ACT 800

The ACT 800 was Applied Computer Techniques’ first microcomputer, a British-market version of the American CompuThink MiniMax. It combined a 6502 processor with an integrated monitor, keyboard and disk storage for business and technical work.

Its extended processor instructions and FIFTH language environment distinguished it from ordinary 6502 systems. ACT’s experience marketing the machine helped prepare the Birmingham company for its later success with the Sirius and Apricot ranges.

Notable Features

• Integrated business-computer format with monitor, keyboard and disk storage.
• A modified 6502 environment supported 64 user-definable instructions.
• High-resolution graphics and a full-screen editor were unusual strengths for a 1980 microcomputer.

Historical Significance

• The first microcomputer sold under the ACT name.
• A rebadged CompuThink MiniMax rather than an ACT-designed machine, but an important first step toward Apricot.

Collector’s Notes

• Surviving machines and documentation are exceptionally scarce.
• ACT 800 and CompuThink MiniMax variants may differ in storage configuration and badging.

Specifications

Technical Information
Name	ACT 800
Manufacturer	Applied Computer Techniques Ltd
Launched	Tuesday, January 1, 1980
Country	United Kingdom
CPU	MOS Technology 6502 at 2 MHz
Units Sold
Operating System	CompuThink BASIC, monitor and FIFTH development environment
I/O	Serial and parallel interfaces; expansion depended on configuration
Keyboard	Integrated full-travel keyboard
Storage	Integrated floppy-disk storage
Sound	Internal beeper
Graphics	Up to 512 x 240 monochrome graphics
Display	Integrated 12-inch monochrome CRT; 64 x 30 text
ROM	16KB
RAM	48KB user RAM; approximately 108KB system memory
CPU Speed	2 MHz