Amstrad CPC 664

Amstrad CPC 664 keyboard

Amstrad released the CPC 664 in june 1985 (knowing that the CPC 6128 would follow very soon). It is based upon the 464 hardware but with a built-in 3” disc drive interface instead of the tape deck. Besides, a revised version (40008) of the Gate Array appeared, the first Gate Array version (40007) used in the 464 was not very reliable. It was possible to purchase a CPC 664 with a green screen (GT65) or color screen (CTM644). The built-in disc drive interface is the same than the Amstrad DDI-1 add-on for the 464.

Like the 464, it has it's OS and BASIC interpreter built-in as ROMs, but the Amstrad firmware got updated to version 2 and the Locomotive BASIC to v1.1.

The project codename was IDIOT: Includes Disc Instead Of Tape (don't take that too seriously, I'm not sure at all about it but I find it very funny :)




This is what a CPC 664 displays on startup (with a color monitor/tv set). The firmware indicate (v2) and the Locomotive BASIC say 1.1

Amstrad CPC 664 bootscreen, Firmware v2 and BASIC 1.1. Schneider CPC 664 bootscreen, Firmware v2 adn BASIC 1.1.

External Links

Further informations about the CPC 664 can be found at these websites:




  • 50Hz (PAL) or 60Hz (NTSC) framerates.
  • 3 screen modes (official):
    • MODE 0 : 160×200 with 16 colors.
    • MODE 1 : 320×200 with 4 colors.
    • MODE 2 : 640×200 with 2 colors.
  • Up to 64Kb Video-RAM.


  • AY3-8912 Soundchip, 3 channels, 7 octaves.
  • Built-in internal speaker (mono) with volume control.
  • Stereo jack output.


  • 64Kb of RAM.
  • 48Kb of ROM:
    • 16Kb for the Amstrad Firmware v2.0
    • 16Kb for the Locomotive BASIC 1.1
    • 16Kb for the AmsDOS v0.5

Mass Storage


  • 74 keys with numeric pad.

Dimensions & Weight

  • Width: 580mm
  • Height: 70mm
  • Depth: 170mm
  • Weight: 2.4kg

Power Supply

  • Socket for 5V DC, 2A (motherboard)
  • Plug and lead to 12V DC, 0.4A (disc)


Keyboard layout

The CPC 664 only had an english keyboard layout (no french/spanish/etc localisations were made).


Amstrad CPC 664, standard keyboard layout.

Circuit Diagram

CPC 664

The Amstrad CPC 664 Circuit Diagram (from the CPC 664 Service Manual).

Closup views

Amstrad CPC 664 circuit diagram: Gate Array Video outputs

Amstrad CPC 464, 664 and 6128 circuit diagram: AY3-8912 Sound outputs

Disc Drive Interface

The Amstrad Disc Drive Interface


Amstrad CPC 664

documentations/hardware/amstrad.cpc664.txt · Last modified: 2009/10/12 00:27 by grim