12-Bit Relay Computer Design and Construction (2015)
Undergraduates: Katherine Frame, Alex Blate Andrew Vitkus, Daniel Chiquito, Neal Siekierski
Faculty Advisor: Henry Fuchs
Department: Computer Science
The goal of this project is to develop a functioning 12-bit computer made from dual pole - dual throw relays that can be displayed in the computer science building at UNC for use as an educational tool for students and guests.
We designed this computer around the concept of approachability. Anyone with some knowledge of computer architecture should be able to understand exactly what is happening everywhere in the computer, but people with no experience whatsoever should also be able to operate the inputs and outputs just as effectively. With this in mind, we decided that a modular, wall-mounted display would provide the best readability, with LEDs acting as data indicators. Every component has LEDs indicating inputs, outputs, and data flow so that users can watch every part of the computer at work. Users will be able to provide input to a number of programs, like a calculator and a bubble-sort implementation, and will be able to regulate clock speed, including manual stepping.
The computer is constructed to perform all logical functions using relays. Since an eight-bit architecture would have limited functionality, and a sixteen-bit architecture would have been too large to display effectively, we designed a twelve-bit architecture as a happy medium. The instruction set was chosen to be simple in functionality, consisting of only 32 instructions, while still enabling the flexibility required to run our sample programs.