Vintage Computing Tiny ACE

The Tiny ACE – coming soon!

The Pilot ACE computer was built at the National Physical Laboratory in England from 1946 to 1951, based on a design by Alan Turing. While intended merely as a testbed for a full-scale “Automatic Computing Engine”, it was one of the fastest computers of its time, running at a bit clock rate of 1 MHz.

Turing came up with a minimalist computer design, a bit-serial architecture which could be implemented with less than 800 vacuum tubes. The computer was designed around ultrasonic delay line memory: Program instructions and data were stored as trains of ultrasound pulses which travelled through mercury-filled tubes. It essentially knew only one operation – a data transfer from a source to a destination address. Arithmetic and logic operations, as well as branching, were implemented via dedicated source and destination addresses which performed the required functions.

I built a scaled-down functional model of the Pilot ACE. The “Tiny ACE” uses simple integrated logic circuits and real ultrasonic delay line memory. I am working on a project description and on cleaning up the project schematics and source files, to be shared here soon. In the meantime, a few teaser photos below…

The first public demonstration of the Pilot ACE in 1950. Left to right: Hollerith card punch/reader, operating console, tube rack with short memory tanks.

The first public demonstration of the Pilot ACE in 1950. Left to right: Hollerith card punch/reader, operating console, tube rack with short memory tanks.

The Pilot ACE console in its final form, from 1951 onward. Image courtesy of The Board of Trustees of the Science Museum, used under license CC BY-NC-SA 4.0

The Pilot ACE console in its final form, from 1951 onward. Image courtesy of The Board of Trustees of the Science Museum, used under license CC BY-NC-SA 4.0

The Tiny ACE functional model: A single-board computer built from 74HC series logic. The three blue packages in the background are the ultrasonic memories, made from chroma delay lines from a PAL TV.

The Tiny ACE functional model: A single-board computer built from 74HC series logic. The three blue packages in the background are the ultrasonic memories, made from chroma delay lines from a PAL TV.

The Tiny ACE complete with its optical reader for printed paper cards, which replaces the punched card reader for long-term program storage.

The Tiny ACE complete with its optical reader for printed paper cards, which replaces the punched card reader for long-term program storage.