Acorn Atom Technical Details and Trivia

Technical Detail


  • Tape interface which uses the CUTS (Computer Users Tape Standard) interface running at 300 baud - 7-pin round DIN
  • Centronic parallel printer port - 26-pin IDC type male
  • Acorn Bus socket - providing access to entire 6502 CPU bus - 64-pin IDC-type male
  • UHF TV output jack
  • 8V DC unregulated 1.5A Power socket (Acorn-supplied PSU converts this 8V DC into 5V regulated DC inside the Atom) - 7-pin round DIN


Technical facts:

  • The original supplied Atom power supply is an 8V unit capable of 1.5A. This was insufficient to power an expanded Atom with all its RAM banks populated. 3A provides enough current.
  • A PAL Encoder unit could be installed inside the Atom to display colour images on a television. The expanded Atom's standard UHF output was monochrome.
  • The Atom's video uses a Motorola 6847 VDG (Video Display Generator) chip which provides 8 different display modes with graphics resolution up to 256x192. The same chip was used in the Tandy TRS-80 (CoCo) Models 1 and 2, Dragon 32 and 64, GEM 1000, NEC PC-6001, and the Laser 100/200/300 series.


  • Acorn's network, Econet, was first designed for use with the Atom.
  • The Atom manual was called "Atomic Theory and Practice".