This blog documents my journey in constructing an 8-bit relay computer, from scratch, made from tons of solder, wires, lights, relays, sweat, tears, swearing and money.

The design of the computer is based on the one constructed by Dr. Harry Porter at Portland State University (reproduced on this blog with kind permission) but the construction method is my own and so this blog captures the thoughts, experiences and pitfalls that I encounter along the way.

For more information about the ‘whys and wherefores’ of building a computer of this type these posts are a good starting place:

  • It begins … the first post
  • Why? … musings on why I’m doing all this
  • The three Rs … further musings on where to start the journey

An overview of the architecture used in this relay computer can be found in the following posts:

The following posts go in to more detail … starting with the basics and building up from there:

An insight into the choice of relays to be used can be found here:

Finally, an initial instruction set can be found here:

If you like your information delivered in a more visual way here’s the most recent collection of ‘update’ videos from Jan 2020 which cover off many of the items above: