Didaktik Gama 192K/256K ME, Nemesis

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

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

Next year, 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.

Pentagon 128K v2+ 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 said, with some home fixes can be turned compatible with original Spectrums.

Some sources are speaking about further developments (Pentagon v3, v3+ or even v4) but they aren't widespread and nobody trusted the v4's existence so far. Very probably, these improvements were 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.

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 situated 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, working as a publishing house with Solon-Press name.

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 widespreaded 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 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 is quite hard to tune-up, needs much time of home works.

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.

The successor's name is Pentagon 1024SL v1.x (2005.). 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: 384x304 (without border) and 256x192 with conventional 15 colours, but with different colour possibility for every pixel. This graphics mode is called to color-per-pixel (or 16C, 4 Bpp) and very similar to the EGA screen. And colour-clash was eliminated. 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 smoothly, and that is respectful both from the hardware developers and programmer's side.

Professionals regard this machine as 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 mainboard the soonly described Z-Controller is integrated, so contains PS/2 keyboard and mouse ports, and SD card interface. Another new developments: real time clock, VGA monitor socket and USB port.

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 an ordinary 128K Spectrum, the Czech Velesoft is offering two alternatives. With the Pentagon 512 interface easily can anyone emulate the Russian machine. 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.

Scorpion ZS 256 Turbo+

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, KAY 2006 NB

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.

Sprinter 97, 2000

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

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, +2e

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 support of CF cards was not ready, owners could choose the construction of Jose Leandro Novellon or Aitor 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. With these interfaces we will look after.

ZX Spectrum +3s

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

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

Chrome is the "Italian clone", which was developed in 2004 on the basis of SpeccyBob Lite.

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.

ZX-Badaloc

From Alessandro Poppi's ZX Badaloc clone is only one (properly working) prototype exist. Badaloc means "surprisingly fast" by modena slang, referring to the 21MHz high speed of the machine.

The clone is a true all-in-one type. The integrated ZXMMC+ interface is running as a standalone project also, but it will be written later.

The mainboard is compatible with both 48K and 128K Spectrums. Clock frequency is 3.5, 7, 14 and 21 MHz selectable in more steps. Supporting two different video modes: standard Spectrum (256x192) and 320x256x16 hi-res without attributes. Picture can lead out only by a VGA output. Above its built-in 40 button keyboard, also PS/2 keyboard can attached to it. The similarly PS/2 connectored mouse is Kempston Mouse compatible. The joystick port is supporting the Kempston standards. Its Sinclair edge connector is nearly to 100% compatible engineered, at least ZX Printer is working perfectly with it. Size of memory could vary between 128K or 512K, and its content can be hold by the real time clock's battery. (Flash)ROM memory can be vary from 64K to 512K, so beside 48K and 128K ROMs, another 12 clones' ROM available to store. Sound of AY-3-8912 chip has stereo jack output.

ZX-Badaloc FGPA

The ZX-Badaloc FGPA aimed at synthesising the ZX-Badaloc into a Xilinx Spartan-3E evaluation board. It is fully compatible, and has some advanced features. The board can be purchased as it, only necessary to make a small VGA tuning and constructs a small card to get a 42,5MHz superclone with 16/48/128/+2A/+2B/+3 compatibility. All necessary software can be downloaded from Alessandro's website.

Because Spartan-3E only displays 8 colours on the VGA output, have to change some resistors in order to displaying the 16 ZX Spectrum colours.

The small connecting board holds the tape interface, the SD card reader, as well the Kempston joystick compatible interface.

Its operating system is a custom version of ResiDOS. Above the speeds of ordinary Baladoc, can run at 28 or 42,5MHz, and with paging technique, all 64 megabytes are accessible from the DDR RAM module.

ZX Spectrum SE

The purpose of ZX Spectrum SE project was to create a new, second generation Spectrum, which is compatible with the Spectrum 128 and Timex TS2068 machines. The prototype was developed by Jarek Adamski and the British Andrew Owen on the basis of Timex TC2048.

It got 272K RAM, from which 2x64K used in Timex mode, and 128K is used as a Spectrum 128. The production model will contain only 256K RAM.

From the 64K ROM only 2x16K used yet: first is the original Spectrum ROM, and the second is a modified 128 Editor. Later models will equipped with a non-Amstrad owned ROM, but beside that, original Spectrum ROM could be loaded for backward compatibility.

The prototype is emulating TR-DOS and also (semi) Pentagon compatible. The processor is a Z80 at 3.5 MHz, and the AY-3-8912 chip producing ABC/ACB stereo sound in Timex and Sp128 modes. The Kempston mouse port is also present, and supporting an extra fire button, and compatible with Kempston Mouse too.

Above the standard Spectrum screen, supports hi-res and hi-color modes, and also the mixture of this two extra modes.

It is software level compatible with Apple I, Galaksija, Jupiter Ace, ZX80/81 and Videopac/Odyssey computers and consoles.

TC 2048, TS/TC2048 and UK2086 models similarly can tuned up to ZX Spectrum SE.

ZX128

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.

ZXGate

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

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

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

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.

Ant-1024HD

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.

Pentevo

Pentevo (or PentEvo, ZX Evolution) is the modern equialent of the Pentagons (=Pentagon Evolution). The motherboard was presented in the 2009 Chaos Constructions (2009. August 29. - Revision A), and this is also a NedoPC development. Development team members: Vadim Akimov (LVD), Chunin Roman (CHRV) and Dmitry Dmitriev (ddp). The 'second edition', revision B came out in the same year's December 22.

The technical specifications meets the modern clones: Z80 processor on 3.5/7MHz, 4 megabytes of RAM, 512K ROM was built around the Altera EP1K50 FGPA. The board itself is mini-ATX standard, with two ZXBus on it.

Pentagon compatibility is ensured by AY and Covox and also with Beta-128 emulation. There is also possible to load and save from tape magnetofon. Standard PS/2 mouse and keyboard as well IDE connector SD-card slot is symbolizing the modern age.

As video output, RGB composite, S-Video and VGA are all available. Built-in real time clock and RS232-C serial port is also included on the motherboard.

Pentagon 1024SL v2.x and ATM Turbo 2+ compatible.

Frissítve: 2010. május 30.

ZXM-Phoenix 1024

The idea of creating the ZXM-Phoenix 1024 clone was appeared in 2008 in the zx.pk.ru forum.

Its members decided to make such a 'modern ' clone, which uses the technology of 90's, and also looks like it come from the heydays of the ZX Spectrum era of ex-Soviet Union.

Finalization can be connected to Mick (Mikhail Tarasov), but another active members also took part in the process (Caro - Kamil Karimov, Black Cat - Valerij Tkatsuk, Ewgeny7 - Evgenij Ivanov, Keeper - Vimalij Rudenkij, CityAceE - Stanislav Judin, Zloy - Sergei Geracimtsuk). The machine was finally completed in 2009.

The mainboard is a micro-ATX standart with two ZX Buses and a Sinclair edge connector.

It processor is KP1858BM1 and running on 3,5MHz.

Music is provided by AY or YM chips, with a compatibility layout of Penatgon or Scorpion/KAY, as well supporting the Turbo Sound And Turbo Sound FM cards.

Size of RAM is 1 megabyte as default, at this case Pentagon 128, KAY256/1024, Scorpion 256 compatible the machine,. With expanding it to 2 megabytes, Scorpion 1024 and KAY 1024 compatibility simultaneously can be reached.

Video can be lead out using of NedoPC PAL-coder or can be converted to SCART signals too.

The keyboard, mouse, joystick and serial connectors are based on Caro's ZX Multi Card, just as the real time clock.

The IDE-controller is a Nemo-type, and beside the HDDs, also works fine with original, writeable and rewriteable CDs and DVDs,

A board is compatible with the NeoGS soundcard.

Added: 2010. February 06.

Harlequin

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.

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

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!

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.

Beta-128

In the ex-USSR the Beta-128 floppy disk interface became the most dominant mass storage unit along with TR-DOS operating system.

Lot of people think, that Beta-128 is a Russian development and it is something new - although not. It was developed by the English Technology Research in the gold Speccy days as the successor of Beta and Beta Plus interfaces. This version supporting 128K Spectrums beside the 48K models.

Was imported in 1987 into the Soviet Union and engineers rebuilt it from Russian parts. Russian version was firstly released by firm Option in Saint Petersburg in 1989. Soon Russians cracked the original TR-DOS 5.xx and followed with their more advanced 6.xx versions. Details later...

The Beta-128 became de facto standard so much, that it was widespread not as a separated interface, but most clones integrated it into the mainboard (Pentagon, Scorpion).

Very first TR-DOS programmes were disks conversions of old tape classics. The five-minute loading time decreased to some seconds. Because capacity of disks are 640K (with compressing even more, approximately 800K with games), it was usual to made thematic compilations. You could select the games from a menu (for example arcade, sport compilation disks).

Next step was the relatively huge capacity PC-DOS, Amiga games' conversion to Speccy (Prince of Persia, UFO, and Civilization). Some games occupy two disks and Season of Sakura (16C) takes three floppies. Very big step upward in quality of ZX Spectrum games. Such games appeared, which were previously said by the press, it is impossible to make the Speccy version.

Up to 4 drives can be attached to Beta-128, 3", 3.5" and 5.25" types (a:, b:, c: and d: drives).

Capacity is 640K with DD system and 1.7M with the new HD version - although this one is not widespreaded at all. Some simplified versions supporting only two drives, like Scorpion's.

Some companies developed special Beta-128 interfaces for their machines. The Nemo-bus version was mentioned at KAY. The manufacturer of Peters clones also released a special interface for the Contact, but it was also denoted earlier.

An useful function of the interface is Magic Button. It makes snapshot files directly from memory to disk.

Some words are spoken about cracking. Crackers optimised the code of TR-DOS for faster speed, also expanded it with new features. For example, the previously mentioned HD-disk support, the auto-boot function, fast formatting and turbo loading - just to mention the most importants. Latest versions are 6.10E (Mr. Gluk), 6.12 (Power of Sound) and vTR-DOS (developed specially for ATM clones).

HR-DOS is a cracked version of TR-DOS. Interesting, while the functions were expanded with a printer utility, size of the code decreased to half of original. Russian coders must know something!

Beta-128 was cloned also in the territory of ex-Czechoslovakian Republic, although never gained such popularity as D40/D80 systems.

Beside TR-DOS, IS-DOS, DNA OS and a special versions of CP/M can be the operating system of the interface.

CDOS

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 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

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).

To realize 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).

The Palenicek-brothers (JSH - Oldrick, 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, a Kempston, and printer port as well an NMI button. Anyway, the completely hand-made interface was fully compatible with the later serial product.

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+. 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.

The Z80-DMA circuit later also separately implemented as Data Gear, as the device of the previously mentioned graphical accelerator. Currently Velesoft manufactures again this circuit with Data Gear 2007 name.

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. I think, 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.

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.).

The next hardware innovations, MB-HDD(1), MB-HDD2 and MB-HDD3 IDE controller add-ons made my Last Monster (Jan Kucera - LMN/8BC). These based on the internal interface developed by PVL and Tritolsoft. 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.

Flash Utility (I) and Flash Utility II also Last Monster's innovations from 2000 and 2008. First is expands the default 2K EPROM to 32K, the second one can extend it to 64K or 128K (also divided into 32K banks).

Unfortunately, for booting the HDD, needed a boot floppy, which installs the winchester first. To solve this, developed the MB-Maniax team the FlashBOOT update (v1: 2007. November 20.). In order to do this upgrade, first the Flash Utility I or II expansions must be performed, since the original 2K is simply too small.

In January of 2002, first news came out from the successor, the MB-03(+) on the comp.sys.sinclair newsgroup. This news was announced by Jan Werner, one of the owners 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 will arrive with these features in the future.

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 terminated.

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.

+D

+D (or alternatively PlusD) floppy interface is not a new development like the Beta-128. But opposite that, it had a nice carrier in the classic Spectrum times, along with its more complex achestor, the DISCiPLE.

The interface was originally engineered by Miles Gordon Technology, and its further development was built into the SAM computers. The system uses 3,5" DD disks with 780K capacity. Loads a 48K programme in 3,5 seconds.

Also offers two more extras as a Centronics port and an NMI button. After MGT was bankrupted, Datel continued distributing this system.

After the Spectrum-era, documents became public domain, so the interface is available both in DIY-kits or as ready made circuit. It is compatible with 16/48/128/+2 machines, but unfortunately not with the latest Amstrad designed +2A/B and +3.

The interface can be obtained for example from Spectrum Profi Club in Cologne in Germany. The English RWAP Software is also offering this interface. With limited numbers, they can also offer single or double floppy disks with internal power supply. The Spanish Droy also developed an another version. For the easier expanding possibilities he divided into two the original circuit. At the same time, cutted down the manufacturing costs eliminating the pricy PCB work. The interface, the floppy drive and the power supply is sitting inside the same box, on which he mounted the NMI and reset buttons.

Külső +3 floppy interfész a +2A/B gépekhez

Philip Mulrane in 2002 created his external +3 floppy interface for +2A/B, with which can turned the Frankenstein like +2A/B cassette machines compatible with the +3.

The idea is based on Peter Simandl's interface, who mounted this card inside the machine. It was released in the ancient times, but Peter very smartly published it on his website.

Opposite of the original, Philip redesigned the circuit as an external card.

It handles two drives, and even compatible with the 3,5" ones. At one stage, the author was also planned to integrate the +3e's hard disk controller, but finally it was abandoned.

Certainly, all documentations are accessible from the website, and we can also get tips of buying the ingredients.

SMUC

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

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, diwIDE, divIDE 512

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 Lubomir Blaha (Tritolsoft) and Pavel Riha (PVL) from 1999. This one is an internal variant, which is also the first version of MB-HDFD built into the MB-02+.

For the authors, Matsoft brought the 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 Dron. With the HDD_patch utility 2 megabytes of virtual disks are used. Later version of the program is also support 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 (Pavel Cimbal). 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. Pavel's next and final prototype was DivIDE 42r4.

The first public version was DivIDE 57, mostly spread among the Czech colleagues from August 2002.

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

The most widespread model, DivIDE 57c is the same, but on the board the jumpers are signed with different characters.

In 2007 was released the R"GAL modification. The new chip is also even replaceable with the old R_GAL one. It can control two custom ROMs, which are paged into the Speccy's original ROM.

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 (2006. December 22). 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, ZXVGS and ESXDOS.

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.

The Dutch Ben Versteeg also producing DivIDE 57c, can be ordered through his blog or E-Bay shop. The English Papaya Labs and the German Sintech are also selling this interface, as well the CF-IDE adapter. In smaller quantity, can be ordered from the Czech Noby also.

The Polish Lotharek also offering a DivIDE 57c clone, in flashy, red colour PCB. We can surely name it to a clone, as differs in some point from the original card.

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.

Megadrive 256

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

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.

ZXMMC és ZXMMC+

Alessandro Poppi, the author of ZX Badaloc clone has two another development: the ZXMMC and ZXMMC+ interfaces. Although only a "+" sign difference in the nomination, there are a lot of differences between the two cards: certainly the plus version is more complex.

The ZXMMC card can plugged into the Z80 socket of 128K+2A/B and +3 machines (Theoretically compatible with all Spectrums, but there is psychical problems in building in). It is connected to the development of ZX Badaloc clone and it is a SD/MMC card reader-writer. Transfer speed is 218KB/sec at 3.5MHz. Not only with the Spectrum, but compatible wit all Z80 based machines. The interface supports two cards, but there is only one port on the PCB. Who really want, can solder the second port onto the top of first. It has two subgenera: the basic version only capable to read and write. The full variant also contains Kempston joystick and RS-232C ports.

The ZXMMC+ is fairly extends the possibilities of the Spectrum. Above the extras of ZXMMC full version, it has 512K battery backed RAM and same size of Flash ROM. Got NMI and reset buttons and a thoroughgoing edge connector.

ZX Spectrum +3e is supporting these devices.

Interface 1-bis

The aim of Dan Antohi's Interface 1-bis card to enhance the communication and (mass) storage capabilities of ZX Spectrum. As the name shows, another purpose was to keep the Interface 1 compatibility.

The operating system sits in the 32K SRAM, and it handles .TAP files and can save in .Z80 file format. Beside, contains a printer controller as well the author was corrected some original ROM bugs.

The IDE controller can manage 32 megabyte partitions. The parallel port is capable of printing 32 or 64 columns of text and graphics as well.

With the network possibilities of the card, the Speccy can be connected to a PC, so mass storage devices and printers may shared.

The Kempston joystick port is also placed.

First prototype was made in 2000. The present version in an electrical optimized one, without any new extras. The initial operating system remains intact but in a radical smaller size.

The full documentation is accessible from Dan's webpage.

Z-Controller

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.

ZX Multi Card

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.

ProfROM

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

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

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.

YAZSAKI

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.

Covox és Soundrive

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.). 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.

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 end 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.

Czech/Slovakian Covoxes are made for playing three channel music, opposite of the Russian four channel devices.

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. 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.

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 AY/YM extensios

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, 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!

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.

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. Sound Power group released Turbo Sound Editor, other programs do not support this enhancement.

NedoPC-turbo sound similar to previous: a dual-AY with twin ports. With a micro-switch can be activated the second AY/YM chip. The name "Turbo" is very fits for in this case: this switch is very reminds us to the old 286's Turbo mode switch Executors of this sound enhancement are the designers of ATM Turbo 3 clone, the NedoPC group. It has more subgenerations such as Turbo Sound A, B, C and FM. C version already supports both normal/turbo speed machines as well old and new software. FM version is incorporates two YM2203 chips, and it is compatible with old AY and TS software and uses 12 channels. Unfortunately it is only compatible with normal speed Spectrums. As the chip is compatible with YM2612, so Sega MegaDrive and Genesis consoles' music can be played, and we can also compose Sega music on the Spectrum with the FM card! NedoPC is selling these enhancement in small series, but all technical documents are freely available for those who wants to assemble by themselves. On the various demo parties and another occasions, Turbo Sound cards were gifted as prizes, in order to facilitate the widespreading of the device.

VeleSoft also produced his own version. Turbo Sound Easy only contains one AY/YM chip (all other variants two). The card uses the computer's built-in chip as a primary music chip. Also has a Philips SAA1099 for emulating SAM Coupe sounds. So sound is 12 channels. Fully compatible with the NedoPC variant.

At the same time, 6 channel editors and players were appeared, for example Turbo Sound Player, Vortex Tracker II or a special version of Protracker. Even, 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.

General Sound 128/512, NeoGS

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 1997-98 (Saint Petersburg), but Scorpion and Nemo also engineered their own versions.

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 includes 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.

NedoPC Group was developed 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.

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 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

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

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.

Spectranet

The goal of Spectranet Ethernet interface is to put the Spectrum on-line again. This was realised in the past by the Prism VTX-5000 modem, the ZX Interface I network and the help of RS-232C port.

These methods are now outdated, as serial ports are begin to disappear from PCs, and Interface I works only in its own network system.

The author, Winston's purpose to create such Ethernet Interface, which is compatible with Interface I, divIDE(+), and the Kempston and another joystick interfaces. Another aim to be compatible with both Sinclair and Amstrad designed models.

Which is surely realised: the small sized compact PCB with a thoroughgoing port.

By his plans, the series production pieces will cost less than 30 pounds.

On the author's blog, we can trace every steps of the hardware and software development illustrated with numerous photographs.

SpeccyBoot

Patrick Persson successfully solved the booting of ZX Spectrum over on Ethernet network. The 'packet', which consist of hardware and software parts 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, 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.

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 30 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 15 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.

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).

GMX

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

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.

Velesoft 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 bugfixes board with Kempston and Fuller joystick support.

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

The soon introduced Dutch Ben Versteeg begin the small series production of Kempston Mouse Turbo. In the package, beside the interface, customers are also will get English language instructions as well an optical scrolling mouse (if Ben have them on the shelves).

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

ZXKit1 VGA&PAL board

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.

Jarek Adamski 's extensions

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 ancestor 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

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

In 2006 developed a 48K+ internal keyboard adapter. 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. 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.

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.

Dr. Beep's extensions

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

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

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 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, his divIDE upgrade and the PS/2 ported Proface AT were already introduced.

Sound Mixer for Turbo Sound Easy is a mixer, which control the Turbo Sound ABC/ACB, SAA stereo and beeper channels, so a 12+1 channel mixer.

With the Pentagon 512 interface the 128K Spectrum can be turn compatible with the famous Russian clone. Opposite of its name, memory can be not only 512K, but expandable to 1 megabyte. It has 128-512K Flash EPROM memory for holding the operating system and utilies. Pentagon 48/128/256/512/1024 compatible.

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...

Data Gear was initially engineered as the part of MB-02+ interface. Just to remember: originally its task was to speed up the access of HD disks, but the additional power is used as hardware accelerator nowadays. Its main advantage to produce Multicolor effects without vibrations. In 2005 and 2007 was pushed into production one-one series.

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.

Updated: 2010. January 30.

Pera Putnik's extensions

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.

Cygnus' extensions

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.

Droy's extensions

Droy living in Spain since 2002 surprised with numerous inventments the Spectrum community.

Supposedly, he must be an Interface II fanatic, as lots of his work in connecting to it.

His own Interface II clone (without the joystick ports) consist of two wired ISA connectors. Also made game cartridges with enhancing the original conception. On original cards only 16K games can stored and played. He was improved it to one 32K game or selectable two 16K games.

ZX-Flash Card is a further more developed device. With a 512K capacity card we can choose from 10 pieces of .SNA files, sparing the more minutes 48K loading times.

Engineered a new PlusD interface too, but that was mentioned earlier.

The IMAR-3 PC-AT keyboard controller is his creature too, which gives the possibility of connecting AT or PS/2 standard keyboards. Sadly, only 48K and 48K+ compatible. But thanks to the thoroughgoing edge connector, another peripherals easily can attached to it.

Some methods of replacing the dead keyboard membranes also come from him.

Paul Farrow bővítései

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 Droy, 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 three separate generations from the cards: ZXC1, ZXC2 and ZXC3. 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, the second got goldened to improve elelectric contact (otherwise, the two PCBs are identical).

ZXC2 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 most current version is ZXC3, 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.

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

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.

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.

Gondos Csaba's extensions

Gondos Csaba (GoCom, Gondos Computer Communication) is the main constructor of Sinclair.hu and also a radio amateur. His first interesting development is the Smartmedia interface 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.

Another two novelties, the G-Tech analogue joystick interface 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.

Another developments: reducing the power consumption in more steps and reconstructing the keyboard membrane from micro switches.

Scott-Falk Hühn's extensions

Scott-Falk Hühn German tuningmaster offers some smaller-bigger tips for turbocharging the 48 and 128K Spectrums.

Similarly to Paul Farrow and Droy, he also made Interface 2 cartridge clones. In the same way used 512K Flash-EPROM, giving opportunity of using 32 different 16K ROMs, but currently only 16 of that are used. Choosing is done by a manual selector. Not only games, but also various ZX80, ZX81 or test ROMs can be loaded.

For the rubber keyed mate offers composite video output and reset button.

Improving of 128K video output is done by desoldering a capacitor and a resistor (quite surprisingly, they are even missing in the 128K+2). Of course, the picture of 128K+2 is also far from the perfect, he was doctored the problem with part replacement. This improved picture quality was further improved with separating the audio signal from the video output.

Certainly, the 128K sound was not too very perfect for him: the beeper was too loud, and AY music was too quiet, so made a small circuit to solve the problem. And the 128K+2 also could not avoid this modification, here the noisy tape loading voices also were quieted.

According to his needs, mounted a third RS-232C/Midi/Keypad port into the machines.

With a selectable 64K EPROM, beside the 128K+2's own ROM, the original 128K ROM is also available for compatibility reasons.

Finally, re-wiring of the nonstandart 128K+2 joystick ports are also done.

On the picture all 128K+2 modifications seen.

Ben Versteeg's extensions

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.

Jose Leandro Novellon's extensions

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's extension

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

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.

Hw.speecy.cz

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.

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.

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 imple 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.

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.

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.

Ik0n's ZX Spectrum +3e^2 machine is the further development of ZX Spectrum +3e with Pera Putnik's CF-interface.

First, you have to build the ZX Spectrum +3e with the two ROM sets.

This is followed by the CF-interface. Ik0n suggesting to realize it with a separate CF-IDE adapter, as the original CF socket is too small for homebrew fabrication.

Updated: 2010. May 07.

SinDiKat

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.

The next innovation is to enhance the ZX Spectrum +3e with DivIDE support, this is the ZX Spectrum +3e^2.

From the +3e enhancements, Ik0n choose the 8 bit Pera Putnik CF interface due its simplicity with a single change. Since it is difficult to solder the CF slot connector because of small size, so choosen to solder an IDE connector. The CF-card is connected via a separate CF-IDE converter.

The next step is to build in the suitable double-sized EPROM. The first position is the +3 mode (DivIDE) in the other, the +3e ROM can be used by default.

The CF card slot is placed under the already changed 3,5' floppy drive.

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.

Hozzáadva: 2010. május 22.

Lotharek' enhancements

The KempAY interface is Lotharek's first own development, of which realization started in 2009. November. This is a combined card, incorporating a Kempston Joystick Interface and an AY-interface. The Kempston part is consist of a single connector. The AY-sound is 128K Spectrum compatible. It contains a thoroughgoing Sinclair edge connector and a 3,5mm jack tunnel. The most time-consuming part of the development was to integrate into two GALs the originally 5-6 chips design. Fortunately, Yerzmey, the AY-magician of Hooy Program helped him a lot. As a pure PCB or as a ready assembled card can be ordered. The detailed assembly instructions on the website is available.

About his DiIDE 57c clone, USB HxC and SDCard Hxc Floppy Emulator mentioned several paragraphs earlier.

Added: 2010. May 02.

48K composite video output

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.

SRAM replacement for lower 16k

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 modification, 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). Testing machines were Issue 3B and 4B.

Added: 2010. július 10.

Click keyboard

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.

Hozzáadva: 2010. július 15.

ZX Laptopok

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

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

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.

Clive.nl

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.

Informantica

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.