This is my halfhearted attempt at creating the portal 2 ending on ancient computers.
Computers in this video are:
IBM PC-XT - 1983
Compaq Portable - 1984
Compaq SLT-386 - 1989
Compaq LTE Elite 4/75CX - 1994
The program used to create this was Microsoft qbasic for ms-dos. The computers were manually synced.
More information:
PC compatible computers of this era did not normally include sound hardware, and the only way to produce sound was through the PC speaker. The PC speaker is normally only capable of playing a single tone at a time, so in order to produce harmony I used four computers, one for each voice. Programming the song was done by manually typing in the sequence of tones in each computer, then starting the four different programs at the same time. The beeping at the beginning is to help me sequence the start of the programs with each other.