Amstrad CPC

History

This project began in 1983, Amstrad, British company producing material HI-FI directed by Alan Michael Sugar (often shortened in " AMS"), is in the search of a new crenel. AMS sees a vacancy in the market of the microprocessing of the time: up to that point, indeed, she addressed herself before very to “hobbyists”, impassioned or likely to become it (from where not very expensive computers, but in kit or with of connections being realized as well as they quickly became about it nightmares of plumbers, or apparatuses with the point of the technique, but very expensive and still with half experimental). Alan Sugar chooses to be addressed to resolutely family, inexperienced customers and without great ways: it thus decides to sell a computer whose installation is simplest possible, and who directly usable even by a layman as of the powering (from where is the monitor included and the remarkably reduced number of cables for the time), the whole for the same price as a Commodore 64. Moreover, to remain in this logic of family customers, Amstrad will organize its sales outlets only on the basis of large distribution.

In 1984 leaves the Amstrad CPC 464, including/understanding random access memory, sold with a monochromic screen (green) or a color screen and, unusual thing at the time, a cassette player integrated. Amstrad CPC 464 is as of its exit an immense success, especially in France, being sold with more than 2 million specimens.

In 1985 leave successively the Amstrad CPC 664 where the cassette player is replaced by a disk drive, then the Amstrad CPC 6128, where the random access memory is carried to.

In 1990, seeing its sales CPC to decline, Amstrad tried to take again the market with a more advanced version of the CPC, the CPC+: 4096 Color S, sprite S managed by the material, channels DMA for the sound, port cartouche, new design. These machines however did not have any chance vis-a-vis the Amiga and Atari of the time. Range CPC+ disappeared quickly from the rays.

Range

Originals

The first figure in the name of the CPC indicates the type of the storage system: 4 for a storage on cassettes, 6 for a storage on diskettes 3". The following figures indicate the quantity of RAM.

Amstrad CPC 464 (Arnold 1): Cassette player, RAM
Amstrad CPC 472 (Arnold 1): Cassette player, RAM (Model specific to Spain)
Amstrad CPC 664 (Arnold 2): Disk drive, RAM
Amstrad CPC 6128 (Arnold 3): Disk drive, RAM (of which of paginated Memory)
Amstrad CPC 464+ (Arnold 5): Cassette player and port cartouche, RAM
Amstrad CPC 6128+ (Arnold 6): Disk drive and port cartouche, RAM
GX-4000: a game console based on the hardware of the CPC+

These machines all were equipped with a microprocessor Zilog Z80 with 4MHz (except the CPC+ which had Z80 with 4,4444 MHz, but which did not bring any profit speed, this increase in frequency was useful for the additional possibilities established in the CPC+).

(One can read with many places which this speed was of 3,3 MHz, this is due to the architecture of the CPC, the CRTC using the same RAM that Z80, this one was to wait for the periods of reading of the CRTC, it is thus a speed estimated by holding account of this waiting.)

Arnold 4

Case of Arnold 4. There also was a cheap CPC6128 which functioned in the same way that the original CPC but with a printed circuit and a ASIC which reduced in a considerable way the size of the mother chart and the number of chips. If you open a CPC 6128 and that the chart occupies all space then you have one of the originals. So when you open it, the chart occupies approximately only two thirds of space available with much of vacuum around, you have Arnold 4.

CPC472

The CPC472 is a rather special model only left to Spain.

It had been created by the Spanish distributer without informing the head office of it to circumvent a Spanish law of the time which required that all the home computers with less of RAM have the characters specific to the Spanish language.

The distributer received the CPC464, modified them (a small assembly which was put at the place of one of the ROMANIANS to add a chip of RAM) and modified the inscription in CPC472.

Some time after this law was extended to all the family models.

CRTC

Independently of the models of the range, Amstrad used CRTC ( Cathodic Ray Tube To control ), coming from various manufacturers. These CRTC presented many differences, even if their principal characteristics were identical. Thus a Démo written for the CRTC 1 can not be posted correctly (or at all) on a CRTC 0. Five types of CRTC can to date be detectable logiciellement:

CRTC 0: chipset HD6845 (Hitachi)
CRTC 1: chipset UM 6845R (UMC),
CRTC 2: chipset UM6845S (UMC) or MC6845 (Motorola),
CRTC 3: Asic of the CPC+,
CRTC 4: Asic of Arnold 4

To note that the numbers of CRTC were allotted by impassioned which tried to exploit the machine with its maximum. That explains why the numbers do not respect the chronological order: The CRTC 4 (Asic of CPC old generation) is older than the CRTC 3 (CPC +), the 4 having been “discovered” only after the exit of the CPC+.

Peripherals

Several peripherals were sold with the CPC or separately, like a printer, a joystick, a mouse (of not very ergonomic use), an external disk drive, or a tuner TV (which made it possible many teenagers in the Eighties to have for the first time a television set in their room),…

It was also possible to carry to the memory of the CPC 464 and 664 with an extension memory connecting on the port of extension of the CPC. The interface of the external disk drive was then inserted in the port of the extension memory.

See too

List of plays Amstrad CPC
Amstrad CPC 464
Amstrad CPC 6128
CRTC

External bonds

cpc-forever.com The CPC-Community! (German, english and french Portal).
The CPC Wiki the encyclopedia dedicated to the CPC.
CPC Zone - important Database of titles CPC.
Amstrad Today Site general practitioner on the CPC.
Phenixinformatique.com - Gate French-speaking.
CPC Rulez - many articles on Amstrad CPC.
CPC Scene Scene Demonstration CPC.
Impact/CPC6128 Europe - Site and forum devoted to the CPC and CPC+.
CPC-Hardware - Assemblies and Do-it-yourselfings Hardware for Amstrad CPC.
The Amstrad cpc manor - the nostalgia of the plays cpc.

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