> early IBM computers shipped with pretty simple, magnetically driven dynamic speakers

Yes the PC & donkey.bas were monophonic design, but the PCjr shipped with 3-channel polyphonic sound plus a noise generator. It might have been capable of doing the sounds in this port of donkey that took “some liberties”. ;)

I remember some sound demos on the PC that emulated polyphonic sound by fast/audible switching between notes in a chord. Hey it seemed cool at the time. :P I just looked and couldn’t find any quickly enough but bumped into examples of even better true polyphony on the PC achieved by assembly hacking.