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

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

Specifications

• CPU: MOS Technology 6502
• Speed: 1 MHz
• RAM: 2 kB, expandable to 12 kB
• ROM: 8 kB
• Sound: 1 channel, integral loudspeaker
• Size: 381 x 241 x 64 mm
• I/O Ports: Computer Users Tape Standard (CUTS) interface, TV connector, Centronics parallel printer
• Storage: Kansas City standard audio cassette interface
• Power: 8 volts DC, providing 5 volts stabilised

External links

• http://www.xs4all.nl/~fjkraan/comp/atom/index.html
• http://www.howell1964.freeserve.co.uk/Acorn/Atom/Atom.htm
• http://home.wanadoo.nl/hhaydn/index-uk.html