PDP-8/L Minicomputer Restoration and Programming

Abstract

In this project we are restoring a Digital Equipment Corporation (DEC) PDP-8/L minicomputer with its associated teletype and coding several different interesting programs to run on it. So far, we have successfully repaired the power supply, replaced a defunct cooling fan, fixed the front panel, tested several components of the core memory, and created a library of basic programs on an emulator in PDP-8 assembly language (PAL). We are currently awaiting replacement incandescent lamps for a few broken and missing display lights. There are two known remaining problems we have yet to remedy, both involving the core memory. Diagnosing and repairing these issues is our current priority, as fixing them will allow us to begin running programs on the physical machine. We have future plans to design a current loop to RS-232 converter allowing modern laptops to interface directly with our PDP-8, as well as code a host of more advanced programs for the machine, including a LISP interpreter.