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/* CPC664 */
==Hardware description==
All CPC models were based on a [[Zilog ]] [[Z80 ]] processor clocked at 4 MHz. Because a common pool of RAM is shared with the video circuits, the Z80 may only make a memory access once every four cycles, which has the effect of rounding all instruction cycle lengths up to the next multiple of four. For details, see [https://web.archive.org/web/20170324233713/http://www.grimware.org/doku.php/documentations/devices/z80 a nearly complete list of instructions with timings (number of cycles) for each.]
The system came with 64 KB or 128 KB of RAM depending on the model (capable of being expanded to 576kmore). The machines also featured a standard 9-pin Atari-style joystick socket which was able to take two joysticks via a splitter.
The machines' dimensions are:
Disks were shipped in a paper sleeve or a hard plastic case resembling a compact disc "jewel" case. The casing is thicker and more rigid than that of 3.5" diskettes and the sliding metal cover to protect the media surface is internal to the casing and latched, unlike the simple external sliding cover of Sony's version (some reviews at the time reported driving over them with no problems). Because of this they were significantly more expensive than both the 5.25" and 3.5" alternatives. This, combined with their low nominal capacities and their essentially proprietary nature, lead to the format being discontinued when the CPC itself was discontinued.
Apart from Amstrad's other 3" machinemachines, the PCW, and the ZX Spectrum +3 (produced by Amstrad after their acquisition of the Spectrum from Sinclair), the only other computer systems to use them were the Sega SF-7000 and mostly obscure and exotic CP/M systems such as the Tatung Einstein and Osborne machines. It should be noted that some of these machines used drives with different pinouts and care should be taken when replacing drives.
The data formatting of 3" disks was very similar to that of 5¼" disks, and the Amstrad CPC machines were able to use 5¼" drives through their "external drive" port - either one specially designed for use by the CPC or an adapted IBM-PC drive.
=== CPC472 ===
The CPC 472 was a spanish version of the CPC 464 with additional (nonfunctional) 8 KB RAM. The reason for this was that Amstrad wanted to circumvent a Spanish law that levied an extra tax for machines with 64KB or less of memory; thus, they upped the spec to 72KB by including an additional 8KB though this extra memory was not functional.
* Amstrad CPC [[472]]<gallery>Image:CPC_472_es.jpg|The CPC472</gallery>
=== CPC664 ===
Image:CPC664_PCB_Top.jpg|CPC 664 Motherboard Top
Image:CPC664_PCB_Bottom.jpg|CPC 664 Motherboard Bottom
Image:Amstrad_cpc_664_plate.png|Amstrad CPC 664 Floppy Disc Drive Plate. PNG format.
Image:Amstrad_cpc_664_plate.svg|Amstrad CPC 664 Floppy Disc Drive Plate. SVG format.
File:Amstrad_cpc_664_plate.pdf|Amstrad CPC 664 Floppy Disc Drive Plate. PDF format.
</gallery>
