Computer History
Tracing the History of the Computer - Acorn Atom

The Acorn Atom was a home computer made by Acorn Computers Ltd between 1981 and 1983, when it was replaced by the BBC Micro (which was originally called the Proton) and later the Acorn Electron.

Acorn Atom, 1981 - 1983

The Atom was a progression of the MOS Technology 6502 based machines that the company had been making from 1979. The Atom was a cut-down Acorn System 3 without a disk drive but with an integral keyboard and cassette tape interface, sold in either kit or complete form. It was priced at around £175.

It had a MC6847 VDU video chip, allowing for text or two-colour graphics modes. It could be connected to a TV or modified to output to a video monitor. Basic video memory was 1 kbyte but could be expanded to 6 kbyte. A PAL colour card was also available.

It had built-in BASIC (Atom BASIC), although in an idiosyncratic version, which included poke and peek operators for bytes and quadruple bytes. It also included an assembler allowing you to produce machine code as output of a program.

The Acorn LAN, Econet, was first configured on the Atom.

The computer case was designed by industrial designer Allen Boothroyd of Cambridge Product Design Ltd.