From CPCWiki - THE Amstrad CPC encyclopedia!
Revision as of 01:53, 29 September 2006 by (Talk) (Introduction)

Jump to: navigation, search


The Amstrad CPC (Colour Personal Computer) series was a series of 8-bit home computers that were manufactured by the British company Amstrad between 1984 and 1993 (?). The CPC, like most contemporary home micros, had an integrated computer-in-a-keyboard design. Also incorporated in the keyboard was the tape recorder or disk drive.

In general what Amstrad aimed for was to offer a completely integrated solution at a low price. Just as Amstrad's stereo towers before, A.M. Sugar wanted to provide a solution with as few separate components as possible, with as few cables as possible and at as low a price as possible - so as to make the product attractive to the layman who could theoretically buy it off the back of a track (TM of Amstrad's early practices (eh?)). As a result, he chose ready off-the-shelf components and used low-cost production methods in an effort to bring manufacturing costs down. He also included a monitor to connect the computer to - a move which, while raising the price, was designed to free the home TV from little brats hogging it for a dose of Ikari Warriors while Eastenders was on. This concept appealed to users and proved to be a success.

The combination of low cost, integrated design, good manufacturing quality and some impressive features like CP/M and an 80-column display mode (which was lacking in the competition) proved to be a success both with home users and small businesses, and Amstrad went on to sell millions of CPCs.

However, because of its use of the Z80, which was also used in the Sinclair models, many of the games found on the CPC were direct ports of the Spectrum versions. As a result, they failed to take advantage of the CPC's extra capabilities, leaving users and reviewers with a bad taste in their mouth, a situated that lasted for the entire life of the machines.

The CPC's operating system was called AMSDOS (Amstrad's Disk Operating System) and was included on a ROM chip of 48KB. Also in ROM there was the Locomotive BASIC interpreter which made the CPC very fast in BASIC operations, compared to other contemporary machines.

In all, there were three basic models, the CPC 464, 664 and 6128, plus two more advanced models, the CPC464+ and the 6128+. A final iteration was the GX4000 games machine based on the CPC+ computers.

See also: CPC Prototypes

The 464

Amstrad CPC 464 with colour monitor

First came the CPC464, the father of the CPC family, released during the summer of 1984 (with production ceasing in 1990). This model used an integrated tape recorder and used 64KB or RAM. It sold around 2 million units in Europe and, technologically-wise, was more impressive than the ZX Spectrum and on a similar level with the Commodore c64 (with the notable exception of the sound chip; while the c64 employed the splendid SID chip, Amstrad opted for a generic sound chip - AY-3-8912 - with unremarkable features). At its core was a Z80 clocked at 4MHz while the display was managed by the 6845 CRTC along with a gate-array chip.

The CPC464 sported a palette of 27 colours and three distinct resolutions: 160x200x16 colours (mode 0), 320x200x4 colours (mode 1) and 640x200x2 colours (mode 2, 80-column mode).

The 472

Spanish Amstrad CPC 472

The CPC 472 was a spanish version of the CPC 464 with additional 8 KB RAM.

The reason Amstrad released a special version for the spanish market was a law that said that every computer with up to 64kb should adhere to some rules - namely, have extra keys for the spanish language otherwise an extra tax would be levied. So Amstrad soldered in an extra 8kb which was not, however, usable by the machine since it was not connected to anything else. Later on Amstrad released a 472 with a proper spanish keyboard and the 8 extra kB as well.

After the rule changed there was also a CPC 472 with non-spanish keys available for a very short time. The CPC 472 with spanish or british keyboard is very very rare.

The 664

Amstrad CPC 664 with colour monitor in 80-column display mode

A few months later Amstrad took the initial design and, building upon the same idea, removed the tape recorder and replaced it with the interface and mechanism of the external Floppy Disk Drive it was selling up to then. The result: the CPC664. Sporting a less colourful and easier-to-type-on keyboard, the CPC664 appealed as a more serious machine and set off to become a success, especially due to its quite fast 3", 180KB/side drive.

The 6128

Amstrad CPC 6128 with colour monitor

Success never came, however, since a few months after its launch Amstrad presented the CPC6128 which was a 664 with redesigned keyboard (yet again) and double the amount of memory - a great 128KB. This effectively killed off the 664, to its users' frustration, since it offered more at the same price. The 6128 came bundled with CP/M 2.2, DR Logo and CP/M+ (with the GSX extension) and it was quite an appealing solution at a low price. Though the 128KB of memory could not be accessed all at once (due to Z80's limitation), the upper 64KB could still be used as a RAM disk and brought into view through memory banking. Even without this amount, however, Amstrad's efficient designed allowed for a TPA (Transient Program Area) of 42KB, more than enough to run all CP/M software.

The Plus series

Amstrad CPC6128+ with colour monitor

The last models in the Amstrad 8bits range were the Amstrad 464+ and Amstrad 6128+, launched together in 1990. It couln't be called "CPC" because Amstrad were sued by another firm still using it. Described as a solution of 'too little, too late', this was Amstrad's effort to prolong the life of its 8-bit computer series in the face of fierce competition from new 16-bit machines (notably, the Atari ST and the Commodore Amiga). The plus series were mostly (but not quite 100%) compatible with the original CPC computers, and incorporated a list of new features, like a cartridge port for instant program loading, DMA for the AY soundchip (managed with another Z80), hardware scrolling, programmable interruptions, 16 hardware zoomable sprites (not vectorized) with 15 other colours than the bitmap palette, and a palette of 4096 colours all in a new, sleek case which reminded the higher-end machines. While the "Amstrad Plus" computers were arguably one of the best 8-bit computers ever built for the mass market, they died a natural death as the 16-bit era had trully and well set in.

The GX4000

The Amstrad GX4000

By 1990 Amstrad had realised that the home market was heading towards the 16-bit machines, one one hand, and towards the new generation of game consoles like the Sega Master System or the Nintendo Entertainment System, on the other. Therefore, just as they created the 464+/6128+ by upgrading the old machines, to compete against the ST and the Amiga, they also created a stripped-down variant called the GX4000. The GX4000 was, in essence, a 464+ motherboard in a new case, with no keyboard and with most entension ports gone - save for the cartridge port and two joypads.

As was quite easy to predict, the GX4000 was a flop, and something of a 'way too little, quite a bit late' solution that could not penetrate the stranglehold that Sega and Nintendo had on the market at the time. As a result, the GX4000 was soon to be found selling at ridiculously low prices as dealers were trying to offload their stock. It was a shame, because if Amstrad had realised the market potential and produced this console a few years earlier, it could well have been a success. As it was, it had to suffer the same fate as the Commodore 64GS.


All in all, the CPC series met with great success. Although they would never achieve the status of the c64 or even the humble Spectrum series, the CPCs managed to sell very well and attain leader status in several countries. The CPCs were very popular in the UK, Spain, France, Greece, Germany and Australia, to name a few countries.

Besides a lot of Emulators several old and modern hardware Clones have been produced up to now.