Atom

Released in 1980 by Acorn Computers Ltd., the Acorn Atom was a low-cost home computer kit (or assembled unit) designed to appeal to hobbyists and early adopters. Based on the MOS Technology 6502 CPU, it came with 2KB to 12KB of RAM, expandable up to 32KB. It featured an integrated keyboard, BASIC interpreter, and TV output. Though modest compared to later Acorn machines, the Atom’s design and success paved the way for the legendary BBC Micro. It was particularly strong in educational and scientific circles, offering surprisingly powerful integer and floating-point BASIC capabilities for its price.

Notable Features

• Early use of 6502 CPU, the same chip as the Apple II and Commodore PET
• Flexible expansion options for RAM, graphics, and storage
• Fast, integer-friendly BASIC with optional floating-point extensions
• Modest graphics but capable for technical and scientific applications
• Sold as either a self-assembly kit or fully built
• Led directly to the commissioning of the Proton project (which became the BBC Micro)

Historical Significance

• Critical stepping stone from hobbyist computing to mass education computing in the UK
• Formed the technological foundation for Acorn’s later domination of the British educational market
• Helped secure Acorn's BBC Micro contract by demonstrating technical competence
• Cult following among vintage computer collectors, particularly in the UK

Collector's Notes

• Rarity: Moderate – fewer built units survive compared to Sinclair machines
• Desirability: High among Acorn, BBC Micro, and 6502 enthusiasts
• Common Issues:
  • Video output drift or instability
  • Faulty RAM or ROM chips (especially on expanded systems)
  • Keyboard key bounce or dead keys (mechanical wear)

Specifications

Technical Information
Name	Atom
Manufacturer	Acorn Computers
Launched	Friday, February 1, 1980
Discontinued	2/1/1982
Country	United Kingdom
CPU	6502
Power	Internal linear PSU (via transformer plug)
Expansion	Edge connector for RAM, floppy disk interface, additional ROMs
Storage	Cassette tape (audio port for data saving/loading)
Keyboard	62-key QWERTY keyboard (mechanical keys)
Sound	Single channel beeper
Graphics	Text modes (32×16 or 64×16), limited graphics modes
Display	TV output – up to 256×192 pixels (with expansion)
ROM	8 KB (BASIC interpreter, OS routines)
RAM	2 KB standard (expandable to 12 KB or 32 KB with upgrades)