Welcome to DAVIAC

The purpose of the DAVIAC1 Relay Computer it simply to re-demonstrate the most basic principles of computing in a highly visual way in which every bit can be tracked continuously. To this end I have chosen large format relays with easily visible contacts inside clear transparent cases. The single pole SPDT (single pole double throw) examples have 12V coils and 240V, 10A contacts. These relatively large power relays provide not only the visual evidence of operation, but also a most satisfactory sound. I had a very clear idea of the sound I wanted, and am very happy with the result.

Architectural Overview (click image for PDF)

A block diagram of the architecture of the DAVIAC-1 along with the instruction set and machine code

Physical Build Overview

All the PCBs for the DAVIAC-1 populated with relays, LEDs and other miscellaneous parts mounted neatly on some particle hinged board mounted to the wall. Miscellaneous vintage test equipment and a laptop with a lot of stickers on it in the foreground.
Name4 Pole2 Pole1 Pole
Scratch RAM21986

Total: 416, High density RAM32 boards are 484 each