Harry Porter's Relay Computer
More Info

Last updated: 17 November 2009 (Circuit diagrams added)


For an in-depth video presentation describing the design of machine, click here (to intro page).

For a movie (same as the YouTube movie)... click here (3 MBytes, 2:00 minutes, includes discussion)

For another movie, click here (Silent, 14 seconds, 2 MBytes)

For the sound of relays, click here (30 seconds, MP3, 0.5 Mbytes)


Short Paper
Here is a short discussion, including an overview, the instruction set, and misc. commentary about the construction (10 pages).
Click here for html
Click here for .txt file

Long Paper
Here is a paper discussing the circuits and the design of the machine in much greater depth (92 pages).
Click here for PDF
Click here for html

PowerPoint Slides
Here are some slides from a presentation on the computer.
Click here for PDF
Click here for .ppt

Sample Programs

Simple Subtract Program
16-bit Subtraction Program
Multiply Program
Simplified Multiply Program

Circuit Diagrams

Click here for more

Related Work by Other People

For a simulator written by Ward Cunningham, click here (For Ward's code, written in PERL, click here)

For a simulation by Mike Birken, click here.
(Mike has written a relay circuit simulator in Java, called TOFU. In addition to typing out all the individual relay connections, he has written and executed a program to draw a fractal known as the Dragon Curve. He also has extensive documentation.)

About the Author

Harry H. Porter III, Ph.D.
Computer Science Department
Portland State University

Relay Computer, main page: www.cs.pdx.edu/~harry/Relay
Harry's Website: www.cs.pdx.edu/~harry
Short Bio: click here
Email: harry@cs.pdx.edu