already mentioned Contact CPS-128. At the early Pentagons, into the socket of Z80 processor have to plug a small circuit which contained both the Z80 and AY chips - as we could read before.


Zaxon AY-Magic

Zaxon's AY-Magic soundcard is the usual AY-interface for the ZX Spectrum. Fully compatible with the 128K Spectrum and beside its rubber-keyed mates and 48K+, also works fine with the clones. Theoretically, can be used with all variants of 128K, 128K+2 and 128K+3, but uses the same port, as the original chip, so it have not much sense (emulation of further described Turbo Sound will not work). Has a through connector and a jack socket.

According to the text in the PCB, Yerzmey also helped in its development.

Anyway, Zaxon also develops various interfaces for the C64 and Atari 8/16 bit machines.

Added: 2010. February 21.

Turbo Sound Russia Czech Republic Poland

For those, who thought, the possibilities are ended with stereo-tuning and playing digitised effects with the AY/YM chips - they simple aren't right. The ancestor of 6 channel Turbo Sound (with two AY/YM chips) was existed in the SAM Coupe computer, although this task was integrated into a single Philips SAA1099 chip. Some sources from late 80's mentioned about similar developments for the original ZX Spectrum. Russians call this enhancement to Turbo Sound, Turbo AY or simply TS. Sources are speaking about it as the original development of Himik ZxZ (Himik, Ilya Kudryavtsev), the member of Power of Sound group, and later more anothers were further developed it.

Sadly nor each method compatible with others, except Velesoft's card. Let's see them step by step!

So, the POS-turbo (from 1995) is the creation of the Power of Sound group. Previously they made the TR-DOS version 6.1x (more exactly they cracked it...), as it was written at the Beta-128 section. Their modification is also a second AY with different port. They developed different interfaces for the original Spectrum, Pentagon and Profi. The group was released Turbo Sound Editor, other programs do not support this enhancement.

Pseudo-turbo mode is using the default port and a second AY-chip. The two chips are controlled by some phase-step delay from the same port.

Quadro-turbo (or Quadro-AY and in Russian: Kvadrapristavka) is a typical Pentagon modification: just put a second AY beside the original with different addressing port. Because one AY can sound in stereo, with two can produce quadro sound. This extended version saw the light in 1997 by Rush and Amazing Software Making. Unfortunately no programs are supporting this.

Turbo Sound was also the name of NedoPC team's first implementation. It was only made in small quantities, but the circuit diagrams and documentations are freely available.

The card contains the two AY-chips, and through an IDE cable can be inserted into the original place of AY. Its creators: Victor Roscupko (Ronin) és Roman Valerevic Cunin (CHRV). In 2005 was came out.

Three revisions made. Revision A was the first experimental model, the card has no protective coating. Revision B contains the fixes of the previous and coating was made on it. The Revision C can easily be converted to quadro sound a well

The aforementioned Turbo Sound Editor and Pro Tracker supports it.

Its successor, the TurboSound FM (TFM, TSFM), which is fully compatible with the previous. In addition, it supports the FM synthesis of Sega Genesis.

Two YM2203 chips sits on it. They are compatible with the AY and in addition including 3-channels FM synthesizer. As in the case of ordinary TS, it can be connected to the original place of AY. The system is controlled by a CPLD and two DACs also can be found in it.

It is made in three versions too. Revision A is the 'trial' version, again without coating. Bug fixes were introduced in Revision B (in which a wiring error is still remains). Coating was still missed. The final, Revision C, has been awarded the mask protection and the possibility to lock the FM part as well. In addition, it also received a filter component, and can be controlled the AY and FM parts. This is of course induced a firmware update.

The responsibles of development Vadim Akimov (LVD), Vasily Klimov (JTN) and CHRV, the release date also 2005.

The Czech VeleSoft (Jiri Veleba) also made his own versions. First got the Turbo Sound Easy name, and it contains only one AY/YM chip (all other versions two), as the card uses the internal chip of the computer. Also built in a Philips SAA10999 chip for emulating SAM Coupe sounds. So alltogether 12 channels sound we got. It is fully compatible with NedoPC's devices, and also with SAM Coupe.

For this was made the Sound Mixer for Sound Mixer for Turbo Sound Easy. With this 'easily' can mix the channels of ABC/ACB stereo AY-chip and the similrarly stereo SAA chip with the sound of the beeper.

Also available as complete device as Turbo Sound Easy with mixer.

The standalone soundcard was realized later without the SAA as Turbo Sound Mini. Mini refers to it size in this case.

The ZXM-Soundcard is the development of the Russian Mick (Mikhail Tarasov). The card is capable to play six channel music with 2xYM2203 as well with a Philips SAA1099. The AY/YM part is TurboSound FM (TSFM) compatible, the SAA1099 is with the SAM Coupe. Of course, with special software all 12 channels are available.

The first revision (revision 01) is compatible with the Nemo-bused ZXM-Phoenix and KAY-256/1024, and made in 5 pieces batch in 2010.

The development of the second serie (revision 02) was begin in the summer of 2010. It was born, because the fans wanted to listen its music on real clones, not only on emulator. And it was ready for the summer of 2010 in 'slim' construction which was due to the SMD components. As the card was slim, and had ZX-bus, could use the owners of different clones. Two pieces was made from the second.

The revision was released in the end of 2011. It got three voltage stabilizer. One for the mixer and SAA, and two for the two YMs. So the overheating problem was eliminated. If we do not need the TSFM part, we can block it with a jumper. He was manufactured 10 pieces. The card was used the Amtel ATF1502 controller in the first three revisions.

In the spring of 2013 was raised the question, whenever made new release from the card. Some potential users already had TSFM, and they did not want to 'duplicate' it. After the surveys was born the Light version, which was contained only the SAA part. Worth to mention, that the card become Pentevo/ZX Evolution compatible and got new controlling ports for the SAA, which was made in 21 pieces. The controller CPLD become the Altera EPM7032STC44.

On the basis of this card was made the Soundrive compatible version christened to Middle. Was using the TLC7226CN D/A converter, and made total of two dozens batch.

The final form was the Extreme variant, which development was begin on early 2014. In this, the TSFM part was arrived back, while also kept the Soundrive. The EPM7032STC44 controller was replaced with a bigger capacity EPM7064STC. With this, the reference frequencies become changeable, so can play CPC and ST music also. The last version was made in 38 pieces batch, from which the bugfixed version is named to Extreme rev 01.

The possibilities of the card is demonstrated by three disks, E-Tunes 1, E-Tunes 2 and TS-Play. First shows the possibilities of the SAA, and the last is for the TSFM part (it is the work of AAA, alias Medicament, 3A-Soft, Aleksej Alekseenko and VNN_KCS).

All cards have Line In/Out and stereo jack. Since revision 03 also two RCAs integrated.

The Polish Zaxon, Piotr Bugaj, the member of Speccy.pl community in 2013 first came out with reproducing NedoPC's Turbo Sound FM card. He was tested them on Timex 2048 computers too, which were widespread in Poland. After the prototypes (FM Magic), numerous cards came out from his hands, in which the type of DACs are YM3014.

Turbo Sound FM got the Masakrator FM name.

As Masakrator FM De Luxe debut in the intellectual heritage of Turbo Sound Easy, and it is virtually the analogue of Mick's ZXM-Sound Card. This is including the SAA, however, not one, but two has YMs (a'la ZXM). Unfortunately, the SAA does not work on Timex machines.

As Pierdalator appeared the card containing only the SAA, so you can get six channels stereo and capable of play SAM Coupe music as well. It is the replica of ZXM-Sound Card Light.

Zaxon's stuff can be bought through the webshop of Sell My Retro.

On the newer demo compos there are separate Turbo Sound category (Chaos Constructions and Di'Halt).

Despite the facts, this enhancement is not so widespreaded, because you have to kill a Spectrum, Atari or Sega to get the necessary chip. And not so many programs supporting 6 channel music.

After all, varying the AY/AM chips' clock frequency can result in better sound quality (1,75MHz, 1,77MHz or 3,5MHz).

Now the first TS music "album" came out too - which is a 640K TR-DOS disk.

Good news for the developers: full documentation of Turbo Sound was released as a book from Alone Coder.

Updated: 2015. October

Turbo Sound Revision A
Turbo Sound Revision C
Turbo Sound FM Revision ?
Turbo Sound FM Revision C
Turbo Sound Easy
Turbo Sound Mini
FM Magic
Masakrator FM de Luxe

General Sound 128/512, NeoGS, ZXM-SoundCard Russia

Anyone can turn his Spectrum or Spectrum-clone into a nearly Amiga quality sound machine in seconds with the General Sound card (abbreviation: GS) - no matter it is a basic 48K or a more advanced 512K model.

This card is the development of X-Trade Group from 1997 (Saint Petersburg), but Scorpion and Nemo also engineered their own versions. It exist at least in two different versions. The first, the older one was attached with a ribbon cable to the mainboard, the newer is directly mounted by an edge connector.

Thank to the complexity of board, home made or cloned GS cards not found on the market. To tell the true, this is the most difficult ZX Spectrum peripheral of the classical Russian ZX Spectrum era.

Certainly, most software does not use the extra capacities of the sound card. But most of newer Russian games, updated version of old classics, music editors and players are supporting it, some of them even autodetecting when the card plugged in.

In the case of old classic games, crackers are dug out the music and effects from the Amiga version, and simply attached them to the Speccy version. The soundcard excellent for editing and play back of Amiga originated .MOD files.

The hearth of GS is a Z80A, B, C or H running at 12MHz, with massive 128 or 512K DRAM. Fairly ironical an extension card, which is more powerful, than the computer itself...

Theoretically, as a coprocessor, can calculate everything independently from the computer's CPU. Even can share its memory with the ZX Spectrum. But this possibility is nearly unused in softwares.

Producing music is completely the task of the card's Z80 CPU, so it doesn't need serious resources from Speccy. When resetting the computer, GS will work further more.

Scorpion was included two disks along with the soundcard fulfilled with games and music.

If you see the GS128 or GS512 sign at a program, it means the support of General Sound card with 128 or 512K RAM.

Sampling rate is 37,5 KHz and has 4 different channels. Some of the sound editors with GS support: RIFF Tracker and Excellent Tracker.

In 2007 the documentation and circuits of the card was public released, so the previously only commercial product was freely available for everyone to production.

So NedoPC Group was developed also the new version of General Sound card, which was introduced on June 2008 on DiHalt 2008 with NeoGS name. Fully compatible with the 512K General Sound card, and has some extended capabilities. In the development was participated LVD (Vadim Akim), CHRV (Chunin Roman), King of Evil (Zhabin Alexei) and JTN (Vasiliy Klimov).

Sales of first devices began at October 2008 and cost of ready-made board is 1.800 rubles, the DIY-kit is 1.500 rubles. At the current moment, have two revisions: Revision A, which never went to sale, and Revision B, the final version with error fixes.

And now the technical details: hearth of the board is a Z84 running either at 10, 12, 20 or 24MHz selectable, has 2 megabytes of RAM and 512K (Flash)ROM. Capable of playing .MP3 and 8 channel .MOD files, even from SD card. Built-in DMA circuit accelerates the data exchange. From the SD card, can play the files independently from the Spectrum, what means, powering off the computer does not influences NeoGS.

Mikhail Tarasov also was created a soundcard, ZXM-GeneralSound. The idea of realizing of the card was appeared on the end of 2013. Its main reason can be said, that Mick wanted to realize a less 'powerful' card than NeoGS. On the other hand, he was found some TLC7528CDW DAC ciruits. So the project was finally realized in 2014.

The processor 18 (firmware v1.00, 1.01) or 12MHz (v2.01) running Z84C0020VEC. The RAM size can be from 512K to 2 megabytes with SRAM. The size of ROM was also increased to 128K, from which the original ROM was placed into the low 32K. The controlling circuit is an Altera EPM7128STC100 CPLD. Stereo output was realized with a 3,5 jack and two RCAs.

In the designing of the hardware was gave help Sergey Sirotenko (Blade) as well Tkachuk Valeria (Black Cat).

General Sound new version
General Sound memory module
NeoGS prototype
NeoGS revision C

SID-Blaster/ZX Russia
SID-Blaster/ZX prototype 04

The SID-Blaster/ZX soundcard is basically a C-64, from which the keyboard and video controller was catted down, and which connects though the Nemo-bus to the Spectrum (clone).

The aim of the development starting from 2011 autumn was to create a soundcard capable of playing SID tunes on the ZX Spectrum.

Developers: Byteman (Alexander Alexandrow) and Prusak (Sergey Bagan) First one is created the basic conception, and made the firmware coding of Motorola 6510. Prusak's area was the hardware development, soldering, debugging and ZX Spectrum software development.

The card is simulating both PAL and NTSC systems, SID 6581 and 8580 soundchips also built-in for better compatibility.

The conception is similar to General Sound card, because this also has its own CPU and BIOS.

Added: 2012. March 31.

DMA Ultra Sound Card

DMA Ultra Sound Card (DMA USC) developed by Witch Craft Creative Group commonly with Aleksei Inozemtsevym in 1999. This Ukrainish novelty is a non-profit inventment, which never planned to push into serial production.

Its schematics are freely available. Thanks to the complexity of card (40 chips), difficulties in attaching to clones, as well to few programs using the possibilities of the it, it does not widespreaded too much. Nevertheless, it becomes fairly well-known due various publications of press and electronic magazines (MSD, Echo, Adventurer and Body). Unlike the more popular General Sound card, it does not have own memory, but using the computer's memory with direct memory access. With that method, opposite of Soundrive, CPU usage is only 15% when playing four-channel music. So theoretically 85 % left for games to run.

Attaching DMA USC card to clones needs high level skills. There are many different ZX Spectrum variants, that is why impossible to connect it without special knowledge. The user's guide deeply explains how to use the card with Pentagon 512K and KAY 1024K clones. From this seems, that recommended the card to attach for machines with minimum 512K memory. Another problem is, in turbo mode the card is unreliable. This could be solved only with a hardly available chip.

Developers of DMA USC adopted a number of music editors for this device. Some examples: Access Player, X-Tracker, Digital Studio, ProDigital Editor.

Miki RS232

Miki RS232 interface bottom view

Miki RS232 interface initially was the inventment of Busysoft. This one is connected through the UR4 interface, and offers standard RS-232C input/output. So it is basically a serial-parallel, parallel-serial converter interface. It is also possible to change data between the ZX and PCs. This circuit was realised with the AT89C2051 chip.

His compatriot, Cygnus also fabricated his own version, which is built around the AT Mega 16 chip. By his oppinion, its reason is more easy programming under Linux.

From the homepages, detailed informations as well some utilies are also available.

Sinclair Serial Interface

Sinclair SIF

The Sinclair Serial Interface (Sinclair SIF) is the development of the Czech Pavel Urbancik. It has three main subversions, the newer ones offering backward compatibility with the oldies. Additionally, new functions were implemented and also got some error corrections comparing to older ones.

The hardware itself a dual channel serial interface, ready to open the door to the ‘real world’. First channel is an usual cabled RS-232C connection, ideal for example to connecting PCs. The another channel is an option to integrate a Wi-Fi or Ethernet component.

The possibilities are practically endless, ftp, text-based www or e-mail clients etc., but almost no software developed.

For 1.000 CSK or 40 Euros can be ordered without the Wi-Fi or Ethernet module.

Hozzáadva: 2009. december 22.

Pokeador Automatico

Pokeador Automatico interface top view

Fernando Fdez was published in 2005 the documents, which are necessary to rebuild the Pokeador Automatico interface as well the utilies, which are working with this hardware.

This one is a Spanish inventment, with which you can enter POKEs in the games as cheatings - presumably as the name suggests.

Reconstruction was prohibited by the fact, that documents were released in three different issues (Microhobby 117-118-119).

On the homepage, we can found the relevant three issues, the printed circuit board (which was redesigned by Fernando a bit) and the utilies. Original parts are also listed, and some recommendations to replace them with more common and cheap items.

SpeccyBoot Sweden

Patrick Persson successfully solved the booting of ZX Spectrum over on Ethernet network. The pack, which consist of hardware and software parts (both for the network PC and Spectrum) got the SpeccyBoot name.

This method was originally designed for diskless workstations for booting over a local network. SpeccyBoot is works in a similar way.

The machine gets an IP address over DHCP or BOOTP, then starts a file from the TFTP server (snapshots.lst), which is the list of the snapshots. Then from this list we can choose the right snapshot, we would like to run.

In case of Spectrum, pressing Caps Shift during the 'boot' loads the normal BASIC if the SpeccyBoot is connected. Or this can be equally achieved when closing jumper 1, which disables the EEPROM.

The card is made with the MicroChip ENC28J60 Ethernet Controller. The author used the Olimex ENC28J60 -H development board, which is contains the previous chip. The price of SpeccyBoot is around 20 Euros with some another additional accessories in this case. If we do not use the whole development board, only the chip with its accessories, the final price is cut down to 10 Euros.

After building the hardware, needs to install the software. After compiling the source code, we get a .WAV file, which is need to load into the Spectrum (for example from a mobile phone). Then this program needs to burnt into the EEPROM. Of course, we have to open the previously mentioned jumper.

The card is compatible with 48K/128K/128K+2 machines (maybe also with the 16K ones). Later Amstrad models have different layout edge connector, so without modification will not work (of course, this modification is possible, but Patrick did not have the opportunity to do this). Maybe using Velesoft's ZX Bus protector and +2A/+2B/+3 fixer?

Ik0n was made the version for Didaktik Gama named DGBoot, from which we can read about in the Sindik.at section.

Updated: 2016. March

Olimex ENC28J60-H



With Graphics Memory eXpander card easily "downgradeable" a Scorpion into a Pentagon. Any reasons for that? Well, yes, because the new age games and demos are mostly made for Pentagons, and they don't work properly on Scorps. GMX is soon became the favourite card of demoparties. It's because of faithful Pentagon emulation and it is more reliable and stable like the usually home-made Pentagons.

It emulates 4 another Speccy-variants, including Profi, from which inherited the memory mapping techniques between the 256K and 1M range (backward compatibility). Scorpion says, its reason is, that Profi 1024 is a relatively widespread clone with good software support – especially with end user applications. If we switch off every extra, we get back to the original Spectrum, except of the rubbers keys.

GMX gets some innovative features also. It has 2MByte of RAM, where can be loaded a lot of different things - for example ROMs in order to speed up your Scorp a bit. The card's CPU is a 3,5/7MHz Z80B, can be useful when playing Driller:) The 14MHz version was promised for years, but for now it is sure, nothing will happend with it. Difference between normal and turbo mode approximately is 1,8-1,9x; but with shadowing it is exactly will 2x faster. Some other possibilities of the card are including new graphics modes (for example 640x200) with standard Speccy colours. Also Multicolor capable. The new text mode offers 80x25 characters and can be displayed either on TV, CGA, EGA or VGA monitors.

The biggest problem with the GMX its price. It is equivalent with a complete Scorpion config - so an average user can only dreaming about it.

Kempston Mouse Great Britain Russia Czech Republic Slovakia Netherlands Poland
Kempston Mouse

Kempston Mouse was originally the product of Kempston Micro Electronics Ltd. in 1986. It came along with a special version of Art Studio. As probably everybody knows, the company was famous from its joystick interfaces.

Comparing with its main rival, the AMX Mouse, it works fine with 128K Spectrums also, maybe because of it becomes the standard equipment of ex-Soviet clones. In Europe it never reached wide popularity, despite the fact, it was more superior quality than its rival with the same price, around 70 pounds. Although it went quite popular in the ex-Czechslovakian Republic beside the ex-Soviet Union.

The Russian version was developed independently by two different Spectrum owners nearly at the same time at Saint Petersburg: Maxim Romanov (RML/Create Soft) and Mikhail Kondratiev (MI&DI). The description of first version released in the issue of ZX Format magazine in 1996 December, and the second variant published in the same year's in October in Spectrofon magazine. The Russian Spectrum newsgroup, fido.real.speccy released to public the parameters of scrolling mouse in his e-conference in November 2001. Meantime was appeared the three and four buttons versions. Great advantage of Russian versions using very few CPU resources.

The Czech and Slovakian Kempston Mouse was the development of Kompakt Services from 1994, and Proxima also sold an UR-4 version. In 1999 Hinek Gajda (HG Elektro) released the second version, it can connected directly to the Kempston joystick port. From these seems its basic disadvantage: it is not a real mouse, but rather a joystick compatible solution with the possibility of slowing down the cursor. Anyway, from it also derived its main advantage: works fine with most programmes, as Kempston Joystick is widely supported.

Kempston Mouse Turbo 2006 externalVelesoft also made his own versions primarily the basis of the Russian ones. First version appeared as DIY-kits, and supported only one button. The newer, green colour printed circuit board, named to Kempston Mouse Turbo 2006 has USB and PS/2 ports, and uses the second and third buttons also. Hard to believe, but we can attach two mouses to the Spectrum (with master/slave selection). Also has a video composite output. If it is even not enough, beside the external interface, they developed an internal variant too. They can speed up to 4x the controlling, which can be useful with older, classic arcades.

Kempston Mouse Turbo 2008 is made with new, improved and bugfixed board with Kempston and Fuller joystick support.

Kempston Mouse Turbo 2011 also supports Sinclair joy, as well emulates the keyboard. Now can be connected together two interfaces, again in slave and master mode. The manufacturing and configuring of the interface also became simpler. This version is made by the Dutch Ben Versteeg, who produced and sold earlier K-Mouses. The v2006 and the v2008 upgradable v2006 is made and sold solely by him with user manual and a scroller mouse. The v2011 can be ordered through the webshop of RWAP Software (SellMyRetro).

Most of Russian end user software and some games are supporting Kempston Mouse as standard, and Velesoft converted numerous old programs also.

Jarek Adamski also developed Kempston Mouse compatible interfaces with Yamod.ZXINPUT and Yamod.KMOUSE names. We can read about them right now.

Spectrum Logic Array Module Great Britain

Mark Smith's SLAM project (Spectrum Logic Array Module) is aimed to replace the ULA with using the Xilinx XC95288XL CPLD.

Altogether four versions are planned. SLAM48 and SLAM128 are the standard 48K and 128K versions, SLAM+48 and SLAM+128 are compatible with ULA+. So far, SLAM128 almost finished.

Anyway, all models are compatible with the original ULA according to the tests. Hopefully, as soon as they are completed, it may give a further impetus to the development of modern clones.

Hozzáadva: 2015. December


ZXKit1 VGA&PAL board

Russian Federation

ZX1Kit VGA and PAL board by zst from zx.pk.ru

Development of zst, the ZXKit1 VGA&PAL board is a device for Spectrum and its clones with the purpose to lead out the picture to VGA monitor or TV-set (through S-Video, and RGB composite).

By default, it is compatible with Leningrad, Scorpion, Speccy 2007, Pentagon 48/128, ZXM-Phoenix, ZX-Next and Robik clones. With firmware update, also works with Profi, Orion and Specialist machines.

It has two modes, selection is done by jumpers. First mode is centering the 256x192 Speccy screen on the standart 640x480 VGA (rest of the picture is Border). Second one is ‘upscaling’ the ZX picture to the VGA screen.

Can be ordered as empty PCB, PCB+parts, finished board with standalone VGA or VGA, S-Video and composite output.

Added: 2010. February 26.

Scart RGB to YUV Component Video Converter

United States

Scart RGB to YUV Component Video Converter (from vintagecpu blog

Vitagecpu, who is living in the USA, describes a very interesting viewpoint for the Europeans. As on their TV-sets no Scart input (in full name: Euro-Scart), so standard RGB-Scart cables are useless. It needed a separate Scart-composite adapter also. In case of Amstrad CPC464 it gives black and white picture, while with ZX Spectrum 128K+2 it does not work at all.

The RGB-composite cable works, but the picture quality is far from the perfect (but still more superior than the picture of the RF modulator.)

So vintagecpu bought a Scart RGB-YUV Component Video converter. The 'case studies' on Internet describing half-successful stories. It sometimes works, sometimes not. Maybe you will get colours, maybe not. One of the two tried televisions (NTSC/Pal/Secam multi system) it worked perfectly with razor sharp picture. So we can definitely pick it up among the 'suggested' ZX Spectrum peripherals.

Added: 2011. April 02.

Antonio Villena's extensions Spain

Kartusho V4 is Interface 2 compatible cartridge unit, which includes 512K FlashROM. So, the board which made by the Spanish Antonio Villena can store 32 pieces of 16K and 10 of 48K ones.

The unit is supplied as a kit: with PCB and component combination. Was saw the light at the beginning of 2016 with the price around 10 Euros.

Interface ROM (ifrom) is its further development, but this one is not a ROM cartridge, but a interface connected to the edge connector. Should be noted, that compatible with all variants of 128K machines, you need to set this mode by jumper. Price similar to previous one.

As a further development of this, was born the ZX Dandanator! Mini, which was solved a number of shortcomings: it automatically detects 128K Spectrums and compatible with DivIDE as well.

Updated: 2017. February

Kartusho V4
Interface ROM

Jarek Adamski 's extensions

Yamod.LPTAY Max

The already more times mentioned Polish Jarek Adamski, also offers numerous (or more exactly countless) novelties for the ZX Spectrum. Most of them realized meantime of the Spectrum SE development.

So, let's begin with Yabus.ZX. This one is an interface converter, to which connected into the edge connector of ZX Spectrum, gives the possibility to attach the Yabus devices designed by Jarek into the dual slot.

The prototype of this device was the Yabus.ZXMEM. This would offer three thoroughgoing edge connects and the same quantity of Yabus ports. All above, 32K EPROM and 32K SRAM would built into it. So, we could choose from boot-menu between the different devices (for example MB-02+, +D etc.). The Yabus.ZX due its design, it is much more safe like the Sinclair edge connector, and we do not have to care about the joining sequence. The compatible peripherals gave the Yamod. family name, so we will get know about them.

The Yamod.AYLPT is an AY-3-8910 interface made in two different versions: the basic Med only contains a serial and parallel port above the AY-chip, the more advanced Max got real time clock and has own EPROM also.

The card can work in ZX128 and Timex 2068 compatible modes, even in the mixture of the two. We can attach two cards to the computer in the same time, so one can work in Sinclair, another in Timex mode saving the valuable time of jumpering. In the same way, we can select ABC or ACB stereo with jumper. Thanks to the integrated slot, various peripherals can be attached to it: TC2068 joystick, Keypad or AY-mouse.

The card is useable in a reversed way through the parallel port: we can control the AY-chip with a PC. Some emulators are supporting this method, giving more vivid AY-emulation. In the Spectrum slang, these cards are called LPT-AY interface.

Yamod.ZXINPUT is giving possibility to attach PC keyboard and mouse. Mouse signals converted to Kempston Mouse. Keyboard layout stored in EPROM, so easy to modificate it. Macros also can recorded, and RS-232C port can used for serial communication too. Beside ZX, can used with SAM, Byte, and Elwro.

Yamod.ATBUS is an universal 8 bit IDE interface. Its purpose of using hard disks, CD-ROMs, Zip drives and CF cards with the Spectrum.

Transfer speed is above 200KB/sec. With some tunings can simulate the MB-02+, Interface 1-bis, ZXATASP and Divide interfaces as well Pera Putnik's creatures.

Beside the IDE controller, the board may contain a real time clock also. ZX, Timex, Sam and CPC compatible.

Yabus.IDE8255 realised by the 8255 chip and its aim to control IDE devices. Above the mentioned chip, only one logical circuit needed for building one. The internal 8255 chip of MB-02+ also useable with a special cable. Due to simplicity it is relative slow. The author engineered a CPC version too.

The ZX512 named memory upgrade was made in one and only prototype and designed for the 48K Spectrums and TC2048. This one can expand the memory to 256K or 512K, as well providing ZX128 and Pentagon 512 compatibility. Jarek was also engineered a Multicolor circuit for this device. Going forward in this artcile, will see, that Velesoft already finalized a similar card.

ZX4MB is the succesor of the previous. Only on Issue 6A board was tested. Thanks to the 4 megabytes expansion, this one is also compatible with ZX128 and Pentagon 512. Due to the size of memory, quite complex operating systems would fit into. Also Multicolor compatible. Optionally can used with the FlashD0 extender, which is a 128K PEROM card.

PL3MEM is a memory expander and an IDE interface on the same board. Memory consist of 32K RAM and 64 or 128K EPROM, which basically occupied by the operating system. The IDE interface is the already known Yamod.IDE8255 type. As the name points, it can simulate the work of +3(e) on 48K/128K/128K+2 and TC2048/2068 machines. It is possible to insert a 512K EPROM card into the place of original EPROM, so numerous alternative ROMs can be chosen. The Yamod.IDE8255 can also replaced with Pera Putnik's simple interface.

ZX bus splitter divides the edge connector into three. Some different subversions were engineered. The v004 offers some another sweets: DIP switches for selecting the active ports, reset and NMI buttons, serial port for Kempston joystick, and LEDs giving operational feedback.

With the Yabus.ZXISA card ISA cards can connected to the Speccy. So cheap serial and parallel ports as well floppy controllers can be obtained in this way. Through the HDD controller also we can connect joystick.

Another expanders which worth to mention: Yamod.EPROG is and EPROM burner, but practically useable as parallel interface. A Yamod.KMOUSE and Yamod.KMJOY are Kempston Mouse and Joystick interfaces. A Yamod.EPLIP is a fast parallel interface. A Yamod.PCMOUSE is a simple serial mouse card. A Yamod.SIO was made for radio amateurs: turns TNC modem the Spectrum. Finally, Yamod.ETHERNET a bit expensive Ethernet card.

All cards are can be ordered as DIY kits or ready made.

Miguel Angel Rodriguez Jodar's extensions Spain

The Spanish Miguel Angel Rodriguez Jodar also belongs to the growing mass of active developers

In 2006 developed the Internal PS/2 keyboard adapter for ZX Spectrum+. This is compatible with PS/2 keyboards and also with USB ones with adapter.

His original goal was to reconstruct the 48K+'s damaged keyboard membrane. It seemed to be very difficult, so finally he decided to build the adapter. With this we can record and playback macros, cursor keys are useable as Sinclair joystick and with Ctrl+Alt+Del combination can reset the Spectrum. The PBC can mounted into the empty place near the loudspeaker. The adapter was made a bunch of quantity for some friends. At present, Ben Versteeg is push it into small quantity production. This one is an external, horizontal interface, so fits well to any Spectrums.

For replacing the damaged memory modules was authored the SIMM adapter for lower 16K RAM replacement. Primarily was designed for fitting instead of the usually defected low 16K, but also useable for the upper 32K memory area, and to restoring both 64K banks of the 128K machine. The idea based on a similar MSX project. Using this serice tip was made Alwin Henseler his own version with SRAM chips.

The forthcoming project is still under development. This one is an ultra fast loader, with the purpose of speed up the loading speed from SD cards, CDs etc. Was successfully tested with Flash memory and achieved 180Kb/sec. The idea is based on Codemaster's game compilation CD, which was loaded games within 20-40 seconds.

The next development is already in prototype stage. This is a TMS9929-based MSX compatible video controller board. Its exact name is: MSX Video for ZX Spectrum.

The TMS chip itself is a video controller for general purposes, which is also used in ColecoVision and TI/99 beside the MSXs.

Which advantages can obtained with such a card? We can highly superior the characteristics of the original ULA, as it can control his own 16K video Ram, and the video controller does not uses the resources of the processor. It communicates thought two ports with the CPU, so acts like an external peripheral.

The new graphics modes are the followings: Text: 40x24, monochrome; Screen1: 32x24 chars, 256x192 pixels with sprite support; Screen2: 32x24 chars, 256x192 pixels with 8x1 attributes again with sprite support - this mode is best for quality games; Multicolor: 64x48 big pixels, although each pixels can be different colours.

The card contains the video chip, some DRAMs, a GAL 20V8 circuit. The purpose of GAL to reduce the necessary amount of other circuits, as well is easy to reprogram.

There are some examples about rewriting some MSX programmes of which source codes was given by the Spanish MSX community to the developer.

The card is compatible with all Spectrums.

In 128K and later Spectrums, the Philips TEA 2000 is responsible for RGB to PAL encoding signals from the ULA. This one is very sensitive for electrostatic, and also easily overheating.

After repairing a 128K+2A (Issue 4) all problems were solved, except one. The composite TV-out signal remains black and white. As the TEA is quite rare one, so the idea was raised to replace it with a modern equivalent.

This chip works with 2bits/color data digital signal, one is for the color, second is the 'bright' attribute. So altogether works with 6 bits of digital data. The Analog Devices AD722 – as the most modern RGB-PAL encoders- works with analog RGB signals. So the replacement circuit must simulate this 2x3 bits data stream.

Two prototypes were made from the TEA 2000 replacement daughterboard. In the first, the crystal gives 4,43 MHz by default. In the another, the 74HCT74 IC transforms the 8,8MHz of TEA for 4,43, which is necessary to drive the AD722. All of two PCBs are single sided, and not containing the audio out.

By the way, the developer also publishes in the Zonadepruebas Spanish community site with McLeod_ideafix name.

One of his publications is the +2A/+2B/+3 downgrade to 128K+2. This one is explored, when searched the error in a dead +3. He was though, that the ULA went wrong, meanwhile explored the incompatibility reason of the Sinclair and Amstrad generations. 128K+2 has two pieces of 16K ROMs (ROM0: 48K, ROM1: 128K). In the case of the value of the actual port is 0, then 48K, when it is 1, the 128K ROM loaded in.

Later machines had 2 pieces of 32K ROMs (for +3DOS and CP/M). So Amstrad introduced a new port, the 1FFD for addressing these. Fixing this issue to replace the first 32K ROM with the original 2x16K ones. And it is works flawlessly! The only disadvantage of this method, that +3DOS and CP/M will not work. But solving this, it is an another story.

McLeod also solved the always warming ULA problem. It got a heatsink of a good old 286.

Next tip is the Composite video output for 128K. This one is basically a modification of the 8 pin DIN connector of the 128K Spectrum, which originally was worked as RGB. First step is to direct the unused pin 1 to the mono audio signal. Next one is to convert the black and white signal to colour. For do this, must be solder out the first leg of D34 diode (or cut it - it is more comfortable). Now it is time to detach the audio signal from the video. The C126 condenser must be deactivated, which is mixing the audio and video signals for the TV arieal output. Some soldering, and the cable is ready! Quite interesting, that this cable is fully usable for Dragon 32/64 computers without any modifications.

At last, we can found methods for using VGA monitors also.

First possibility is an approximately 30 Euros Noname RGB-VGA converter from China. This is basically an "industrial" one, we set it once, and ready for use. The disadvantage, is that if we have more retro machines, quite difficult to use. When connecting to the ZX Spectrum 128K +3, it uses the VGA picture after mixing the two half pictures in interlaced mode (we got great areas when mixing black and white.) Refreshing is not so perfect, as frequency of TVs is 50MHz, VGA's is 60MHz or more. But using it with QL, gives a perfect picture.

The another product, which he was tried out, is the DealExtreme converter. This has composite video and S-Video input also. First one is usable for 128K Spectrums, for the second, needs some modifications. The converter has a lot of functions, and can handle the PC and retro picture in PiP system on a VGA monitor.

And all above that, participiated in the development of an FGPA-based clone, named ZX-Uno.

On the OpenCores hobby electronic portal have also a publication, the ULA chip for ZX Spectrum (codename: zx_ula) . It is available in two subvariants. First is an FGPA, second is CPLD version. First has separate I/O bus, so can be a base of different clones. Another one is a "plug and play" ULA replacement, Which can be built into a working clone (such as the Harlequin). Beside, it is successfully simulates the original ULA, also support the Timex HiColor and ULA+ modes. This was integrated into the ZX Spectrum on pipistrello card also.

Upadeted: 2016. March

Internal PS/2 keyboard adapter for ZXS+
SIMM adapter for lower 16K RAM replacement
MSX Video for ZX Spectrum
TEA 2000 replacement daughterboard

Dr. Beep's extensions

ZXPC interface

Ymond Reconstruction Service (YRS) is a Dutch team was founded in the classical times of ZX Spectrum. At the moment, has only one active member, Dr. Beep, alias Johan Koelman.

Dr. Beep's ZXPC interface is connecting the ZX Spectrum with PC through a parallel port. The interface realised with combining two cards: a simple I/O card and an EPROM circuit. With this, . Z80, .SNA. .SCR and .TAP files stored on the PC can be loaded into the Spectrum. In the near future, supporting of .MDR (Microdrive) files is also planned. 48K programmes are loading within 7 seconds.

Dr. Beep is also developing a hardware ZX81 emulator for the ZX Spectrum. This one is realised by a selectable 32K ROM combining both machines' ROM routines.

Sami Vehmaa's extensions

ZXMatrix interface

The Swedish Spectrumist, Sami Vehmaa's developments are quite interesting, as he making continuously the various interfaces, which can expand the possibilities of ZX Spectrum in very different ways.

With the ZXCF, ZXCF+ interfaces, we can use Compact Flash cards as storage devices for the ZX Spectrum. The ancestor was already born in 2003, plus version is the fruit of 2007 year and the +2 upgrade, which is connectable to ZXCF+ was made in 2008.

They driven by the ROMs containing ResiDOS, which we got know about the ZX Spectrum +3e. The card is supports both load and save commands.

His most crispy development is ZXMatrix, which combines ZXCF+2 and ZXUSB cards. Between the two modes we can select with jumper or switch. Main features: 1 megabytes of RAM, USB 2.0 support and high speed CF reading-writing. Vehmaa also made his own version in only one piece. It has 2 megs of RAM and built-in Kempston joystick port.

ZXATASP interface is an earlier development of the author. This is a 16-bit IDE interface with hard disk and Compact Flash card support. The memory can be 128 or 512K. ResiDOS also supporting this device. ResiDOS could be loaded into this memory, so not necessary to rebuild the Spectrum. As the winchester needs an external power supply and the same time of falling down of the prices of CF cards, this card becomes less important.

He was also engineered his own ZXAY interface. It contains the AY-3-8912 chip and suits for 16/48K Spectrums. In the classic era lots of manufacturers and amateurs made similar sound enhancements. This one is sounds in ABC stereo.

The ZXMEM interface is expanding from 512K to the nearly unbelievable 32Mbytes the memory of 16/48K Spectrums.

Vehmma also made a real time clock (with date and time) and a high-speed serial port too.

ZXEXP adapter is an expanding tool, which thorough ZXBUS (the own inventment of the author) could offer the possibility of attaching more interfaces at the same time. All of the author's cards are equipped with ZXBUS. And the last four units only have this expansion system. This ZXBUS of course not the same, as the Russian Nemo-developed standard.

His laptop will be described in a separate section.

Velesoft's extensions

ZY Profi interface

Russians cracked the European ZX Spectrum machines and peripherals, and with adding their own innovations, re-engireed and manufactured them from Russian parts. The Czech Velesoft (Jiri Veleba) recracked these circuits, and built the Russian novelties from European ingredients. In his homepage, beside the 90's development we can faced with the freshest peripherals. Not only for the ZX Spectrum, but also engineering for Sam and Timex Sinclair.

Kempston Mouse (Turbo), Turbo Sound Easy, Sound Mixer for Turbo Sound Easy, Turbo Sound Easy with mixer, Turbo Sound Mini and the PS/2 ported Proface AT were already introduced.

Also was mentioned the developments connected to DivIDE: the DivIDE 512, the DivIDE 57d series, as well the RTC module for DivIDE.

The Data Gear and MB-02 memory interface, which were constructed as the parts of the MB-02+, were already mentioned earlier too.

The Pentagon 512 interface is an internal card for ZX Spectrum 128K+2 (only compatible with Issue 3). The timings of Pentagons are different from the ZX128, in addition, all memory banks and ports are handled as fast ones (Fast IO mode). So programs made specially for Pentagons, are more or less incompatible with the original Spectrums. The interface also solve this problem beside the memory expansion, which is realized with one piece 512K SRAM module. Thanks due to the Pentagon mode, original ZX Spectrum programs are also running faster, which is handful for compressors, image editors etc,

It also contains a 128-512K FlashROM, in which we can store alternative operating systems. This upgrade also supports the Unrain function, and co-operates with the D40/D80 systems. Some of the utility, such as MDOS File Commander and 128Tools using the full memory, so do not have to care too much with changing the discs.

The External 128-512K upgrade for ZX16/48K is similar to the previous, but this one is an external interface made for the 16/48K little brother. In the case of 48K machine, the higher 32K must be removed. The card works with 128 and 512K SRAM modules. When 512K one used, the machine will be compatible with Pentagon 512K and also will be faster than a ZX128. Of course, it is possible to switch off all extras and go back to the ordinary 48K mode. Unfortunately, the expander do not supports the shadow videoRAM, but using of the extra ROMs are possible.

The successor of Pentagon 512 interface is the ZX Profi interface, which gave its name from the similarly named Russian clone. It works only with the Issue 3 grey 128K+2 Spectrum, and its roots going back to 2004. Velesoft refreshed the old project, and fully redesigned the interface.

1 megabytes of RAM, 512K FlashEPROM, a Z80 processor and a battery take place on the single circuit board. ZX Profi 1024, Pentagon 128-1024 and Scorpion ZS 256-1024 compatible. DivIDE, MB-02+, ATM Turbo and Russian cache emulation is under construction.

A ZX 128K ULA clone is also under development. Seems, will be soon built the next Czech superclone...

Hyperface is a new type interface. Contains three ports with direct access, as well one conventional one. Velesoft into his own interface packed a divIDE and Kempston Mouse Turbo interfaces.

In 2007, also designed his own ProfROM clone. It only exists on ’paper’, and did not tested even by the author.

A tiny, but really useful thing is the ZX Bus protector and +2A/+2B/+3 fixer mini card. This can be connected to the Sinclair edge connector. It has double purpose: avoid the data collusion, as well to use the non-standard pinouted 128K+2A/+2B/+3 machines with the old peripherals.

Can be used in multiple configurations. When using the old peripherals with 128K+2A/+2B/+3 machines, must be deactivated the R2 resistor (in this mode compatible with 128K/+2 also). It converts the ROMCS pin of the peripheral into ROM1 OE/ROM2 OE.

If the only purpose to stabilizing the data transfer in the case of 16K/48K/128K/+2 machines, the R2 resistor, D1 and D2 diodes must be eliminated.

Next config is switch off the extended memory and ROM1/2 OE and ROMCS lines, and it is handles the peripherals as a direct port. R1, R14, R15, R16, D1 and D2 ports must removed. It is compatible with all Spectrums. Cand be handy, when using 128K+3e machines with DivIDE interfaces.

Version 2 is the same, but the PCB got better design to attach the peripherals more easily (in case of 128K+2A/+2B and +3 there is small room between the power socket and edge connector).

Version 5 got a jumper in order to get +12V on the +9V port of 128K+2A/+2B és +3 (on the previous version +9V unused).

Updated: 2015. October

Pera Putnik's enhancements Serbia Spain Sweden Czech Republic Italy Slovakia

Pera Putnik is one of the oldest Spectumist, who started his DIY website with various developments in the new age. Primarily mass storage devices are in the centre.

Among the smaller developments, there are various ROM modifications (as external ROM, Flash EPROM and switchable ROM), NMI button, RGB connector, floppy interface (which unfortunately uses its own file format).

He becomes well-known from his IDE interfaces. The simply Pera Putnik IDE interface called device has two variants. First one is 16 bit, the second one is using 8 bit technology. The one and only disadvantage of the 8 bit system, that capacity of hard disk will be half of the nominal. But in the case of ZX Spectrum, this fact is easily ignorable. The teenager developments works fine with modern Flash and Compact Flash cards - last one needs a CF-IDE adapter of course. Transfer speed is around 150K/sec, which is more than enough for Spectrums. ZX Spectrum +3e is also supporting these devices.

Listening to the voices of technology, also engineered his own Compact Flash interface. This is also 8 bit system, and using the full capacity of the cards. Based on the 8 bit IDE interface.

For this section can be connected the ResiDOS operating system developed by Garry Lancaster, and by the 8-bit interface used in ZX Spectrum +3e. Finally, became an universal operating system, that supports a wide range of Spectrum mass storage drive interfaces.

Compatible with Sami Vehmaa’s ZXATASP, ZXCF, ZXCF+, ZXCF+2 interfaces and also with the CF and USB modes of ZXMatrix. Supports DivIDE Plus and Velesoft's DivIDE expansion, the ZXMMC/ZXMMC+ interfaces and ZX-Badaloc clones as well.

In case of MB-02+ interface needs at least 256K RAM expansion and the MB-IDE card too, which is already built into the MB02+IDE. It also works when using standart MB-02+ connected with DivIDE. The own RAMdisk of MB-02+ can not be used in this case, as it would overwrite the OS.

The operating system is basically a Basic expansion, which is using the IDE interface and extra memory of the cards at the same time. Its operation is essentially installing itself into the RAM of the interface along with the modified Spectrum ROM. It contains a complex task manager also, which can be activated with the NMI button.

Installation begins with downloading the appropriate TAP/TZX file for the interface. Have to loaded in the converted real tape format installer into the Spectrum, or in the case of DivIDE+ and Velesoft's expansion, can be started right from the storage disk, then it will overwrite the actual operating system. For upgrading, original tape file is no longer necessary, from any of the interfaces can be loaded the .TAP or .TZX files. Or will you have to use the Basic install part and the card-specific C-language code.

Starting from version 2.00 can handle two kind of partition schemes. First one, the native IDEDOS that is the operating system of ZX Spectrum +3e (includes the original +3DOS too). For FAT16 the FATfs package is required. Using both operating systems simultaneously is also possible. First can handle 16MB partitions, while the latter one is obviously up to 2GB ones. "M" drive is the RAMDisk emulator, that works with both 48K and 128K modes.

Thanks for ZX Badaloc clones, supports the turbo mode, from 3.54 to 42.50MHz, the latter speed rate is still experimental. In the RAM of interfaces alternative ROMs can be stored. Functions of ResiDOS can be upgraded with downloading and installing packages. Latest version also supports SDHC and SDXC cards up to 8GB capacity.

Simple 8 bit IDE interface

Cygnus's enhancements

Czech Republic

PCL printer printing

The Czech Cygnus, alias Pavel Cejka also offering some self developed hardware, which documentation is available on his website.

About his own versioned Miki RS232 interface we could already read.

The ZX IDE Interface is very similar to Pera Putnik's, although the author is suggesting the use of DivIDE interface. Anyway, it works without problems with ZX Spectrum 48/128K+2 and Didaktik Gama 89 machines as well with Beta interface. But it is doesn't like too much the Multiface 128 and Diskface plus interfaces. The available software is in Czech language, and supporting all basic functions.

Also giving some ideas to connecting ZX Spectrum and LCD monitors. On the homepage, there is a detailed description, how to succeed to connect a Spectrum with a Playstation 1 LCD screen. Anyone, who would like to connect any type of LCD monitor to the Spectrum, worth to read to avoid some traps.

A really innovative novelty is the connecting of PCL printers. Spectrumists were dreaming about the possibility of colour printing. But with the exceptions of some colour matrix printers there were no choices. Matrix printers are noisy, printing speed is low, and also the quality is far from the perfect.

As Cygnus is working as a service technician, got positive experience with the PCL language printers, so targeted these ones. He was designed a special Didaktik inverter PCB, to which is connected to a Canon standard parallel port (not Cnetronics, because Canon is more easy to finalize).

Due to the PCL language, all HP printers with LPT port made between 1995 and 2088 will work, but primarily works brilliantly with DeskJet 340. In theory, works fine with the printers of another brands too.

The drivers are supporting the 75-300 dpi resolutions, normal and draft modes, as well setting up the margins.

At last, but not least, we will get some ideas to work with the Aritma 0507 plotter. This is an old Czechoslovakian plotter, which was released in some variants, but they are differing from each others from minor details.

The plotter is connecting through the UR4 interface to the Spectrum. It has two superior technical details, which are better, than its contemporary machines. First, it using 1x8 bits to control all motors, while others are using 3x4 bits for each ones. Another, that it is using the more reliable screw mounting for the pen.

Cygnus was tried the most different printing techniques and sharing them with the publicity. He is printing with the original MZR driver from BASIC, making vector drawings with the Desktop software, and also using the serial port of SIF.

Petr Simandl's extensions Czech Republic

Petr Simandl was begin his computing career with a ZX Spectrum 128K+2A. But not only played games with it, but also designed electronic circuits and making music with it.

Let's begin his hardware development with the +2A/2B floppy interface. It is built around the Intel 8272 floppy controller, and turns a +3 from the above mentioned machine. Anyway, the circuit was originally released in the 1989 December issue of Amaterske Radio. Thanks to its small size it is easily fits into the box of the big Speccy. Philip Mulrane was further developed it as ultimate +2A/2B floppy interface in the form of an external device.

Connecting to the music maker past, was born the 4x8 bit D/A converter based on the Intel 8255 chip. This contains four pieces of 8 bit converters, and as a Covox/Soundrive mutation, capable of playing .MOD files.

Also was born a more simple 1x8 bit AD/DA converter, which he was used with Specdrum.

He made the stereo-tuning of the AY-chip too, we can also found a circuit diagram for it in the website.

+2A/2B floppy interface
4x8 bit D/A converter

Philip Mulrane's extensions Great Britain

Philip Mulrane was reconstructed the already existed floppy interfaces. His first work was a +D clone from 2001. It seemed simple enough to build it according the public diagram on the WOS. Just obtaining two chips could cause problems, the the WD1772 floppy controller and the PAL20L8. You can try the WD 1770, VL1772, WD1791 or WD1793 ones instead of first. The other may be replaced with GAL20V8. Also necessary to obtain the 27C128 EPROM.

The goal was to create such PCB, which has the same dimensions as the original, yet doubles its features. Together with Harald Brunig, using the Protel software the board was ready. After creating two prototypes, they manufactured it with PCBPool company.

After implanting the components, the clone unfortunately did not work. He got an original +D from Peter Rennefeld, the member of Spectrum Profi Club. It was turned out, that the circuit diagram on the WOS was wrong, the address lines of RAM and EPROM was swapped, as well need to use the controller's A3 and A4 lines instead of A0 and A1. After correcting these errors, was born the perfect clone, and on the website, this corrected diagram was published.

Philip was painted his interface to black, which may fits better to the Speccy, than the original white. The 32K +D EPROM utilizes the 8K segment between 24 and 32K. Very probably MGT was bought a bunch of faulty chips, which is work in this region.

In the following year, his another development was also a floppy interface. It is based on Petr Simandl's unit.

He was modified the original PCB and realized in an external form instead of being internal as the original. In addition, he was added Garry Lanchaster's ZX Spectrum +3e HDD interface into it, and this way was created the ultimate +2A/2B floppy interface.

A little modding must be made, if it is used with a single 3,5” drive. The 3” drives has a 'ready' signal, which indicates to the controller, that the floppy drive is ready to send and receive data. In the case of 3,5” units this is mising. Therefore on this drives must be connected the select0 (pin10) and ready (pin34) lines. When using double drives, this is unnecessary, because the signal is always present in one of the drives.

+D clone
Ultimate +2A/2B floppy interface

Paul Farrow's enhancements Great Britain

The English Paul Farrow is best known as a ZX Interface 2 expert in the Spectrum community.

These cartridges are not very well known, so begin this section with some introduction about them.

The 16K ROM cartridges fits into the special slot of Interface 2, was released on the market in September/October of 1983. In a sense, they turn the Speccy into a 'gaming console' - with zero loading time and zero loading error. Despite these positive things, not widespread very much, because 48K games became mass dominant. On the other hand, the loading time of 16K games was much more shorter - so did not worth to switch as an option of the tape. Sinclair Research also released a Test cartridge for diagnostizing the faulty Spectrums, these were used solely by the service centres. The Parker brothers produced some prototype cartridges too, but they were not public released.

Originally, cartridges contained a single 16K ROM (Standart 16K ROM Cartridges - method 1.).

The simple design of cartridges makes it easy to reproduce similar devices. The shortcomings of Interface 2 can be compensated by modifying the 'inner circuits" of the original cartridges. So the 'magical' 16K limit is easily breakable.

One of those facilities, when burning more 16K ROMs into a larger capacity EPROM and then select from them the desired ROM content (Shwitched Bank Paging ROM Cartridges - method 2.).

The next method is to read and map more single 16K ROMs into the RAM, then put them together into a single file. This was first used by the Spanish Insidro Nunez, who burnt the Knight Lore game into a 32K EPROM (Timed Bank Paging ROM Cartridge - method 3.).

A more advanced method the software controlled reading-mapping technique, instead of the previous method, when timing was controlled by the electronic circuit (Software Bank Paging ROM Cartridges - method 4.).

At last, it is possible to enhance the previous functions with the possibility of re-programming the Flash EPROM directly from the Spectrum. Then the maximum ROM size is 128K due to the limitations of Spectrum's memory (Programable Software Bank Paging ROM Cartridges - method 5.).

Paul made four separate generations from the cards: ZXC1, ZXC2, ZXC3 and ZXC4. These are available as empty PCBs, ready-populated PCBs, cased PCBs and ready-programmed cartridges.

The characteristics of different generation are the following:

ZXC1 is handles the 1., 2. and 3. methods. Supports 8K, 16K, 32K and 64K EPROMs. Two subvariants were produced: first batch has silvered edge connector (ZXC1 silver), the second got goldened (ZXC1 gold) to improve elelectric contact (otherwise, the two PCBs are identical). Was released in 2004.

ZXC2 (2008.) supports 1., 2. and 4. methods. Possible EPROM sizes: 8, 16K, 32K, 64K 128K and 256 K. In addition, it supports re-programbale 128K Flash EPROMs - but it is only possible to program them with an EPROM programmer.

The next generation is ZXC3 from 2009, which extends the capabilities of ZXC2 with the possibility of re-programing the Flash EPROM directly from the Spectrum. The card utilises the 5. method, as well the standard and simplified 4. method. 8K, 16K, 32K 64K and 128K EPROMs are supported, and it is backward compatible with ZXC2 up to 128k. With a simple modification, ZXC3 also can be enhanced to 256K. As mentioned above, in the case of ZXC3 does not need an EPROM programmer. Via the RS-232 port binary data can be sent to Spectrum. From that point, the Speccy can program the content into the Flash EPROM. For ZXC3 also available a Microdrive emulator ROM, which offers 75K storage by the BASIC commands of Interface 1.

In 2013 was released ZXC4, which is able to use 256 banks, reaching 4096K maximum, comparing of ZXC3's 128K. In addition it is capable to access the whole 16384 bytes, opposite of the ancestor’s 16320. Another novelty is to simulate the paging mechanism of Interface 1, so we can get 4 megabytes of FlashROM. It is usable as either as a Microdrive or cassette tape simulator. All ZXC is compatible with the Spectra interface.

For all of these cards usable the Windows-based ZX Cartridge Utility. With this, .Z80 and .SNA files can burn into the EPROM with an EPROM programmer.

The SPECTRA interface is a multi-purpose interface for the 16K/48K ZX Spectrum. Its primary function is to allow the Spectrum to be connected to a TV via a SCART socket to produce an RGB picture that is sharp, bright and completely free from dot-crawl.

SPECTRA interface plugs into the expansion port of the Spectrum and connects to the TV using a standard SCART cable. There is no need to make modifications to the Spectrum since the interface only requires access to those signals available on the expansion bus. The Spectrum's sound is also directed through the SCART connection to allow it to be heard loud and clear through the TV speaker(s). The clarity of picture and sound is equivalent to that only seen when using the monitor socket of a 128K Spectrum or a Spectrum emulator.

An exciting additional feature of is its ability to extend the Spectrum's display to support 64 simultaneous colours and at a variety of increased vertical resolutions, resulting in a total of 32 different display modes! Support is also provided for multiple screen banks, similar in concept to that featured on 128K models. At long last, the limited colour abilities of the Spectrum can be overcome, opening the potential for new visually stunning programs.

It also provides the following: a Kempston joystick socket, a ZX Interface 1 compatible RS232 socket, ideal for connecting to a printer, modem or a PC, a reset button, optional support for a ZX Interface 2 ROM cartridge socket, optional support for an onboard ROM to override the internal ROM. Further features: the ability to extend Spectrum BASIC via a ZX Interface 1 compatible paging mechanism (offering the potential to extend BASIC with commands to drive the new display modes); a rear, full width gold plated expansion bus, a set of configuration switches to allow each new facility to be enabled / disabled, ensuring full compatibility with all existing hardware.

All features come as standard, apart from the ROM cartridge and onboard ROM facilities. These are mutually exclusive and so it is left open for the user to fit whichever socket (if any) they prefer. Should you wish to use a Zero Insertion Force socket with the onboard ROM facility (useful if you intend to develop your own ROM software) then it is best to fit a turned pin socket first and plug into this. A standard IC socket is more suitable when you don't need to change the ROM very often.

This interface is constructed from a professional made board that measures only 10cm by 10cm. The interface will only operate with 50Hz models of the 16K / 48K Spectrum.

It may prove necessary in Issue 1 and 2 Spectrums to fit a wire link inside the computer to ensure a required video signal is exposed on the expansion bus (this optional wire link was fitted as standard in later builds of the Spectrum).

Later was realized the Spectra+128 interface also, which is compatible with 128K and 128K+2 machines. With the usual interface converter also compatible with 128K+2A/+2B and 128K+3 (we can found circuit diagram for example at Velesoft). It utilizes the shadow screen of 128K machines. As a result, with the appropriate software, you can even receive images on two monitors at once (Spectra Scart + Spectrum RGB). The cartridge port is standard in this case. The regular Spectra interfaces can be upgrade into Spectra+128.

Another area of DIY section the Scart leads for the various machines. Of course, we can buy them ready-made (see later), but there are full documentation for tinkering to all machnies including 128K (both UK and Spanish version), 128K+2, 128K+2A/B and 128K+3.

At last, there is information about how to rebuild the 'mysterious' Keypad (the attachable numeric keyboard) from contemporary parts. This one is originally designed for the Spanish 128K, but excellently works with the UK version as well with the 128K+2. He was realized it on a simple veroboard, but the printed circuit diagram is also downloadable from the website.

Updated: 2015. October

ZXC1 silver
ZXC1 gold
Spectra interface

Insidro Nunez's extension Spain

After we meet all five methods, follow the evolution through the hardware development. Droy's (Insidro Nunez) first invention was a 32K cartridge. In this a 27256 type 32K EPROM was used. This storage was divided into two slices with a jumper (or alternatively with a switch). With this, the JetPac and Pssst! Placed into the 2x16K version using the 2nd method.

Possible the further development in such way, that one 32K program loaded instead of two 16k? The answer: yes. But this needs such programs, which are not using the lower 16K. The author was tried it with Knight Lore. The method is the following: first we read the first 16K. Then 3 seconds break. In this time will be copied into the dedicated memory segment this 16K part, and after that, the top of that will be placed the same sized next segment. The PCB remained the same, but it needs the 27128 EPROM and a delaying circuit instead of the jumper (or switch) in order to work the 32K version with the 3rd method.

The ZX-Flash Card from 2005 based on Jose Leandro 's work. With this 10 pieces of .SNA files can be stored in the 29F040 Flash EPROM, and send them into the memory of Speccy. The method is the following. First we copy the original modified (but compatible) ROM. Then select the program we want to load. At the end of 16K segment will be placed a pointer, which shows where memory place have to copy the next part. The last part contains that code, which unifies the three parts, and launches the program. The Windows-based ZX-Flash Creator utility was made by Miguel A. Prada. This was realized with the 4th method.

What to do, if we have cartridges, but no Interface II? If we do not need the joystick port, quite easy to build one. All you need two ISA slots, wires and some plastic skirts to prevent short circuits. Speccy contains 56 contacts, divided into two rows. These must be soldered with the cartridge's one. Worth to delete the unused contacts, to minimize the chances of short circuits in the case of Make it yourself Interface II.

The +D floppy interface was already mentioned. For the purpose of more simple manufacturing, Droy was divided into two single-sided PCBs his own +D clone version. First module is the controller unit. This responsible for controlling the shadow RAM and ROM, and decoding the I/O tasks. The second module is the adapter, it controls the floppy and parallel port. It works with both DD and HD drives. In the last case of course it needs to jumper them into DD mode.

Although much more another PC-keyboard interfaces are exists, the IMAR-3 is a totally own development. Its hearth is a 16F84PIC microcontroller, which is essentially a microprocessor with a Flash EPROM. 'Edit' mode can be activated with the F12 button, Interface II joystick is simulated with Alt and cursor keys. It is compatible with AT and PS/2 keyboards only and not with the XT ones (although who would use them nowadays?). In order to better compatibility with Ultimate games, the 74LS245 chip was replaced with 74LS148. It contains a thoroughgoing Sinclair edge port, of course it can be abandoned, if we do not need it. Only compatible with 16K/48K/48K+ machines, 128K ones are not supported.

Aside of the above adapter, he has some another tips for repairing the weak point of the Spectrum, the keyboard membrane. He is suggesting to repair the cracked ribbon cable with silver paint. This fixes the cracks on the faulty wires. Also suggests to apply adhesive tape to make it firmer. For sure we can verify our work with multimeter. Also we have to take care not to make short circuits with the paint. Although the manual of the paint suggests to cleaning with alcohol, we can easily damage the good sections also with it.

Also we can fix the too short ribbon cable. All you need is to cut an old PC's adapter bus connector, and solder the wires onto it. On the picture seen the servicing of a ZX81, but of course The Spectrum's method is the same.

If the keyboard matrix is totally faulty, we can rebuild the membrane with micro-switches. It is worth to use 0,7mm thick PCB instead of 1,6mm one regarding the tight place in the Spectrum. The author only could obtain the 1,6mm version, so the project was realized with this. After drilling the holes of micro-switches, must make the circuit of the membrane into the PCB. Then to solder the switches, and finally put it into the Spectrum.

Another option is making a totally new keyboard from an old PC's keys. The method is similar to the previous one, after the drilled and prepared PCB must built the keys into it. So we can avoid of modifying the Spectrum. The project was made for the Jupiter Ace, but can be applied to the Spectrum too.

All above that, some error detection and servicing tips also on the webpage.

32K Cartridge for IF2 2x16K version
32K Cartridge for IF2 32K version
ZX-Flash Cart
Make it yourself IF2
+D clone
Repairing cracked ribbon cable
Elongation of short membrane cable
Recostructing of membrane with microswitches
Making new keyboard

Jose Leandro Martinez Novellon's extensions Spain

After Droy, Jose Leandro Martinez Novellon was released the Super Cartridge for Interface 2 based on the second method. It was developed in two different forms in 2004. The first one, the TTL based only reach the prototype level. Because the TTL not able to give compact realization. Programs are stored in a 29F40 512K capacity FlashROM. The GAL chip version is the same as the previous, but integrated into a single chip. So become possible the compact size, fits well into a Supertronic PP40 or PP56 box. So it can be flawlessly usable with the original interfaces. The card is capable to store 15 programs, from which we can choose from a software menu. From these, 10 is the original ROM game, and 5 another extra 16K ones was also burnt in.

It was the inspiration of the ZX-Flash Card

He was also joined into the ZX Spectrum +2e/+3e project. But was unsatisfied with the continuous noise of the winchester, and that it needs a power supply. So he voted to Compact Flash card. First, he was tried with CF-IDE interfaces, from that came the idea of making an integrated device. The external CF-IDE interface is connected to the Sinclair edge connector, and built into a PP6-N box. Also got a bugfix, thanks to Aitor's suggestion.

In the case of 16/48K(+) models not so easy to change the factory ROM to EPROM. The ROM replacement project gives detailed information how can be replaced the original ROM with 27C128 (16K) or 27C256 (32K) EPROMs. When once opened the Spectrum, worth to change the welded ROM slot into a replaceable one.

The External ROM interface is similar to the previous one, and based on Julio Medina's 'amazing machine'. The disadvantage of this and the previous one, that very few people wants to tinkering in the Spectrum. Although it was born earlier, because its more advanced design, described later. The interface is connected to the Sinclair edge connector, and the external and internal ROM can be selected by a switch. Also got an extra reset button. The 76x51,5 mm size was due to fit into the PP6N box.

Also worth to mention the PS2 gamepad adapter among his own developments. With the conventional Spectrums suggested to use with Interface 2, and in the case of 128K+2/2A/2B/3 must take care of the different joystick port layout. The hearth of the controller is the PIC16F877 unit, but works fine with any 16F8X7. Communication is done by the program written by Bruno Fascendini. Both joystick ports can be used simolutesosly, the another port controls the extra buttons. The easiest way of feeding with power the interface and the controller through the joystick ports, as the power consumption is as low as 25mAh. Also works fine with the Guitar Hero and Dance Carpet peripherals.

When trying to load programs into the Spectrum from modern devices, such as PC, MP3 player, the success is questionable. It is because the modern age players do not providing the signal strength of the old tape ones. On the Internet, numerous circuits available of low power amplifiers, and they are also commercially available.

The Ear input amplifier from 2010 is based on the LM380 chip. It contains a potentiometer which controls the strength of the incoming signal, and Joe was fixed it to 70 ohms. To eliminate the background noise, also got a 47pF condenser. To verify the strength of the output signal, was built in a KA2284 chip. This controls the VU unit, which is optimal, when the three LEDs are lighting.

Two prototypes were made, first was aimed the minimal size (54x43 mm). The second was made directly for the PP42 box in 64x55 mm.

All above that, we can found informations from devices of another Spectrum fans, as well some repairing tips.

Super Cartridge for IF2 TTL version prototype
Super Cartridge for IF2 GAL version
External CF-IDE interface
ROM replacement
External ROM interface
PS2 game adapter
Ear input amplifier

Gondos Csaba's extensions Hungary

Gondos Csaba (GoCom, Gondos Computer Communication) is the main constructor of Sinclair.hu and also a radio amateur. His first interesting development is the ZX Spectrum Smartmedia interface (ZXSM) working with 8, 16 and 32 megabyte cards. It needs to modify the ZX Spectrum ROM routines. On the homepage also can find some utilies and source codes for the interface software.

Csaba was also realized the more, selectable ROM Interface 2 peripheral, the ZX Spectrum Interface 2 Multirom. Price of the device was 6000 HUFs (approx. 15-20 Euros).

It was developed in 2003 and has more hardware and firmware versions. Their common point, that ROM-sections were placed into 16K segments, so they applies the 2nd method.

First version were contained the ROMs in 128K or 256 EPROMs, from which one is the loading module, where we can choose, what ROM segment we would like to activate. After loading it, it is prohibiting the ability of paging, so the machine only sees the actual 16K part. First 8K containing the loader program, second 8K is responsible for the paging algorithm.

In the second version only occupies 256 byte the paging algorithm, so the loader can be more complex.

In the third version, only the 3FFFh memory address part is retained for the paging process.

Can be used 128, 256, 512 and 1024K-s EPROMs with jumpers. So maximum 64 pieces of 16K pages are available. With using the 1024K version, the possibility to switch back to the original ROM is missing, so the 3FFFh address will present on every pages. Anyway, in the 256K version can hold all commercially released ROMs.

About the published firmware versions. The v1.2 was released in the same year, as the hardware. V1.3 (2005.) got new screen and some ROMs were change also. The cartridge now contained the Shadow of the Unicorn ROM, the only game ROM, which has its own special ROM; the ZX81 and ZX81 ROMs, which are useable in 128K mode, and emulating fully those machines. Also placed the GW03 Spectrum ROM improvement, and finally, the actual ZXSM (smartmedia card interface) ROM, for those, who do not wanted to build it into the machine.

In the newest, v1.4 a very rare – and commercially not available – ROM was also built in, the Sinclair System Test, which was only available for services at its time. And also we can found the ZXSM ROM update (v1.2).

Another two novelties, the G-Tech interface (ZX Spectrum analog joystick IF) and ROM-extension are connected to the game Ghost Castles from WSS-Team. G-Tech interface connected through the Kempston interface, and supports analogue joysticks. ROM-extension is a 256K extender attached to the Interface 2. Only this game is supporting yet. All documentations are freely available.

The next two peripherals are quite similar to each others. Their joint feature that they are working as a 'digital tape', but they look like a different peripheral. TZX mouse is a TZX player with 8 megabytes of internal memory, working from button battery and capable to handle maximum 256 files. With a battery, averagely lasts for 100 hours, and also supports turbo loading up to 4x speed. This TZX-player was introduced on the Megabit-X 2010 club meeting.

Joytape player is also a common development with WSS Team, the special version of TZX Mouse, and was debuting on the same meeting. But it was ready as a prototype built into a garage bell box in 2009. Integrating the thing into a joystick was the idea of Gyorgy Papp (Pgyuri) as the creation of the name of the device also. The device priced at 20 Euros (4999 HUF), and certainly contains all WSS game pre-installed and also a bonus one. Its operating time approximately 1000 loads with the built-in battery. Also an inner beeper was built-in, and the EAR cable is a standard accessory.

Another developments: reducing the power consumption in more steps and reconstructing the keyboard membrane from micro switches.

ZX Spectrum smartmedia interface
ZX Spectrum Interface 2 Multirom v3
G-Tech interface
ROM extension
TZX Mouse
JoyTape Player
Reducing the power consumption
Reconstructing the keyboard membrane

Scott Falk Hühn's extensions Germany

Scott-Falk Hühn from Germany among his numerous electronic projects also offering some development for the Spectrum.

The ZX Interface 2 - ROM module with 32 memory banks based on the 2nd method and utilizes the 29F040 type Flash EPROM. Anyway, any other compatible piece suits well, but the author was found this one is the most cost efficient. This has 512K capacity, so in theory 32 pieces of 16K ROM fits into it.

With a mechanical selector chosen the desired ROM content, which mimic like the original ROM for the Spectrum. It was made on a mini stripboard. If we did not found adequate donor for the connector, just reuse and old ISA card. The super-mini size was achieved by placing components even bellow the Flash EPROM.

Programming can be done even by the gadget and software found on the website. If we do not want to collect the ROM one by one, also we can download a subjective collection. This contains 16 pieces of ROM, so uses the half capacity of the nominal.

In the case of 16/48K(+) Spectrums the video signal is led into the TV-modulator, from when it was sent to the UHF channel. With modern TV-sets it is a clear disadvantage, as the picture quality is degraded. Because the video signal is present, worth to lead it out directly. Scott was fixed the RCA connector with two component glue. Some circuits found on the Internet, which are suggests to build an additional transistor for amplifying the signals. But the author got better quality picture without it. So was born the ZX Spectrum 48K video output hardware tuning. A very similar modding is done by Womble.

A very important and simple thing is missing from the Spectrum, namely the reset button. Although it is easy to restart the machine with interrupting the power, this is not the most elegant method. Much better to build a micro switch between the Z80 CPU's reset pinout and the grounding, an voala, the ZX Spectrum 48K reset button is done. The ground can be in different places on the different mainboards, the picture shows the Issue 4b. Fixing was done again with two component glue.

128K Spectrum has RGB output aside of the TV out. If we can, use it. But if no composite input on the monitor, as in the case of the author, time to tinkering. The poor quality of picture is caused by the D35 diode and R144 resistor. In fact, they are totally irrelevant parts, with soldering them out or cutting them can be reached much better picture quality. Quite interesting, these two parts was not built into the later Spectrums, achieving better quality.

Even be improved the quality, when separating the AY and beeper signal. Eliminating the C126 condenser in the same way, the picture will be clearer. This tip was suggested by Ingo Truppel. Applying the two modding together get the ZX Spectrum 128K improved video output name on the website.

The MIC output of the 128K audio has several disadvantages. Firstly, very unbalanced, as the beeper is noisy and the AY-chip is quiet. Secondly, it needs continuous plug in and out, when using tape recorder. The ZX Spectrum 128K additional sound output is a mini circuit, which solves the problem. It contains three resistors and two condensers, which controls the beeper, AY-chip and the MIC/EAR. The resistors are balancing the beeper-AY and MIC/EAR volume, and the two condensers are separating the MIC/EAR signals from the AY-chip. Sound is come from an RCA socket, which was built into the RGB and video out.

128K Spectrums were made in more different versions. At the moment, we look them from the viewpoint of Keypad and MIDI/RS-232 ports. Was made such a series, when the Keypad is Sinclair-standard square type, and the another is D-sub one (unfortunately the pinout is non-standard, but this is not so important). The moddings found on the website (ZX Spectrum 128K additional RS-232/MID/Keypad ports) turns the two Sinclair-standard sockets into D-sub (combi Keypad and RS-232), as well to standalone DIN Midi-out.

As I was mentioned, the 128K+2 gives much better picture than its predecessor. But it can also further improved. The 2N3904 transistor is too weak, which is responsible for the noisy and unstable picture. When we replaced it to a greater capacity BC548C (it is found behind the RGB connector), the quality will significantly better. Also can be improved the quality with deactivating the audio signal from the video, all we need to cut out the C31 condenser. All of those tips were arrived from Ingo Truppel. Just use the ZX Spectrum 128K+2 improved video output name, like the author.

The sound is much better on the one and only grey Speccy, but far from perfect. The AY-chip is too quiet, the beeper is too loud, the noise of tape loading is super-loud. The solution: simple change the responsible resistors, with which we can adjust the optimal volume values, and we have done the ZX Spectrum 128K+2 improved sound output modding.

He also offers some another minor developments. Let's see them. In the case of ZX Spectrum 128K+2 the author noticed, that connectors are fixed a bit weak. With the more times mentioned two component glue, it is easy to fix this problem.

With the same machine Amstard introduced the non-standard joystick port. Although the conventional joysticks can be plugged in, they work only in one direction without an adapter or the special SJS joysticks. After the modifications, port one became Cursor compatible, the second is Kempton with an additional small circuit.

The combi RS-232/Keypad connector is using the previously 'crap' Sinclair standard socket, glued onto the top of the original Keypad port.

The 128K+2 ROM was changed compared to the 128K. Of course, the copyright message is different, and the tape tester routine also disappeared. Some another changes are exits, for example the address of the RS-232 routines. The original ROM was replaced with a double capacity 64K 27C512 EPROM. In this, both of the Amstard and Sinclair ROM placed. With a switch can be selected the desired one.

ZX Spectrum 48K video output
ZX Spectrum 48K reset button
ZX Spectrum 128K additional sound output

Phil Ruston's extensions Great Britain

Among Phil Ruston's creatures we could read about the V6Z80P 'platform' as well the Pendulum card, which improves ZX Spectrum compatibility.

The SMART Card (Snapshot (loader) Multiple Alternate ROMs & Test Card) was evolved from a homemade diagnostic card. This was contained a Flash ROM and a discrete logic.

The current hardware is CPLD based, has 256K of Flash memory, 128K RAM, as well SD card and Kempston joystick socket, with added reset and NMI button. It is targets such gamers, who want to play immediately after powering up the Speccy and they want it to be cheap. It loads an .SNA file within five seconds.

It is basically a multi-ROM selector. The firmware contains the manager program with which we can load, copy an delete programs into the FlashRAM. The author was installed its own diagnostic program. It support the .SNA files, and many .TAP files are also usable.

The card is compatible with ZX Spectrum 48k(+) machines. Also works with 128K ones, but they can not be connected physically. So if we open the cases, will work (can not be more simple ribbon cables?). On 16K models only the DiagROM works.

The first serie is made on green PCB, the second on blue.

Here we also can found tips for making composite video output for the ZX Spectrum. He describes two subversions: a condenser type and a capacitor one.

The condenser variant is more simple, it is compatible with most TV-sets, but maybe the picture will be a bit dark. The transistor one gives better picture quality, but do not works with every TV. The good news, that if done carefully, all of two are reversible. We can found detailed infos for making them on the website, and of course, every parts can be obtained though the webshop.

The 128K+2 often mixes yellow/cyan shadows into the RF and composite output. The inductor and condenser inserted into the TEA2000 video circuit can successfully reduce it. It can be bought in 'set' as 15uH inductor and 82pf Capacitor for Spectrum 128+2 Video mod.

Added: 2015. July.

Pendulum v1.1
Pendulum v1.1b
SMARTer Card

Aitor Gomez Garcia's extension Spain

Aitor Gomez Garcia's Internal CF-IDE interface project is the marriage of Garry Lanchaster's internal ZX Spectrum +3e/+2e interface and Jose Leandro's CF-IDE controller. Unfortunately last one was only compatible with the SanDisk brand units, so it was buggy. The solution is quite simple anyway: the BC327 transistor and the connecting 100K resistor must be replaced to a single 10K resistor (Jose was later corrected this error).

The controlling unit was also redesigned into a more cost-efficient one, based on Lanchaster's internal unit. The Compact Flash adapter was built into the cassette player of 128K+2. To be sure, he left open the possibility of tape (MP3;) loading with a jack connector. The controlling unit fits into the Z80 socket, and the two parts connected with an IDE cable, which feeds the CF-IDE adapter with power.

As it is also a 8 bit interface, the capacity of the cards will be half of the nominal. Aitor was proposed to construct a switch, with which we can choose the lower and upper 8 bit parts. So could be utilized the full capacity.

Internal CF-IDE interface

Ben Versteeg's extensions

The Netherlands

Kempston Mouse Turbo interfaces

From the hardware stuffs of the Dutch Ben Versteeg we already spoken. Only to call up the informations again, let's talk about once again the things, which are realized by the international co-operations.

He planned to improve the originally Czech developed MB-02+ disc interface with the name of MB-04, but Ingo Truppel (with who he is in friendly relation) overdriven him.

The similarly Czech Velesoft's Kempston Mouse Turbo interface is producing in small quantity with attaching English instructions and an optical scroller mouse in the deliver pack.

The external version of Spanish Rodriguez Jodar's internal PS/2 interface is also taken into production.

Recently, he thinks about integrating the previous two boards, so maybe we except a mouse+keyboard combi interface.

Through his blog can informed the latest news, and the actually ready assortment is advertised through EBAY, and he delivers by post the ordered goods.

Even further, created a stereo converter for the 128K Spectrum. This is a mini PCB, which is placed on the top of the AY-chip. The card supports the ACB and ABC stereo standards, we can choose by shorting or by a switch between them. The beeper is coming from each channel, volume is fixed.

Despite, that it gives crystal clear sound, got fairly much negative comments on the WOS forum. So Benji stopped its development. Anyway, the series of the first line is ready, and the documentation is available from the homepage.

Jose Leandro Novellon Spain
Gamepad PS2 adapter is connected to a ZX Spectrum+2A

The also similarly Spanish Jose Leandro Novellon is again offering some good ideas to enhance the ZX Spectrum with various interfaces.

Let's study first his RAMJET interface clone. The original one was the development of Microsat Hardmicro released in 1990 in Spain. Was planned for the ZX Spectrum +2A/B and +3, unfortunately will not work with the earlier models. This is a Multiface-like device, we stop running programs, insert pokes, and can save the programs to either to tape or disk. So, the Spanish solved the problems of the copy-protected disks. Jose not only cloned the card itself, but its box is also very similar to the original.

The external interface ROM is supporting the use of custom ROMs, without tinkering inside the Spectrum - can be gentling for those, who always planned a similar extension, but do not wanted to hurt the Spectrum. With a selector switch we can choose between the original ROM and the EPROM, and got an NMI and reset button additionally.

He is an enthusiastic user of Garry Lanchaster's ZX Spectrum +2E/+3E clone, but like another users, was irritated by the use of power supply and the noisy operation. That's why he changeover to the Compact Flash cards. He describes three submethods of using them. Fist one is using a simple CF-IDE adapter for the already available board. Its main disadvantage, that the CF card still must be feed from external power source.

So made some own constructions, which named jointly to Compact Flash +2E/+3E interface. First version included the IDE controller and the solution of power supply on the same PCB, but without the CF slot. Immediately constructed an inetrnal and external version. Further development of this card is a complete interface, which integrating also the CF-slot on the board.

The gamepad of Sony Playstation 2 also successfully connected to the Spectrum with the Gamepad PS2 adapter. This using the two joysticks ports. Author is suggesting the use of Sinclair 2 compatible interfaces, but theoretically compatible with all types. Works smoothly with Dance Carpet, but has some problems with the guitar of Guitar Hero.

Also cloned Interface 2 cartridges, the TTL version was soon followed by the more compact GAL chip variant.

All above, some smaller or bigger own modifications (faulty sound jack and PAL chip replacement, ROM exchange) and analysis of classical devices also can be found on his website.

Aitor Spain
Pera Putnik Simple 8 bit IDE interface Compact Flash version 2 internal bugfixed

The again Spanish Aitor's internal IDE interface is based on the card of Jose Leandro. After a simple bugfix, and learning the low cost finalisation of the board started to construct it.

The interface is mounted into a 128K+2A machine, into the place of the cassette unit. To be sure, built in a jack connector, if sometimes want to load from tapes.

The card must plugged into the socket of Z80 processor. At the moment, this one is also only uses the half of the nominal capacity of IDE devices, as it is an 8 bit card. Aitor wants to further develop it with a switch, with which easy to choose between the low 8 bit and high 8 bit areas of the card, and accessing the whole 16 bit capacity in this way.

PCWKing's extensions

Great Britain

The English John R. P. King (or as he calls himself: PCWKing) principally well-known about the tune-up of Amstrad produced computers. So, among the whole range of CPC, PCW series and the NC100 machine, also using the ZX Spectrum +2, +3, +2A and +2B.

The DIY section can be divided into two sub-parts in case of the Spectrum: making of various cables and modification the Achilles-point of +3, the floppy system.

The first cable is a monitor cable for attaching CPC monitor for the +2, +3, +2A and +2B. Well, this is basically a converter cable between 8 Din (Speccy) and 6 Din (CPC) connectors, which gives superb picture with the CPC unit. Unfortunately, sound is not driven by this method.

Similar is the RGB-Scart converter cable for +2, +2A and +2B machines, this was designed by Alan Cox. It also contains some resistors. Opposite of the previous cable, this also contains the sound output (in mono). The picture is far superior, which can be obtained on a monitor.

The next DIY cable is Centronics cable with which standard printers can be connected to the Amstrad-originated Spectrum models.

The last cable (which is also the most simple one) is a tape cable for the +3. Here a stereo jack is converted to two mono ones (MIC and EAR).

The another area may catch the interest of +3 owners is the different floppy disc modifications.

The most simple one is the external 3 inch drive attachment method. For this only need a standard PC 5,25 inch cable floppy cable, from which maybe cutted down the unnecessary second floppy connector.

Adding a 3,5 inch unit is muck more trickier. As 'modern' 1.44M and 720K drives working solely with 5V, the 12V line line from Spectrum must be cutted down or must be fitted a 5V regulator.

Another difficulty, that not all 1.44M drives are working fine in 720K mode, as they missing the 'Ready Signal' (this is indicating, if there a floppy disk in the drive or not). For testing this feature, there is also a hint on the homepage.

The next problem is if we have the compatible floppy drive, that they will use 180K as standard. For solving this problem, there is also a simple side switch circuit on the homepage. This issue is also can be solved with a ROM replacement.

Módosítva: 2010. augusztus 07.

Graham's extensions

Great Britain

ZX Spectrum +3e mod 1st version by Graham

Graham also primarily focused on the Amstrad manufactured machines, and also made modifications for attaching an external floppy drive. Opposite of PCWKing, he not only trying out the possible compatible 3,5' drives. He went further, and constructed his own disk-ready -> disk-change signal converter board. With this, easily can be compatible with all floppy drives the ZX Spectrum 128K+3.

Construction is quite simple, based on a 74LS38 type logical gate. By the way, for the another retro (made before 1990) computers the circuit works fine. If not so, with utilizing the rest gates of 74LS38 there is also possible solution on the webpage.

In addition, Graham also introducing a regulator circuit, which solve the 5V power supply needs of the floppy drive.

He also worked on the further development of 128K+3e. For starting point, used the Pera Putnik simple 8 bit interface. For the first attempt, the power needs for the HDD of an old laptop is feed from the power connector of the Speccy's PCB. The shortcoming of this method, that during power on, the hard disk do not get enough power to spin up fully, so the +3e will not recognize it. It can be solved by pushing a simple reset.

In the second version, the winchester was replaced with an 512K micro memory module, which is an early version of SDD. This has low power consumption, and has no spin-up time, so adopting the previous method, no need to reset after power up. The circuit remains the same, only the socket of card became vertical.

After upgrading the ZX Spectrum 128K+2 to +3e, in this machine was moved the old laptop hard disk. The power now comes from the CPU.

Also we can read about a 128K+3e modification for the ZX Spectrum 128K+2. The size of the original ROM of +2 is 32K, and +3 uses 64K ones. As these old ROM modules can not be bought as new, Graham used a 128K EEpROM. For building this modification, also necessary a 28-32 pin converter. We can choose with a switch from the extra ROM the necessary ROMS: 48K, 128K+2 or 128K+3e.

Updated: 2010. September 26.

Hw.speccy.cz's enhancements Czech Republic Slovakia

Those, who are visiting the hw.speccy.cz website, gets exactly the same as the domain suggests: hardware tips for the Spectrum from the Czech Republic - but of course with the involvement of the Slovakian colleagues. Maintainers of the site: z00m and Ik0n (Imrich Konkol).

The first novelty is an universal 128K expansion for ZX16/48 (all issues) and Didaktik Gama machines (all subversions).

Its designer was Zilog and it is the third revision of the hardware. Fully compatible with the original 128K and FastIO and Unrain is also supported. These can be activated with a swicth. It is even supporting the second video RAM.

The tuning is consists of two main steps: installing and wiring the new chips and then building their controlling logic. This modification for advanced users.

The Simple AY-interface is based on MDV's idea. The ABC stereo mixer constructed by Zilog's 'golden ratio'method, so the best AY-sound is guaranteed. This two parts were made togehther by z00m.

Simply have to to place the components onto the universal board and wire them. Can be mounted internally or can be build as an external interface.

In the next year, Pavel Urbancik designed a neat PCB for it, which was named to Nice board. It has two revisions, so the first was made in 2011, second was realized in 2014.

The Memory LED map is the creation of z00m and Busy. This contains 64 LEDs inline or as a 8x8 matrix. Each LED represents 1kB of memory, which flash up when the CPU reads from it (very useful when cracking).

Components can be placed onto the universal board or onto the authors' prototype PCB. Can be mounted internally or built into an existing interface (MB-02+, Betadisk, +D...)

The Dual color memory LED map is the further development of the previous device made by Ik0n. Can be ordered through E-Bay.

The Bank LED map of z00m is indicates the function of port 32765. It works with 128K and 128K+2 machines.

On the picture, the previous version is seen. The new one has a slightly modified circuit diagram, but functionally is the same.

Z00m did not placed the LEDs onto an universal board, but sticked them from internally onto the case of 128K+2

The simple D40/80 modification for 128K or 128K+2 is also Zilog's development (anyway many others also made similar modification). After the simple rebuild, with a switch can select between the standard 128K or the D40/D80 compatible mode. Tritol was also done the +2A/2B compatible method also.

The ZX Spectrum +3e^2 machine of Ik0n is the further development of the ZX Spectrum +3e. Its main purpose to stay compatible with both the original +3 and the +3e. First task is to make the ZX Spectrum +3e conversion along with the two selectable ROMs. With a switch, the default mode is +3 (DivIDE) and the another is the +3e.

Among the +3e extensions, he was chosen the 8 bit Pera Putnik CF interface due its simplicity. As home-made soldering of the CF slot is quite difficult because of the small size, so he choose to solder of the IDE socket instead. The CF card can be attached through a separate CF-IDE converter. The slot of the CF card placed bellow the already replaced 3,5' floppy disk drive. Was also published on the website of Sindikat.

Also we can find both for the grey (128K+2) and for the black (128K+2A/B) Spectrums complete developments, which are named simply to 'ugly hacks' by the author. These modifications are really cheap ones, so no idea, why Amstrad did not applied them.

The 128K+2 tuning begins with the RF and composite video mod. First step is to desolder the C31 condenser, which mixes the picture with the sound. Of course, the sound will not will be heard through the TV speaker, but it will be resolved later. In the case of composite video mod, simply have to rotate the TR4 transistor, if the picture is distorted or black and white.

When the machine is cold, the Symbol Shift+A combination (and possibly some another keys also) do not working. This is caused by the overloaded address lines. The solution is to put a 82 or 100 pF ceramic condenser over the D35 (or in some cases D33) diode, and this problem will disappear.

The already mentioned unrain bugfix is also can solved in the case of 128K big brother. The original PAL10H8 chip must be replaced with a reprogrammed GAL16V8 chip. The recompiling, which was necessary for the bugfix, was done by Poke Studio.

The ACB stereo output is also known already. The beeper is connected to both left and right channels of the ACB stereo mixer with a simple transistor amplifier through two 1K resistors.

Owners of 128K+2A/B also may get some ideas for the ugly tunings.

The RF out and video composite mod s similar to the above, but here the C24 condenser must be removed. The composite video output is completely missing from this machine. Suggestion: to fit inside the original circuit of the 128K+2.

The sound of black machines are even worse compared to the +2. The ACB stereo tuning is very similar to the previous, but here must be applied 2 pieces of 2K2 resistors as the beeper is a bit louder.

The Old ROM replacement is for those, who has not have the v4.1 ROM, but owning the older v4.0. Although the new is still not perfect, a lot of bugs were corrected. Needs two 27C256 EPROMS for this modification.

And about the tuning of MB-02+ with new EEPROM we could also read ( MB-02+ modification–28C256).

Updated: 2016. February

Universal 48K to 128K rebuild
Simple AY interface
Memory LED map prototype
Dual color memory LED map
Bank LED map
D40/D80 mod for ZX128K/128K+2
ZX Spectrum +3e^2
Ugly hacks for ZX128K+2
Ugly hacks for ZX128K+2A/2B
MB-02+ modification - 28C25

Sindik.at's enhancements Czech Republic Slovakia

The SinDiKat community was founded in 2009 in Bratislava, Slovakia. The meaning of abbreviation is Sinclair a Didaktik - Klub Aktivych Technikov, that is Sinclair and Didaktik - Active Technicians' Club.

The head of this the already introduced Ik0n and more respected persons (eg. Noby, Busy) and teams (ci5, Zero Team) joined to the initiative. Their hardware and software developments are presented in the meetings to each other - meanwhile they are communicate on-line.

The first hardware-hint is the construction of Philips HCS 130 Videotext Terminal's keyboard interface for the Speccy. The keyboard was bought in 1992 by the host of the blog, and was used until 1995, the end of his active Spectrum era. The frequently used floppy and printer commands are mapped to the function keys. A number of special buttons are working as the usual 'double combinations' of the Spectrum.

Ik0n also published a 128K expander, which Matsoft sent him in 1994. Memory paging is completely 128K compatible, but using the second vieoRAM is not solved. Although today is technically much more advanced methods are available for constructing such expansions, for the fans of classic tuning is worth taking a look at this well.

We could read about the ZX Spectrum +3e² machine in the Hw.speccy.cz section.

Also we can read about restoring a Didaktik Gama 80K.

The machine was bought from auckro.cz without any cables and power supply. The motherboard seemed good, except from the missing antenna connector.

For the first time, the bad memory chips were replaced with the controlling circuit. For sure, 128K memory is incorporated instead of original 80K - leaving open the possibility of future expanding.

First only the low 16K, later the upper 64K worked fine.

After cleaning the housing, the base paint, then the final paint was done. The keyboard was renewed with an alcoholic marker. This was followed by replacing the missing LEDs, along with the reset button. The antenna connector is replaced with a cinch socket. At last, the power supply was an USB/PATA converter box after replacing its original power connector.

Petra Kourila (PedroS) was realized sadly, that after arriving home from ByteFest, the keyboard of his favorite machine was did not working. As the membrane was healthy, only the ribbon cable needed to repair. For the elongation, he was used colored multi ribbon cables (the IDE cable was to rigid). Its first end was soldered to the ma inboard, the another to the connector was made for connecting the membrane cables. Before servicing, he put out all heat sensible ICs, and after soldering, was secured the cables against going out with tape sticker. So was made his membrane ribbon cable repair.

In Ik0n's 128K+3 machine was also died the TEA 2000 chip. As a temporary solution, three 330 Ohm resistors was soldered to the RGB output, which only gave black and white picture through the composite output.

The final idea was born on Miguel Jodar's project, which utilizes the Analog Devices AD722 chip. It was available under 10 Euros including shipping costs.

He was also applied some minor changes on the TEA 2000 replacement daughterboard. A bit enlarged it, changed the type of stabilizer IC, and used only two jumpers instead of three. Another modding was to eliminate the 20pF condenser, which resulted color picture instead being black and white. The 75Ohm resistor was also replaced to a 200Ohm one, giving better picture quality.

Mike (mikezt), the member of zeroteam was frustrated about overheating of the 7085 voltage stabilizer. Finally, he deiced the 7085 replacement with LM2575HVT-5.

The 2575 has five legs. Only the required to use the input (pin 1.), earth (3) and output (4) connections. The pin 5 also recommended to be grounded, the pin 2 and was connected to the speaker.

Due to lack of space it was connected with a help of an insulated wires to the motherboard. Heat production was ceased, so mike got calm, the overheating will not damage the machine.

DGBoot is the adaptation of the SpeccyBoot for Didaktik Gama machines. Since they have 8255 Intel-based parallel port, easy to connect directly the ENC28J60-H card. You do not need nothing but a 3.3V voltage stabilizer and a modified double-capacity 27C256 EPROM (32Kx8) in the computer, as well as some resistors and a jumper.

Compared to SpeccyBoot the price cheaper and it is easier to build. However, a little slower, because using different I/O ports.

Starting from 128K Spectrums the existence of a serial port became standart. The RS-232 was implemented through the open I/O ports of the AY-chip, which leaded out in a British-style telephone socket. This is controlled by the 128K ROM.

Virtually undiscovered and therefore unused this function. Using the Serial Peripheral Interconnect (SPI) protocol implemented in the ROM was made the +3MMC card.

It is more years old project. The data storage device was realized on an universal card with six resistors, a stabilizer and some diodes. Three LEDs are indicating the work and has an SD card connector, which accepts FAT file system cards. At the other end of the line got the Centronics mother socket of 128K+3, but it can be connected either to the AY-chip or 8255. The design was made together with UD880D (Dusky).

Ik0n's Video-to-VGA converter is not a ZX Spectrum peripheral, but it would be handful to know about his experiences. The test was inspired by the similar device of z00m, which is looks the same from outside, but inside… He was tested it with more machines.

It has S-Video, Composite and VGA outputs. For the ZX-tests, he was choose the 1440×1050 resultion, as it was the native of the HP monitor. First test was done with an Issue 2 machine, blur but stable picture. On the borders, blue colourizing was appeared.

The 128K+2 brought disappointing results. The picture is noisy with yellow ghosting, and sometimes with loosing colours. Quite intersting that they were less visible with the tested demo.

The best result was got with a Didaktik Gama.

Latest test was done with a 128K expanded Issue 6 plus machine. Colours were stable, and was not visible the colour problem of Issue 2.

Updated: 2016. March

Ribbon cable repair
ZX Spectrum +3e^2
TEA 2000 replacement daughterboard
7085 replacement with LM2575HVT-5

Lotharek's extensions Poland
DivIDE 57 2k14

KempAY interface is the first own development of Lotharek, which was begin in November 2009. This is a combined card of a Kempston Joystick Interface and AY-card, and it is also Sinclair joystick compatible. The joystick part has only one connector. The AY-part is 128K compatible. Of course, it has a thoroughgoing edge connector. The further development of this card is KempAY CPLD, which was made with ATF1502 CPLD and contains a joy tester and a reset button. Got two RCAs instead of the stereo jack.

The interface is not available now, but sliced into two parts, can be ordered by anyone. WonderAY is a standard AY-interface. The price does not include the sound chip, but of course it is also can be ordered. A development from 2010. The Simple Kempston is a simple Kempston joy interface, just as the name suggests.

The Angry Space Invader from the end of 2012 (on white or black PCB) is a Kermpston and Sinclair interface. Again built with the ATF1502 CPLD and its extras again the LED joystick tester and reset button.

Specially for 128K owners was made the ZX Spectrum 128K/128K+2 64 KB SRAM replacement. This replaces the base lower (video)memory. Of course, first have to remove the original RAM modules, then to solder the socket of the device. After with seven pieces of short cables connect the PCB with the DRAM data lines of Spectrum.

His DivIDE 57c clones clones, DivIDE 2k11, DivIDE 2k14, USB HxC and SDCard HxC Floppy Emulator already mentioned some paragraphs earlier

Updated: 2013. April 27.

Lotharek: http://lotharek.pl/

Victor Trucco' enhancements Brazil
Beta 128 Plus


As in the post-states of the former Soviet Union the Beta-128 disk interface became dominant, it became in Brazil its predecessor, the Beta-48. Trucco was dealt with both of them, let’s see the results!

The author chosen the IDS 2001 clone for rebuilding. Jorge Braga was written its documentation, so Victor wanted to contact him. However, there was no answer, so jointly with Flavio Matsumoto prepared the PCB for mass production.

Already the first prototype was good quality, but in some places had to be redesigned to make more room between components, thus easier to implant them.

In the first revision two islands left short-circuited, and a few other similar, smaller errors was occurred. In addition, the holes must be expanded. The biggest mishap, however, that a line is accidentally deleted from the drawing which was sent to the factory.

At last, the final version of IDS2001 disk interface clone was flawless for the first time, from which 60 pieces was made for the members of TK club.

Its further development the IDS Plus interface, which is the marriage of an SD card drive emulator and the IDS2001 disk interface clone in a Palace plastic box. The reasons of implementation, that the already existed Beta 128-Plus was only compatible with 128K machines. Not only the box, but the SD card reader part was inherited from the earlier born 128 version.

The Beta 128 Plus interface is the SD-card version of the previously mentioned Beta-128. This is based on Jorge Braga's 'wired' Beta 128 interface, after his friend, Marcus Garett sent him to repair.

After repairing the interface, Victor made the PCB variant of it based on Braga's document. This is more neat, smaller and also more reliable.

The following minor modifications are making easier the life of (Brazilian) ZX Spectrum 128K+2 owner.

The first mod is a simple one with the purpose of making available the Spectrum work with 110V power supply (which is the standard in Brazil). This type of supply can be bought nearly everywhere, but the Spectrum needs reversed polarity. The most simple way to rewire the supply itself, but it means the lost of guarantee. Instead of this, he is suggesting too crossing of LK5 and LK6 jumpers inside the Spectrum to achieve the desired result.

The missing power button is one of the faults of the manufacturer. It would cost half pound, and would not be necessary to plug in and out the power connector.

The tumbler was placed under the cassette unit. Must take care to put it as low as possible not to disturb the mechanic of tape recorder.

If the reversed polarity mod was not made, LK6 jumper must be deactivated. Useful to glue the wires to the bottom of the machine box not to run into the parts of the tape recorder. It is purposeful to lead the wires to the mainboard under the heatshink.

He is offering two methods of making composite video output.

The "1a" variant of the tuning is more simple. Looking near the RF modulator, we have to see a TR4 transistor, 3 diodes (D7, D8 and D9) and a 75 Ohm R12 resistor.

For first, ZN3904 transistor (TR4) must be replaced with BC237. Theoretically, they only differs in polarity, but BC237 offers better picture quality. Must be sure, that LK1 and LK4 jumpers are closed, and LK2 and LK3 are open.

Then desolder the small resistor inside the modulator, which brings the video output to the centre of connector. This is in a small plastic tube. After it, must be deactivate the two wires, which are connecting the modulator the the Speccy’s motherboard. Finally, connect a wire between the centre of connector an LK4 jumper.

Basically, we are ready, but there is still a problem. When the Spectrum plays music, this leading interference with the picture. This is caused by, that adding the sound to the picture is done before the RF conversion. Solution is simple: remove the C31 condenser, which mixes the picture with sound.

Also exists a different mainboard, which is very rare. Seems, it is an intermediate one between the ZX Spectrum 128K+2A/+2B/+3 and the original gray cased one. So, the "2a" version of the tuning can be also applied to the black models too.

We have to build a mini-circuit and the most convenient way to place it to the empty RF modulator. As the metal box is grounded, must take care, that the parts do not touch it.

From the two wires, one is the 12V, another is the video input. First one have to solder to the pin 11 of TEA2000, last one must be connected to the L1 resistor. Removing the condenser responsible for interference is the same, in this case means the C24.

Making of audio stereo output is purposeful to begin with the RCA connectors. Worth to place it near the power switch, place the longest distance from the mechanic of tape recorder.

This followed by lifting up the R37 and R45 resistors. After it, have to solder the cables, the author was used three wired grounded one, from which the third is unnecessary. The rest of two cables must be connected to these resistors, the ground to the R41. The other end of cables soldered to the RCA sockets. Take care of the length of the cables, again not to run into the mechanics of the recorder.

R37 controls the AY, R45 is the signals of ULA. Varying of these two resistors, can be controlled the volume of the two channels.

The next modification is the stereo output. First step is to separate the audio signals from the video signals. It needs to connect the R37 and R45 resistors. For setting up the required volume, it is suggested to replace the R37 to a 4,7 kOhm one.

Using of standard Atari joysticks he offers two solutions. For making the Atari compatible joystick connectors needs to tinker the machine itself and needs skilled technician, good quality tools and materials. First, the joy controller chip must be desoldered. Then cut the ‘joystick’ track between the joystick connector and the modulator. Finally, the pins of the joystick must connected with the keyboard matrix and ready the Interface II compatible modding.

Making of Atari joystick compatible adapter can be recommended for those who do not want to disrupt the machine. This is much easier to do, needs two DB9 connectors, a female and a male. All you need to do to to solder the wires according to the figure.

Although nowadays less widely used the original cassette recordes, using the EAR input not be completely forgotten thanks to the project as O.T.L.A., which in theory can increase the bit rate to 38400 baud instead of 1500. The downside of using audio files with MP3 players, that usually the volume is not enough for TK machines. Two ideas have been raised, if you do not want to use a dedicated mini amplifier box.

First is to bypassing the integrated noise filter in machine. As any MP3 player has much better quality than the contemporary recorders, so it's useless. Volume level is raising with 20-25%, which is in most cases can be adequate. For filter inactivation R40, R41 and R70 resistors and diodes D13 and D14 have to be removed, which are close to the EAR jack.

Second solution is the TK-Ear Reloaded circuit, which is based on an LM358 SMD. In addition to amplifying, capable of transfer more balanced signal.

TK-Ear Reloaded 2.0 was birth accidentally. Since the LM358 was not at home, so Victor built a modified circuit around the LM324. Surprisingly, programs were loaded at any volume.

32K High Memory SRAM Replacement can be either repairing or tuning. With 48K machines it replaces the faulty memory segment, with 16K ones expands the memory to 48K. First step is to obtain a 8 bit 32K SRAM memory. Then have to desolder the U21-U24 chips, which needs skilled person. After, depending on the size of the new chip, to the top of the ROM (full size chip) or to the bottom of it (half size) must be to solder it. And the final step to solder together the wires and set the jumpers. Memory expansion to 48K goes in the same way, but here must be soldered the 47LS32 and 74LS00 chips, which are controlling the upper memory area (by factory, a resistor is fitted instead). And finally only two resistors and condensers needs to be soldered and ready the fully 48K compatible machine.

One of the shortcomings of TK clones, the lack of RGB output. The ULA generates digital RGB signals, which is converted into composite video, then the picture goes out through the RF modulator.

Very few monitor able to handle digital RGB signal, so it is necessary to do analog RGB conversion. He was re-made the circuit of ZX Spectrum 128K + 2, even the 8-pin DIN connector is the same for the TK90X RGB circuit. The wiring diagram is otherwise the same as in the TKPlus project, however, the finalization is slightly different.

Using of the aforementioned composite video out signal as standard has some drawbacks. One of them is the poor image quality on modern devices, and the another is warming of the transistor. This is not causing problem, but worth to eliminate.

He was choose the 2N440 composite video signal amplifier proven in ColecoVision video out when creating the TK90X A/V Reloaded circuit. For even better results, was deactivated the R52 resistor, which is mixing the picture and sound.

Seems that using memory cards (instead of HDDs) were in the minds of oversea owners also, that's way were born the ZX Spectrum 128+3 CF. Alvaro Feeders sent a Victor a +3 machine, to make the video and music tuning. The machine was arrived without floppy, supposedly saving costs. After doing the moddings, followed by the building of CF cards. Victor was used the Pera Putnik 8 bit simple interface with the appropriate English language ROM. The card was inserted into the Z80 processor slot. First tests were done with using the CF-IDE interface directly. After the successful result, the CF unit (with some epox glue) was fitted into the place of floppy drive. The last task was to connect the parts with an IDE cable.

Updated: 2013. november 24.

Alistair MacDonald's extensions Great Britain

Alistair MacDonald is a software engineer, but despite this, mainly doing hardware developments. In his focus there are the Amstrad-era Spectrums.

With the external floppy connector of 128K+3 and 128K+3B easily can be connected 3,5” drives to these machines. This unit is present as 'B', while the internal remains 'A'. It is possible to force the Spectrum to use the external drive with a special cable. This is done by shorting the 'direct select' line of the external one. It has some disadvantages, first disappearing the possibility of automatic selection, and secondly could harm to the electronic circuits when used for longer period.

A much better option to make be switch-able the drive select line on both drives. This is the aim of the Drive swap switch on the +3 or +3B simple tuning. For this, each of the internal (drive0) and external (drive1) line must be cutted, and make switch-able the two ones with crossing the signal. And of course, be selectable the 'normal' and 'swapped' mode with a switch.

The ZX Spectrum 128K+2A and +3 was (in)famous about their bad audio amplifier. These were corrected in the later 128K+2B and 128K+3B models. It is possible to do this fix with the 'fisrt generation' machines, it is a kind of upgrade. For this must be replaced seven resistors and add further two to made the Fixing the sound on the Spectrum +2A/+3 hardware patch.

The Flash adapter for the Spectrum +2A/+3, +2B, and +3B is an add-on board, in which the content of two original EPROMs is placed into a single FlashROM. Also known as Flash Rom Replacement for the ZX Spectrum +2A/+3, +2B, and +3B. The mini card must be inserted into the place of the original two EPROMs. It has 128K full capacity, from which only see the half of the content the black Amstrad Speccys. The desired part is selectable with a jumper.

The first prototype is built with the W29EE011 chip. This was single time writeable, and needed an external burner (for example used with PC).

The base of the second prototype was the AM29F010B 128K FlashROM. All of two was made on tripad card.

Of course, the final version was made on professional PCB. It was available for 10 pounds, but now stock is out. Now burning can be done directly by the Spectrum, after write protection was disabled with a jumper.

The second edition is more cost-efficient in small series of production. Its hearth is a AM29F040B, which capacity is quadruped of the previous. If enough requests are coming, could be started the series.

The solution of audio problem and applying the FlashROM card together is a very important step to create the 128Ke machine, the idea of Andrew Owen, and which could be the ideal 128K machine. Owen was collected complete ROM sets, which can be downloaded from the website.

The essence of S-video out for the ZX Spectrum +2A/+3, +2B, and +3B, as its name suggests, to send S-Video compatible signals to the TV. But it is easy to damage the TEA2000 modulator when using it nonstartad way. So the authior is not recommending this mod, his own unit was also restored to composite.

For me the technical text is bit high, but must to cut the resistor between the LUMO pin (luminance out) and LUMI (luminance input), and applying some transistors instead them as buffers, and can we get clearer picture.

The ZX Keyboard project turns the (dead, but with good keyboard membraned) Spectrum to an USB keyboard. The device works in two ways. When single keys are pressed, the relevant HID code is transmitted. When Caps Shift is pressed, again the same happens as with a normal keyboard. Of course, the number keys are excepted, it sends the cursor, delete etc. signals. The commands and symbols accessible with Symbol Shift, divided into two parts: some goes out directly, another going out as 'converted' (for retaining emulator compatibility).

Nice idea, but the most criticized point of the Spectrum is its keyboard. But seems OK for emulator use. Anyway, it is based on the Arduino development platform.

Updated: 2015. July

Drive swap switch
Flash ROM adapter prototype v01
Flash ROM adapter prototype v02
Flash ROM adapter
Flash ROM adapter Second Edition prototype
S-Video out
ZX Keyboard

Mikhail Tarasov's enhancements Russia

We have meet Mikhail Tarasov's (Mick) name multiple times. For example at ZXM-Soundcard series, ZXM-GeneralSound, as well with various clones, such as ZXM-Phoenix, ZXM-777, Pentevo Light and ZXM-Zephyr.

ZXM-Moonsound card is MSX-originated. First was appared as Moonsound on Tilburg computer fair by Henrik Gilvad. Its modern age reincarnation was came out in 2012, with Wozblaster name from an Argentinian fan, Gustavo Iriarte (Ciro). In the next year, Eugene Brychkov was modified so, to fit into a standard Konami cartridge.

In 2015 on the zx.pk.ru forum came up the idea of the realization of the Spectrum version with ZX-Bus. Due to the differences of two platforms, it is not controlled by GAL16V8 but by the Altera EPM7032STC44 CPLD. The most important part of it is the Yamaha YMF278 (OPL4) chip. On this card, it is capable of 18 channels of FM-synthesis and playback of 24 channels of 12 or 16 bit audio.

It has 1 megabyte of RAM and 2 megabytes of ROM. First can hold the user defined samples, last one contains the built-in General MIDI instruments.

Outputs: stereo jack, double RCA, four pin audio out. Four demo diskettes, and a 'service' one was released for the 24 pieces serie. Dmitry Pugachev (DJs3000) also gave advices for the development.

The primary aim of the ZXM-VideoCard is to able to connect the ZX clones to VGA monitor. The homepage also mentions 'advanced graphics capabilities', but no further mention about that.

There are also being development two another cards, ZXM-ProfCard and ZXM-LANCard.

To simplify of developing ZX Spectrum peripherals, also created a Devboard Z80 development card. It is a card equipped with Z80 (compatible) processor and Nemo-bus. The Altera EPM570 is Flash-based, so it has limited rewriting cycles. The card is capable to simulate every (future) peripherals, even can mimic a Spectrum itself.

The size of RAM can be 512-1024K SRAM, the ROM size is 512K. Picture output is VGA. It has standard PS/2 keyboard connector. The communication is realized by RS-232 serial port as well by an SD-card reader.

Updated: 2015. December

ZXM-Soundcard Extreme
ZXM-Phoenix rev 05.1
ZXM-Phoenix 2
ZXM-777 rev 01
Pentevo Light
ZXM-Zephyr rev 00
Devboard Z80 rev 00

Winston's enhancements

Great Britain

Spectranet Issue 1

The first peripheral of Dylan Smith (Winston), the Spectrum Flash ROM and Diagnostics Board was built for the 25th anniversary of the Speccy in April 2007. Producing this card is 'totally free', as all documentations are available, and all software is freeware which is needed for creation.

The purpose of the card is if at least the Z80 processor is working; it examines the memory, ULA and the ROM. It partly communicates on the screen, but when ULA is faulty, problem can de identified by the error codes of the LEDs. The PCB is optimized for homebrew finalization (hand drilling and welding). The size of Flash ROM can be between 128K and 512K. So we can burn inside anything with a help of a (working) Spectrum.

The aim of Spectranet Ethernet card is to put the Spectrum online again. This was realized in the past with the Prism VTX 5000 modem and Interface 1, as well with the RS-232 port. Unfortunately, these methods are out of dated now, so totally incompatibles.

The card is built around the WIZnet W5100 single-chip Ethernet device. This was specially designed for embedded 8 bit systems, so ideal for the Spectrum. The controlling logic is done by a Xilinx XC9572 CPLD CPLD. 128K FlashROM and the same amount of RAM can be found n the board. First one can be programmed from the Spectrum, and various programmes can fit inside. The RAM is reserved for special programs, and also for general purposes. This card is also can be reproduced homemade, and also a free, open project. During the planning, compatibility was a priority. So it works fine with all Sinclair and Amstrad models, and also with the Interface 1, DivIDE(+) and joystick interfaces.

With is, can run Twitter client, IRC software, as well to play games on-line downloaded from WOS.

The SpectraDVI is still in a very early development stage. This is an ULA+ compatible HDMI interface with DVI-D connector and 480p resolution. It would be realized in a Spartan FPGA-6SLX9 as an external interface. Just plug in 48K, 128K, 128K or 128K, 128K+2 or 128K+3 machine, and it will work. It is possible that it will have a VGA output also.

The CPLD-based ZX breakout board is designed to provide access to the ZX Bus pins, and use them to further our projects. Whether the Xilinx XC9572XL or the XC95144XL can used to it. In the case of 128K+2A, 128K+2B and 128K+3 for the fourth pint must be disabled, all the rest Spectrums works perfectly without any change. The tool has been implemented in four-layer PCB.

The Spectramin a fun project, which is a Theremin controlls the AY-chip. The interface is based on the ZX Breakout card and uses the XC95144 CPLD.

It consists of two main parts: the Theremin, which is actually two separate Theremins each for one hand. The other part of the interface itself. The two Theremins controls the 1 and channel 2 (pitch and volume). There's even a foot pedal, which is slightly different from the Theremin concept, but Dylan do not have three hands. This can be used to manage the third channel and switch the musical instruments. It is advisable to operate it with battery, as the Spectrum's power supply is very noisy.

Updated: 2015. July

Winston: LINK HELYES-E!!!!

Piotr Bugaj's extensions Poland

His Beta-128 clone is based on the original. The schematic was acquired from Pavel Cejka (Cygnus) website. Compared to the original version, the system switch has only two modes: 48K and 128K. The reset operates separately as a microswitch.

Hozzáadva: 2010. július 10.

Beta-128 clone by Pavel Cejka
Beta-128 clone by Piotr Bugaj

Womble: 48K kompozit videó kimenet Great Britain

On Womble's Retro Repair Shack blog is published how to made a composite video output for the 48K (and thus for the 48k+) , which may interesting for a lot of owners.

The job takes up 10 minutes. What you need is a soldering iron and a 4cm wire. Anyway, another 10 minutes to reconstruct the original condition.

The trick is, that Speccy originally sends composite signals to the RF modulator, which is converted to RF signals. This is lead into the TV by the aerial cable, where the TV reconverts it to composite signals. This double lossy converting was necessary in the times of Spectrum, as TVs did not have separate AV input.

The advantage of Womble's picture illustrated modification -beside its simpleness- that it can be done without any psychical damage (drilling, extra screwing). By the way, the original documentation of this modification was released in a 1986 issue of Crash magazine. A very similar modding from Scott-Falk Hühn is also available.

Added: 2010. July 03.

48K composite video output

Alwin Henseler: SRAM replacement for lower 16k The Netherlands

In ZX Spectrum 48K(+) models the memory is divided into two parts. The upper 32K (2x4 ICs) is used solely by the Z80 CPU. The lower 16K (1x8 Ics) is shared between the ULA and the Z80. The errors of these chips often the cause of the non-working Spectrum.

How can the problem solved? It is seems simple, but there is a big problem. The 4116 DRAM memory ICs of Spectrum needs +5, +12 and -5V, and nowadays all available DRAMs work with simple +5V (the original DRAMs can not be bought as new).

So Alwin Henseler in 2009. February introduced the SRAM replacement for lower 16K repair tip, which is replacing the original chips with SRAM module. It has more advantage: first, it has lower consumption, which reduces the Speccy's heat output. And second, also fits fine into the place of the original chips.

The documentation gives detailed description of the modification as well the technical background. Alwin tested it with two types of SRAM chips, all of those were worked (in theory, all 70-150ns access time SRAM module will be fine). Anyway, the idea was based on Miguel Angel Rodriguez Jodar's earlier tip, which was used a SIMM module.

Added: 2010. July 10.

SRAM replacement for lower 16K

Click keyboard Italy

The Italian Electrons beside his another modifications, also take care of the Spectrum. His Click keyboard modification is replacing the keyboard folie membrane with pushbuttons.

This mod is made 'forever' and from outside it is invisible. But while typing, the rubber keys will click under your fingers.

For realizing this modification, you need 40 pushbuttons, plus recommended to build also a reset button at the same time. First you have to take apart the Spectrum. Then you have to drill holes into the centre of the key places of the 'key box'. After you have to drill holes exactly into the same location into a rigid plate. Onto this plate, have to glue the pushbuttons, then also fill the gaps between them with glue for improving stability.

Wiring the pushbuttons to each others can be made by using the keyboard folie membrane as a template.

For last, you have to solder the original connectors to the end of 8+5 wires.

No more steps, put again together your machine.

Added: 2010. June

Click keyboard

ZX Laptopok

Sami Vehmaa's laptop

Two ZX Spectrum laptops also saw the light, both of them are based on the 48K gummy version.

The laptop of srimech.com (Suburban engineering) was built on a Toshiba Libretto 110. The author was built in the gold old gummy keys, and the mainboard and screen remains from Toshiba. So, the main part of the work was to convert the Spectrum's 5x8 matrix to the laptop's 8x13 system. The computer is running Linux, so needed an emulator to feel like a real Spectrum.

Sami Vehmaa' machine is a real ZX laptop: the original machine with a 7" LCD screen, using Compact Flash card as mass storage device. On his website can access the DIY infos, and Sami can support LCD screens for request.

ZX Spectrum +128K

Great Britain

Richard Gellmann's ZX Spectrum +128K project is covers to made a homebrew ZX Laptop with LCD/TFT display, flat keyboard and modern storage devices.

The laptop is based on the ZX Spectrum +2 due its compatibility and nice features (such as RGB output).

The display is a 800x600 resultion TFT screen and .TZX files are stored on MMC card.

The computer will contain two custom chips. First one is ZX10701, which integrates the original ZX8401, PAL 10H8, 74174 and 74157 chips and also supports the NMI ROM.

Second is a ZX10702, which is a PIC16F627 microcontroller. The task of this to decode the signals of the PS/2 keyboard. It is used, because the PS/2 keyboard has numerous advantages comparing the original keyboard matrix. It is easy to replace and using the special keys (for example the multimedia buttons) is also a great feature.

Among the future plans there are a CMOS RAM/RTC and a mini LCD (date/time display, .TZX 'counter' etc.).

The file system is FAT16 and the FGPA-based VGA is a variant of Chris Smith's ULA clone.

Hozzáadva: 2010. július 26.

The Sinclair Shop

The Sinclair Shop is ran by Ian Priddey since 2004 and delivers to every part of the world.

Beside the Spectrum, offers ZX81 and QL accessories, even C64/128 and Amiga parts on sale. Of course, the parts of Amstrad designed Sinclair machines working well with the contemporary CPCs.

Most popular goods are the RGB Scart cables offered for all Spectrum models (thus these are manufactured in three subtypes).

Also spare parts in the warehouse: 48K tape lead, +2 tape and +3 drive belts, as well some types of transistors, diodes, plugs (serial, 9V DC, RGB Video, ZX edge connector). And there is +3 tape lead also.

The homepage is currently under development, presently we can do shopping through EBAY.

Sintech Germany

The German Sintech firm located Filderstadt lead by Thomas Eberle (EBI or FBI).

The on-line shop is handling new and retro computers, consoles and accessories. But the top of the hearth of Thomas there is the ZX Spectrum, which proven by the fact, he is the member of UVS (Users Vote Speccy) coding group and editor of the Scene+ tape and diskzine.

The Spectrum side of the shop offers relatively huge assortment. But it is only the surface, because a lot of goods are common stuff for the PC, Amiga and consoles.

Now pass round the specially ZX Spectrum accessories. Spare parts: TV antenna cable, 48/128K and +3 tape lead, and Scart-monitor cables for all types. Also there are power supplies for all Spectrums. The evergreen 48K and +/128K keyboard membranes offered too.

On the stock the internal and external versions of Proface AT. At the same way can be bought Spectrum keyword sticklers.

Sintech is still waiting for MB-03 pre-orders.

Some another tiny tots: video modulator for better picture quality, and an on/off switch between the Speccy and power supply.

DataServe Retro

DataServe Retro is a single person enterprise, which only handling 8 bit micros. Besides the buying-selling, also offering historical overview, and repairing and maintenance guides on the homepage.

This is a non-profit company. All items, which can be found here, fully restored and tested, so being in much better condition, than anywhere else we can search for.

Alongside of the used hardware, some new parts also available for the ZX Spectrum.

Certainly the 16/48K and 48K+/128K keyboard membranes are accessible. And can be bought the tape leads for these machines too.

Spare tape drive belt for all 128K+2 Spectrums, as well the 128K+3's drive belt can bought, and the tape leads for the last machine is also offered.

The TV antenna cable is fits for all Spectrum models, and also there is RGB Scart cable for 128K+2A/+2B/+3.

Thanks to buying up the old stock, some unused factory hardware is also available: 128K+2 and 128K+2A/+2B power supplies as well 3 inch floppies.


In the 2003 founded Clive.nl primarily was created to put into circulation ZX Spectrum and another Sinclair goods. Later they extended the assortment with Acorn, Atari, BBC, Commodore, MSX, Schneider and Tandy hardware, software, book and magazine section.

In fact, it is a retro collecting group, which sells out the duplicates. The on-line ordered things are posted by priority airmail.

Above the used items, they have some new ones for the Spectrum mostly cables.


The Informantica e-shop founded in 1999 besides supporting current platforms, also has offers for the fans of retro hardware.

In the case of Spectrum, it is the divIIDE+ interface, RGB cables suit for 128K+2 and +3 machines, as well the keyboard membranes of 16/48K, 48K+/128K.

Due to the Amstrad relationship, 128K+3 owners also shop their spare floppy drive belt and the ever rare 3" diskettes.

Some second hand Sinclair items also occur on the Ebay shop.

All Top Notch

All Top Notch is a small family run business manufacturing and selling audio-video cables and other accessories.

For the ZX Spectrum (and ZX81) also trading 2 and 4 meters long TV-cables.