(^Commodore Colt)

From 1984-1991, Commodore manufactured and sold their own PC computers, alongside their own C64/128 and Amiga computers.

Boards of Canada played on a 1959 PDP-1 Computer

Audio is produced on the PDP-1 with a clever hack done by Peter Samson as a student at MIT in the early 1960s. The PDP-1 has six "program flags", which are 6 flip-flops wired to six light bulbs on the control panel. A CPU instruction provides the ability to turn these light bulbs on or off via software. While these bulbs were originally intended to provide program status information to the computer operator, Peter repurposed four of these light bulbs into four square wave generators (or four 1-bit DACs, put another way), by turning the bulbs on and off at audio frequencies. Four wires are attached to the signal lines for these light bulbs. Resistors are used to downmix these four signals into stereo audio channels and provide impedance matching into a standard stereo amplifier, and combined with capacitors to create low pass filters to cut out the buzz of the computer noise and soften the square waves. The four light bulbs act as individual music voices. Each voice is transcribed separately using a custom DSL defined for the 1962 Harmony Compiler, and then merged into a single file which is then compiled by the original Harmony Compiler running on a PDP-1 emulator. The resulting paper tape file is then punched to physical paper tape using a tape punch, and then loaded into the real PDP-1 for music playback.

Samson also contributed to Spacewar!, one of the earliest videogames.