Amstrad CPC 664

Introduced in the United Kingdom in May 1985, the Amstrad CPC 664 replaced the CPC 464’s cassette recorder with a built-in 3-inch floppy disk drive. It retained the 4 MHz Zilog Z80A processor, 64KB of RAM, colour graphics and AY-3-8912 sound of the original CPC while adding a redesigned keyboard and faster disk-based storage.

The CPC 664 shipped with Locomotive BASIC 1.1, AMSDOS and CP/M 2.2. It was sold as a complete system with either a green-screen or colour monitor, but remained on the market for only about six months before the 128KB CPC 6128 took its place.

Notable Features

• Integrated 3-inch single-sided floppy disk drive storing about 180KB per side
• Locomotive BASIC 1.1 and AMSDOS in ROM
• Supplied with CP/M 2.2 and Digital Research LOGO
• Redesigned keyboard with cursor keys above the numeric keypad
• Three display modes and the CPC family’s 27-colour palette
• External cassette interface retained for compatibility with CPC 464 software

Historical Significance

• Amstrad’s first CPC with an integrated disk drive
• Bridged the cassette-based CPC 464 and the 128KB CPC 6128
• Its very short production life makes it the least common of the original three British CPC models
• Maintained strong software compatibility with the CPC 464 while encouraging disk-based software

Collectors Notes

• The original drive belt commonly deteriorates and is a routine replacement
• Three-inch disks are less common than 3.5-inch media and should be handled carefully
• The computer requires a compatible Amstrad monitor or a suitable power and video adapter
• Check the drive, membrane keyboard, edge connectors and monitor power leads
• Complete systems with the matching CTM644 or GT65 monitor are especially desirable

Specifications

Technical Information
Name	Amstrad CPC 664
Manufacturer	Amstrad
Launched	Wednesday, May 1, 1985
Discontinued	Late 1985
Launch Price	£339 with GT65 green-screen monitor; £449 with CTM644 colour monitor
Country	United Kingdom
CPU	Zilog Z80A
Units Sold
Power	5V and 12V DC supplied by the dedicated Amstrad monitor
Expansion	Expansion bus, second-drive connector, Centronics-compatible printer port, joystick port, RGB/video and stereo audio
Storage	Built-in 3-inch single-sided floppy drive, about 180KB per side; external cassette port
Keyboard	Full-size QWERTY keyboard with numeric keypad and separate cursor keys
Sound	General Instrument AY-3-8912, 3 voices over 7 octaves
ROM	48KB: 32KB operating system and BASIC, plus 16KB AMSDOS
RAM	64KB
Graphics	Motorola 6845-compatible CRTC; 27-colour palette
Display	Mode 0: 160 × 200, 16 colours; Mode 1: 320 × 200, 4 colours; Mode 2: 640 × 200, 2 colours
CPU Speed	4 MHz