Retro Computers - ZX Spectrum +3 - Retro Computer

ZX Spectrum +3
The final lump from Sugar is just not quite sweet enough.

Ahh, the ZX Spectrum plus 3. This was the final incarnation of the famous ZX Spectrum machine manufactured by Amstrad. It was released onto the UK market in 1987 and is generally heralded as the finest of the ZX series. (It is generally noted that after 1987 the ZX Spectrum and it's classic games scene began a slow decline as the new 16-bit machines took over.)

The Sinclair Spectrum +3 was the successor of the ZX Spectrum +2 which had been marketed roughly one year earlier. The Spectrum +3 can be considered as a 'mix' between the Spectrum 128 and the Amstrad CPC 6128. Like this machine it has 3’’ disk-drive built into the right hand side of the case and a 'proper' full-stroke keyboard, just like the CPC 6128.

As on the Spectrum +2, two BASIC versions were implemented:

• 48K BASIC to remain compatible with the original Sinclair ZX Spectrum 48K - which allowed the loading of older software and those all important classic games
• 128K BASIC which was already introduced with the Spectrum 128.
  

As with the others 128K models, and due to the limitations of the Z80 CPU (which can only address 65536 bytes), the 128KB of RAM is not directly usable (unless with bank-switching routines) but can be used as a RAM disk (drive M :).

So, now that we've got all of that out of the way, we know that the big change is the built-in 3’’ disk drive, (which was exactly the same as the CPC-6128’s drive). The operating system was imaginatively titled +3DOS and was developed by Locomotive Software Ltd.

Locomotive Software also went full steam ahead and conceived the CPC Basics and OS. We can sense a pattern emerging here, the +3DOS is very close to the CPCs disk operating system. The Amstrad FD-1 external drive can even be used with the Spectrum +3 as a second disk drive by connecting it directly to 'DISK B PORT' at the back of the system.

The Spectrum +3 was (and by many still is) considered the ultimate Spectrum model as it gathered all of the good points of the previous spectrum machines:

• 128KB
• Convenient full-stroke keyboard
• 3’’ built-in disk drive
• RAM disk
• More interfaces than R2D2
• Existing huge library of computer games (both text adventures and arcade games) - many of them already classic games

Sadly, this machine was launched just a little too late. The Atari ST and the Commodore Amiga, (new, powerful, hooked into EVERYTHING. They decided the Spectrums fate in a microsecond) were becoming more popular and both used disk drives as a storage medium.

The Spectrum + 3 had no advantages over these machines apart from existing software library and price. The C64 and Spectrum rivalry had shifted and the competition was now on between the Atari ST and the Commodore Amiga. Shelf space for the new Spectrum was limited.

The +3 was the last official Sinclair Spectrum model ever made, apart from the +2A and +2B models which were launched a little later, but these were just a revision of the +2 model which was already on the market.

Many people did not want to spend money to buy existing games on disk, and stuck with cassette versions of games (in a smart move a standard tape deck could be connected to the +3).
Many of the classic games were only available on cassette and did not get a disk release either. Also, like the +2, it had that 'Amstrad' feel to it, you just knew it was not one of Uncle Clive's machines. (It was still a decent looking machine though, the built in disk drive was quite snazzy.)

Consequently the +3 never reached the heights of its predecessors. Still, the +3 was a fine machine to bring the Spectrum era (and a certain era of arcade gaming) to a close.

Give it a round of applause for helping to usher in the 'built in disk drive' era. A fine retro computer.

To see further information about games, developers and software houses for this machine, go to Spectrum Games

For more general Speccy info and vids go to Sinclair ZX Spectrum

We recommend trying to pick up one of these machines.
Look at computers for sale online or even locally.

If you don't want to get hold of the real hardware then try and download an emulator and download those classic games. Alternatively you could try and play them online.

MACHINE NAME: ZX SPECTRUM +3
MANUFACTURER: Sinclair
MACHINE TYPE: Home 8-Bit micro (a premier computer games machine)
COUNTRY OF ORIGIN: United Kingdom
RELEASE YEAR: 1987
BUILT IN LANGUAGE(S): 48K Spectrum BASIC (compatibility mode) and 128K Spectrum ZX+3 BASIC, integrated with +3 DOS
KEYBOARD: Full-stroke keyboard, QWERTY, 58 keys, arrow keys
CPU: Zilog Z80 A
SPEED: 3.5469 MHz
RAM: 128 kb (8 x 16k pages)
ROM: 64 kb (4 x 16k pages)
TEXT MODES: 32 x 24
GRAPHIC MODES:256 x 192
COLORS: 8 with two tones each (normal and bright except Black which was only in 1 tone)
SOUND: 3 channels over 8 octaves (Yamaha AY-3-8912 chip)
SIZE / WEIGHT: 440 x 174 x 50 mm / 1,65 kg
I/O PORTS: Really great - UHF PAL TV port, Serial interface (RS232) port, Parallel Printer port (8 bit), Auxiliary interface port, RGB Monitor (and PERITEL TV) port, MIDI output port, Two Joystick ports, Audio Out/Cassette port, Second Disk Drive port, Expansion I/O port (full Z80 bus)
BUILT IN MEDIA: 3'' Hitachi Floppy Disk Drive, single sided (40 track, 9 sector, 512 bytes/sector), CP/M compatible structureVolatile RAM Drive
OS: +3DOS
POWER SUPPLY: External PSU (5V @ 2A, +12V @ 700mA, -12V @ 50mA)Same as Spectrum +2A/B PSU
PRICE: £249 (UK 1987)

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Retro Computers - ZX Spectrum +2 - Retro Computer

ZX Spectrum +2

Oh Sugar, Alan's trading Spectrums!

The ZX Spectrum +2 was the first Spectrum machine manufactured by Amstrad.
The bearded entrepenuer had acquired the rights to all things Sinclair during 1986. I wonder if he told Uncle Clive he was 'fired'?

Anyway, it is not suprising that the Spectrum +2 is very similar in shape and functionality to the Amstrads own 8-Bit machine, the Amstrad CPC 464.

It was a kind of hybrid mix of the ZX Spectrum 128 and the CPC 464, which actually resulted in a pretty decent machine - and of course a classic games machine.

Even though it used several features of the CPC 464, such as the built-in tape recorder (snappily named and very eighties sounding the 'Datacorder') and a good full-stroke keyboard, it is above all an improved Spectrum 128.

The sound chip used in it was still the well-known Yamaha AY-3-8912 which was the sound chip of the MSX computers, Oric computers, and the Atari ST series. Many other computers of the 80’s used this well known and decent sound chip. Mr AY Yamaha was a popular piece of silicon.

As on the ZX Spectrum 128, two versions of BASIC were implemented:

• 48k BASIC to remain compatible with the original Sinclair Spectrum (and many classic games)
• 128k BASIC which was already introduced with the Spectrum 128

There was still a calculator mode in the start-menu but the 'Tape tester' option of the 128 had been removed since the tape-recorder was built-in.

As with the other 128K models, and due to the limitations of the Z80 CPU which can only address 65536 bytes, the 128KB RAM was not directly usable (unless used with bank-switching routines), but could be used as a RAM disk.

There were several versions of the Spectrum +2:
The Spectrum +2 (grey case) which had a motherboard nearly identical to that of the 128 Spectrum +2A and +2B (replete in a black case - really how it should be) which were simply Spectrum +3 computers with a tape-recorder built in instead of the disk drive. These models motherboards were quite similar to that of the +3, which is not surprising in the least.

The difference between the +2A and +2B was mainly due to a move in production from Hong Kong to Taiwan. The first ROMs developed by Amstrad for the + 2 model caused compatibility problems with the old Spectrum software, so they altered a few things in later ROMs to fix this slightly annoying issue.

The main advantage of this machine over a ZX Spectrum 128 was the built in 'Datacorder'. You had no need for that old tape deck anymore, and you no longer had to fiddle with volume controls and tone settings. Just stick the tape in, choose the load option (or type Load"" if you're in 48 mode) and press play. Even hyperloaders were more reliable with the +2 tape deck (sorry Datacorder). This made it (like all other Spectrums) a classic games machine.

Many folks trader their rubber-keyed models in for one of these, by this time your aged 48K model may have suffered from keyboard problems, as the membrane was known to perish after periods of intensive use. Especially if used it to play Daley Thompsons Decathlon without a joystick. It was good to have a 'proper' keyboard (it also helped with playing games), especially if you were a decent typist.

The only thing that put some people off was (unfairly) the fact that it was an Amstrad machine. The grey ones had lost the 'Spectrummy' feel, and even the +2A and B with the traditional black case failed to recapture that Spectrum charm. Still, you could use it with that large back catalog of software you had, which ensured the Spectrums longevity for another few years.

Gentlemen, trim your beards into a 'Sugar do', and hail the Spectrum +2! A fine retro computer.

To see further information about games, developers and software houses for this machine, go to ZX Spectrum Games

For more general Speccy info and vids go to Sinclair ZX Spectrum

We recommend trying to pick up one of these machines.
Look at computers for sale online or even locally.

If you don't want to get hold of the real hardware then try and download an emulator and download those classic games. Alternatively you could try and play them online.

MACHINE NAME: ZX SPECTRUM +2
MANUFACTURER: Amstrad (Under the Sinclair name)
MACHINE TYPE: Home 8-Bit micro (classic games machine)
COUNTRY OF ORIGIN: United Kingdom
RELEASE YEAR: 1986
BUILT IN LANGUAGE(S): Sinclair Basic (48K compatibility mode) and Sinclair Basic 128K
KEYBOARD: Full-stroke keyboard with 58 keys (same layout as the ZX Spectrum+)
CPU: Zilog Z80 A
SPEED: 3.5469 MHz
RAM: 128 kb (8 x 16k banks)
ROM: Spectrum +2: 32 KB Spectrum +2A/B: 64k
TEXT MODES: 32 x 24
GRAPHIC MODES: 256 x 192
COLORS: 8 with two tones each (normal and bright apart from Black which was only available in one tone)
SOUND: 3 channels, 8 octaves (Yamaha AY-3-8912)
SIZE / WEIGHT: 44 x 17,5 x 5,5 cm / 1,525 kg
I/O PORTS: Plenty. UHF PAL TV port, Serial interface (RS232) port, Parallel Printer port (8 bit), Auxiliary interface port, RGB Monitor (and PERITEL TV) port, MIDI output port, Two Joystick ports, Tape/Audio Out, Expansion I/O port (full Z80 bus)
BUILT IN MEDIA: Tape Recorder (Datacorder)
POWER SUPPLY: External PSU Spectrum +2 = 9v DC, 2.1A (centre polarity = -ve), Spectrum +2A/B = 5V @ 2A, +12V @ 200mA, -12V @ 50mA (Spectrum+3 PSU can be used)
PRICE: £200 (UK 1986)

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Retro Computers - ZX Spectrum 128 - Retro computer

ZX Spectrum 128
Now we got more memory and decent sound. Bring on the arcade games!

The ZX Spectrum 128 was an 8-Bit personal home computer released by Sinclair Research Ltd in 1986 (in conjunction with their Spanish distributor Investrónica). It had been referred to during development as the 'Derby' before it was finally given the 'ZX Spectrum 128' moniker. Apt I suppose since it had a (then) massive 128KB of RAM installed.

Modelled on the ZX Spectrum + , it was a similar machine with a few important enhancements. The keyboard was slightly better, having a crisper touch and a higher level of responsiveness. It had more RAM - now sporting a large 128KB compared to it's 48KB younger brother.

But perhaps most importantly - the machine had been blessed with a decent sound chip - the AY-3-8912 (which was also present in Amstrad CPC machines). At last, programmers had something decent to work with on the sound front - and those all important arcade games could be blessed with true three channel music and sound effects!

Spectrums were already extremely popular, and this machine was cleverly designed to take full advantage of the Spectrums existing software (which already had 1000's of arcade games, platform games and text adventures) and hardware base. (Are you listening Commodore Plus 4 designers?)

Anyway, when the machine was switched on it would greet the user with a menu.

The options were displayed as:

• "Greetings Professor Falken"
• "Tape Loader" - in case you can't guess this was to run programs from tape
• "Calculator" - to enter numerical operations without having to type PRINT. This was a very handy feature
• "Tape Tester" - to test the input level of the tape recorder. Another handy feature
• "BASIC 48" and "BASIC 128" - this allowed you to run it in '48 mode' for ZX Spectrum 48 compatiblity, or to use the new features of '128 mode'.

These new features in the 'Basic 128 mode' had a full screen editor and the user could enter Basic commands letter by letter instead of pressing key combinations. You had no need for Mister Miyagi to train you in Speccy keyboard kata anymore now that this mode of programming was available. The up side to this was that it made Mister Larusso very happy.

It also had new keywords to use the extended memory as a RAM disk (unless bank-switching routines were utilized), and to handle the new sound chip and the MIDI out socket. This was an exciting change when coming from classic Speccy programming.

It managed to be popular due to being competitively priced, retailling at £179.95 on release. This was good value for a machine with 128KB and full MIDI capability - not to mention an already large library of classic games, utilities and hardware.

Many existing games were re-released as a '128' version, usually featuring new menu music and better sound effects. The main advantage was being able to load larger computer games (such as Combat School) into memory in one go - no need for loading each portion of the game in section by section. This was a real boon.

Sinclair had also managed to increase the CPU speed slightly, with the Zilog Z80 A running at 3.54690 MHz, but the speed difference was only marginal.

The machine did have the same graphical 'limitations' as the 48K version (the famous attribute clash), and was technically identical in this respect.

Still a cool looking piece of kit, the new design was as nice to look at as the previous models. Sinclair machines always did look good.

Still, it was a good 8-Bit machine, and was the last of the real 'Sinclair' Spectrums. Sigh.

Kneel before it and acknowledge your thanks to the last of the 'Sir Clive' machines. A fine retro computer.

To see further information about games, developers and software houses for this machine, go to ZX Spectrum Games

For more general Speccy info and vids go to Sinclair ZX Spectrum

We recommend trying to pick up one of these machines.
Look at computers for sale online or even locally.

If you don't want to get hold of the real hardware then try and download an emulator and download those classic games. Alternatively you could try and play them online.

COMPUTER NAME: ZX Spectrum 128
MANUFACTURER: Sinclair
MACHINE TYPE: Home Computer (classic games machine)
COUNTRY OF ORIGIN: United Kingdom
RELEASE YEAR: January 1986
END OF PRODUCTION: December 1986
BUILT IN LANGUAGE(S): Sinclair Basic
KEYBOARD: QWERTY keyboard
CPU: Zilog Z80 A
SPEED: Slightly quicker than the 48KB model running at 3.54690 MHz
RAM: 128KB
ROM: 32KB (16k 48k Basic + 16k 128k Basic)
TEXT MODES: 32 x 24
GRAPHIC MODES: 256 x 192
COLORS: 8 with 2 tones each (normal and bright except for Black which only had one tone)
SOUND: 3 channels over 7 octaves provided by Yamaha AY-3-8912 chip
SIZE / WEIGHT: 320 x 150 x 45 mm
I/O PORTS: Expansion bus, Numeric Keypad, RS232 / Midi Out, Video RGB, Tape (1200 baud)
POWER SUPPLY: External PSU 9v DC, 1.85A
PERIPHERALS: ZX printer, ZX microdrives, Joystick Interfaces
PRICE: £179.95 (UK 1986)

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Retro Computers - Original ZX Spectrum - Retro computer

Original ZX Spectrum

An 8-Bit rainbow worth more than any pot of gold.

The ZX Spectrum was an 8-Bit personal home computer released by Sinclair Research Ltd in 1982. It had been referred to during development as the ZX81 Colour and ZX82, before it was finally given the 'ZX Spectrum' moniker.

This was an apt name as it highlighted it's colour display, compared to the black and white of its predecessors, the Sinclair ZX80 and ZX81. The Spectrum was initially released in three different models, ranging from the entry level model with 16KB of RAM, to the more popular 48KB model and the ZX Spectrum + (which also had 48KB of RAM).

The Spectrum was among the first 'mainstream audience' home computers in the UK, similar in significance to the Commodore 64 in the USA (Although the Commodore 64 was also a very popular machine in the UK).

The introduction of the ZX Spectrum led to a boom in companies producing software and hardware for the machine (computer games really took off on it), the effects of which still resonate on and on throughout the 21st Century. Even now classic games and retro arcade games are popular, partly down to this machine.

It managed to reach this mainstream audience through clever pricing. The cost of the machine was attractive to potential buyers, by 1984 the 16K model was retailing at £99, whilst the 48K was going for £125. A snip when compared to many other machines of that era.

The Spectrum was a far superior machine than the ZX81. Most people opted for the 48K model, so you already had alot more RAM to play with. It also had 8 colours (with a 'brightness' level so you effectively had 15 colours plus black) and finally for Sinclair, a sound generator! Okay, so the sound was nothing special (a one channel beeper) - but something is better than nothing right?

Games developers actually managed to make it produce interesting sounds effects and music over the years, with covertape arcade game Hyperactive being a good example of what could be acheived.

The machine did have some graphical 'limitations' however. The image resolution was 256 X 192. Now, to conserve memory, the colour was stored separate from the pixel bitmap in a low resolution 32×24 grid overlay, corresponding to the character cells. An 'attribute' consisted of a foreground and a background colour, a brightness level (as mentioned above) and a flashing 'flag' which when set, caused the two colours of a graphic to swap at regular intervals.

Unfortunately this method of displaying characters etc led to what was dubbed colour clash or 'attribute clash'. Some truly bizarre effects in the animated graphics of arcade games would be seen over the next few years.

This problem became a distinctive feature of the machine and an in-joke among Spectrum users and advocates of other systems would laugh and point at it. Other machines which were available around the same time did not suffer from this graphical problem.

The machine's Sinclair BASIC interpreter was stored in the ROM (along with some fundamental system-routines) and was once again written by Steve Vickers on contract from Nine Tiles Ltd. It was a decent version of BASIC, with simple routines and commands allowing amatuer users to draw shapes and create graphical images with relative ease. Good old Steve must have had a sense of humour with the debugger informing you that the line of code you had just entered was 'Nonsense in BASIC'. Great stuff.

Apart from the attribute clash problem, the Spectrum also had another feature which was laughed at by all of those un-cool non Spectrum users. It was the chiclet keyboard which was mounted on top of a membrane in a similar fashion to calculator keys. Because the keys were made of rubber it was dubbed the 'dead flesh keyboard'.

When each key was pressed an audible 'click' would be heard through the beeper, which was actually pretty cool when you were on a programming roll. Each key was also marked with BASIC keywords (in a similar vein the the ZX81) - so pressing 'G' would insert the BASIC command GO TO. You would use shift, symbol shift etc to switch modes and program BASIC commands.

It was difficult at first, but once you had mastered this method of 'typing', you're hands would be magestically flying over the keyboard with so much grace and flair any onlookers would have though that you'd been trained by Mister Miyagi.

One Step Beyond:
Despite the machines slight flaws, it went on to be more popular than me on a night out. Games developers churned out titles for the Speccy (as it was now fondly known), with many quality titles available. It is now known as one of THE classic games machines of the 1980's.

There were also plenty of peripherals to be had:

• A printer
• Joysticks (Kempston joysticks being the most popualr)
• Micro Drives (Despite being reliable and capable of storing a massive 80KB worth of data they never took off)
• Fuller Box (Improved sound and music - very useful in arcade games)
• Interface 2
• Speech synthesisers (Does anyone remember Currah Micro-speech?)

As the years rolled by, developers really started to push the machine further than the theory of relativity should allow. Music that sounded like 'two channel' sound was appearing in arcade games (Check out the Ping Pong menu music by Joffa Smiff). Highly detailled colour graphics moved smoothly across your screen - better than anything Commodore or Amstrad could muster. Clever developers even managed to write games without any attribute clash. True genious.

Of course the arrival of the Spectrum + in October of 1984 gave users a 'proper' typewriter keyboard. But people will fondly remember names such as Joffa Smith, DK Marshal, Mike Singleton, Keith Burkhill, Mike Follin, the always uber-cool sounding Bo Jangeborg and of course, Matthew Smith. Hold these names in reverance folks.

By 1986, developers were really becoming accomplished at writing arcade games and text adventures for the Speccy. It was good timing for an improved model to be released. Uncle Clive and his Spanish buddies at Investrónica treated us to the ZX Spectrum 128 in January of that year. Based loosly on the Spectrum +, it had a proper keyboard (it was nice to have a Space bar), and three-channel audio via the trustty AY-3-8912 chip.

Due to this it also had MIDI compatibility, an RS-232 serial port, an RGB monitor port, 32KB of ROM including an improved BASIC editor, and an external keypad. On top of this you now had a whopping 128KB of RAM.

The extra memory was handy as some larger computer games required to be loaded in from tape in 'portions' - as you completed one part of the game, you would load the next part in. If you had one of these new machines, the whole game could be loaded in one go. Marvellous!

The Spectrum 128 was the last of the 'Sinclair Spectrums' as Amstrad bought the rights to the machine and would produce them for the next few years.

The Spectrum 128 (and it's later models produced by Amstrad) gave the machine longevity which allowed it to live on into the early 1990's. Only the C64 had a similar life span. It is unlikely that any other machine will live as long again.

Despite there being other machines that were in some ways superior, none had the charm of the Spectrum. Looks wise it was probably best of the bunch. The original 'rubber key' models were compact and very stylish. The black plastic case with the greyish blue keys and rainbow stripe along the bottom right corner was a right looker. The Sinclair logo was printed in a nice font too.

Whereas other machines perhaps seemed a bit more 'professional' (- look at the Beeb), character oozed from the Speccy in spades. The machines character led to one of the infamous machine v machine debates of the 1980's.

An intense rivaly developed between the Commodore 64 and the ZX Spectrum which has gone down in the annals of geekdom. It truly is the stuff of legends. Arguments would run into the wee small hours covering which latest arcade game was the best, smooth yet blocky sprites against detailled single coloured characters. Scrolling speed, keyboard responsiveness, playablility etc etc.

These sort of things made computing real fun back in the 80's. I'm wiping a tear from my eye just thinking about it. The BBC and Amstrad CPC models were also close rivals, but nothing could divide the 'spice' between Sinclair and Commodore.

Over the earlier part of the 1980's Clive Sinclair oversaw licensing deals allowing other companies to clone the machine. Uncle Clive was eventuallyawarded a knighthood for his 'services to British industry' - and rightly so.

The ZX Spectrum, in all of its incarnations was a great machine. The way it was pushed way beyond it's limitations by clever developers is testament to the machines popularity and it's versatility. The fact that many classic arcade games were converted (and converted well) marks the Spectrum as an all time classic computer.

Remove your hat, bow, then raise a glass of champers and toast the Speccy. A fine retro computer.

To see further information about games, developers and software houses for this machine, go to ZX Spectrum Games

For more general Speccy info and vids go to Sinclair ZX Spectrum

We recommend trying to pick up one of these machines.
Look at computers for sale online or even locally.

If you don't want to get hold of the real hardware then try and download an emulator and
download those classic games. Alternatively you could try and play them online.

COMPUTER NAME: ZX Spectrum
MANUFACTURER: Sinclair
MACHINE TYPE: Home 8-bit Computer (classic games machine)
COUNTRY OF ORIGIN: United Kingdom
RELEASE YEAR: April 1982
END OF PRODUCTION: Standard 48K - 1984. Spectrum 128 - 1986
BUILT IN LANGUAGE(S): Sinclair Basic
KEYBOARD: QWERTY rubber keyboard (40 keys) with up to rather crazy 6 functions by keys
CPU: Zilog Z80 A
SPEED: 3.5 MHz
RAM: 16KB or 48KB (42KB available for programming)
ROM: 16k (Basic & OS)
TEXT MODES: 32 x 24
GRAPHIC MODES: 256 x 192
COLORS: 8 with 2 tones each (normal and bright except for Black which only had one tone)
SOUND: Basic beeper capable of 1 voice over 10 octaves
SIZE / WEIGHT: 16K - 48K - A nice and compact 23 x 14,4 x 3 cm / 550g
I/O PORTS: Expansion port, tape-recorder (1200 bauds), RF video out
POWER SUPPLY: External PSU, 9v DC, 1.4A
PERIPHERALS: ZX printer, ZX microdrives, Joystick Interfaces
PRICE: 16K model retailed at £99 (UK 1984) 48K retailed at £125 (UK 1984)

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Retro Computers - Sinclair ZX81 - Retro Computer

ZX 81
Peolpe really warm up to Uncle Clive.

The Sinclair ZX81 was the follow up to the ZX80 and was released by Sinclair Research Ltd in 1981. Once again, the machine was named after it's year of release. Like it's predecessor, it became a popular machine in homes the length and breadth of the UK.

As with the ZX80 the processor was a NEC Zilog Z80-compatible, running at a clock rate of 3.25 MHz. The system ROM had grown to 8192 bytes in size and the built in BASIC now supported floating point arithmetic. It was an adaptation of the ZX80 ROM by Steve Vickers, who was one of the authors of Sinclair BASIC. The new ROM also worked in the ZX80 and Sinclair offered it as an upgrade for the older ZX80 for a time.

Like the ZX80, the ZX81 was quite a basic piece of kit. The base system had only 1KB of RAM on board. This RAM was used to hold the computer's system variables, the screen image, and any programs and data. The screen was text only, 32 characters wide by 24 high. Blocky graphics with a resolution of 64 by 48 pixels were possible (created in BASIC using the PLOT command), which made a selection among a set of 16 graphics characters.

The ZX81 used a resizable screen buffer meaning that it could be expanded or shrunk (depending on the amount of installed memory and the amount of free space at any given time). No colours were available and the machine once again had no sound generator. The 'keyboard' as such was not a proper keyboard, with Sinclair once again going with the membrane pad similar to the ZX80.

Once again, sticking to a tried and tested formula, the ZX81 was originally sold via mail order in kit form which requiried soldering (priced at an incredibly cheap £49.95) or assembled (a still more than reasonable £69.95). The USA was treated to the same deal, with a ready made ZX81 costing roughly $100.

A deal struck with high street retailer W.H.Smith saw the ZX81 and all accessories being sold on the high street. The ZX81 retailled at £69.99, ZX 16K RAM pack went for £49.99 and the ZX Printer was available for £49.99.

Apart from having more BASIC commands than it's predecessor, it also had two modes of operation. Fast mode (the same as a ZX80) and slooooow mode. Slow mode made it like all other computers as in it refreshed the display all of the time. No Boney M home discos here.

The ZX81 was a simple affair and contained only four main chips. The ROM, Z80A CPU, 1KB RAM and the Ferranti custom-made chip. The ready made machines were assembled by Timex Corporation.

A vast range of peripherals were developed for the machine such as: 3.5" floppy disk units proper keyboards high resolution graphic cards RS232 or Centronics interfacesRAM expansions, etc...

In fact, it was possible to make a pretty powerful computer by upgrading the ZX81

The range of expansion options was really quite marvellous! For instance, a company called Memotech created a whole range of modules which would 'chain link' together one after another. The hardware pieces used velcro pads to secure to each other as there were no mechanical locking on the edge connectors.

So, all in all you could have additional memory (up to 128KB!), high resolution graphics, disc controllers, joystick controllers, serial ports etc etc. Holy smoke, with all of this kit you'd be the talk of the town. If you lived in GeekTown anyway.

A Popular add-on naturally was a replacement keyboard. Proper mechanical keys could be stuck over the membrane keyboard. Others involved re-housing the ZX81 inside a new, larger case with a 'proper' keyboard on it.

The options were almost endless. Sadly the power supply wasn't particularly stable making glitches commonplace which could result in system resets, usually just as you were entering the last line of a 2000 line program which would make you shout out 'Oh Shoot!'. Why did you never bother saving to tape until the whole thing had been completed?

'Ram Pack Wobble' was another expansion 'feature'. If you were lucky enough to have the 16KB RAM pack attached, sometimes moving the machine would cause the RAM pack to wobble in it's edge connector and cause the ZX81 to re-set. Again, this could break your day. A bit of blu-tac to secure the pack and you'd be back in proper business though. Those were the days of user tinkering.

The ZX81 was sold in the USA by Sinclair Research (from its facility in Nashua, New Hampshire). Timex Sinclair (a joint venture with Timex - as if you couldn't guess), also produced an enhanced ZX81 for the US market as the Timex Sinclair 1000 (or TS1000). This shipped with twice as much RAM (2kB) and featured mimetic-polly-alloy. It also had detailled files. A further enhanced model (the TS1500) expanded the RAM to 16KB.

Like the ZX80, the ZX81 was also cloned around the world. Microdigital produced two ZX81 clones (the TK 82C and the TK 83), and a TS1500 clone (the TK 85). Prológica produced the NEZ-8000 and the enhanced CP-200 and CP-200S models. Other clone models cropped up in various countries around the globe.

Looks wise, the ZX81 was a sleek and stylish machine. Far cooler looking than it's predecessor, the black case and Sinclair logo coupled with the almost 'silvery' membrane keyboard was ahead of it's time.

The ZX81 built up a reasonable software library. Quite a few computer games were available to play, most of them featuring very basic monochrome graphics. There was even a version of chess squeezed into 1K! Even basic 3D games were released, such as 3D Monster Maze. Someone even ported Manic Miner to it! Developers managed to get alot out of one of these machines.

More games sells more machines, and the ZX81 went on to sell roughly 1.5 million units. Not bad eh?

Turn around, look over your shoulder and give the machine more than a passing glance. A fine retro computer.

We recommend trying to pick up one of these machines.
Look at computers for sale online or even locally.

If you don't want to get hold of the real hardware then try and download an emulator and
download those classic games. Alternatively you could try and play them online.

COMPUTER NAME: ZX81
MANUFACTURER: Sinclair
MACHINE TYPE: Home Computer
COUNTRY OF ORIGIN: United Kingdom
RELEASE YEAR: March of 1981
BUILT IN LANGUAGE(S): Sinclair Basic
KEYBOARD: Touch-sensitive keyboard, 40 keys
CPU: Zilog Z80A
SPEED: 3.5 MHz
RAM: 1KB (901 bytes available, up to 128KB with expansion)
ROM: 8KB
TEXT MODES: 32 x 24 (2 lines are reserved for system messages and commands)
GRAPHIC MODES: 64 x 44
COLORS: Black and white only
SOUND: Nada
SIZE / WEIGHT: 167 x 175 x 40 mm / 350
I/O PORTS: Z80 Bus, tape, video
POWER SUPPLY: 9V DC
PRICE: Kit £50 (UK June 1981). Ready made £70 (UK June 1981)

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Retro Computers - Sinclair ZX80 - Retro Computer

Sinclair ZX80

Getting a 'ZedEx' delivery

The Sinclair ZX80 was a home computer manufactured by Sinclair (formaly known as Science of Cambridge Ltd). The computer was released onto the UK market in 1980 - hence the name 'ZX80'.

The ZX80 was notable for being the first computer available in the United Kingdom for under a hundred pounds as it retailled at £79.95. For technophiles it was available in kit form where the buyer could assemble and solder it together - MacGyver still wasn't around to do this for you.

For mere mortals a ready built version (at a slightly higher cost of £99.95) was available for purchase. The ZX80 was a very popular machine straight away, and for some time there was a waiting list of several months of buyers for the machine.

The machine was designed by Jim Westwood and was based around a Z80 CPU with a pretty impressive clock speed of 3.25 MHz. It was equipped with 1KB of static RAM and 4KB of read only memory which held the Sinclair BASIC programming language, the editor and the operating system.

BASIC commands were not entered by typing them out (as Sinclair machine users would come to know over the next few years) but were instead selected somewhat similarly to on a scientific calculator. Each key had a few different functions selected by both context and modes as well as by use of the shift key.

Display was over an RF connection (connected to a household television), and program storage was possible using a generic cassette recorder. The video display generator of the ZX80 used minimal hardware plus a combination of software to generate a video signal. This was an idea that was popularised by Don Lancaster in his 1978 book The TV Cheap Video Cookbook and his 'TV Typewriter'.

As a result of this approach the ZX80 could only generate a picture when it was idle, yes only when it was sitting doing nothing - as in waiting for a key to be pressed. When running a BASIC program, or even when simply pressing any key on the keyboard, the display would black out momentarily while the processor was busy.

This made moving graphics difficult since the program had to introduce a pause for input to display the next change in graphical output. I did make creating your own indoor monochrome disco easy though by repeatedly hitting the space button whilst listening to Bony M.

A year later as the ZX81 was released, the 8KB ROM was also usable with the ZX80 which allowed those MacGyver types to upgrade their machine to 'almost' be a ZX81. It came supplied with a thin keyboard overlay and a ZX81 manual.

To Upgrade:

• Take off the top cover of the ZX80
• Pry the old ROM from its socket and carefully insert the new ROM
• Add the keyboard overlay
• Spin round three times at precicesly 15:03 GMT and pray to Lord Clive with the 'I love Sinclair mantra'

The upgrade would now be complete. This was quite a cool feature - showing intercompatibily between machine models.

It was also possible to reverse this process to remove the upgrade. Sinclair also produced RAM expansion packs for the ZX80. The original ZX80 RAM Pack held either 1BK, 2KB or 3KB of static RAM. Later on a model that held 16KB of RAM was released which used dynamic RAM chips (yes DRAM!)

The ZX80 was never a technical marvel. It had no sound whatsoever and no colours to speak of (monochrome display only). It was also never a cool looker - the tiny white plastic case with the one piece blue membrane keyboard on the front always looked ordinary.

On top of this it was not the most durable of micros and was also prone to bouts of overheating. BUT - it did bring computing into the homes of the UK at a reasonable price, and made computing available to those that were not techno-geeks or hobbysists.

It also provided the platform for Sinclair, who would go on to release more succesful machines over the next few years. Sales of the ZX80 reached somewhere in the region of 50,000 which was an unheard of number for the day. This contributed significantly to the UK leading the world in home computer ownership through the 1980s. Due to it's success the machine was also cloned quite alot, machines such as the MicroAce and the TK82 being two.

Owing to the unsophisticated design and the tendency for the units to overheat, surviving machines in good condition are sparse. If you want one be prepared to pay a few quid.

Give this machine a nod, it deserves it for what it did for home computing - a fine retro computer.

We recommend trying to pick up one of these machines.
Look at computers for sale online or even locally.

If you don't want to get hold of the real hardware then try and download an emulator and
download those classic games. Alternatively you could try and play them online.

COMPUTER NAME: ZX 80
MANUFACTURER: Sinclair
MACHINE TYPE: Home 8-Bit Micro
COUNTRY OF ORIGIN: United Kingdom
RELEASE YEAR: February 1980
END OF PRODUCTION: 1981
BUILT IN LANGUAGE(S): Sinclair Basic
KEYBOARD: Membrane keyboard, 40 keys, 1 SHIFT key
CPU: NEC 780C-1 (Z80 compatible)
SPEED: 3.25 MHz
RAM: 1 KB, 901 bytes available (upgradable to a then massive 64 KB)
ROM: 4 KB. Can be expended to 8 KB making it 'almost' a ZX81
TEXT MODES: 32 characters x 22 lines
GRAPHIC MODES: 64 x 44 dots
COLORS: Monochrome only
SOUND: Zilch
SIZE / WEIGHT: 21,9 (W) x 17,5 (D) x 4 (H) cm / 375 gr
I/O PORTS: Z80 Bus, tape, TV/RF video
POWER SUPPLY: 9v DC external PSU
PERIPHERALS: 16 KB RAM extension
PRICE: Kit model: £79.95 (UK, 1980) Assembled model: £99.95 (UK, 1980)

Retro Computers and classic games

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