Effects
10xx: Set waveformxxis a bitmask representing a pattern of on-off pulses- This has nothing to do with wavetable assets, which can’t be used by the PET
Computer Chips
Commodore PET
A 1977 computer with an 8-bit shift register sound chip
A computer from 1977 which was leader in US schools back then. Subsequently the Apple II took its throne.
Maybe no better than a computer terminal, but somebody discovered a way to update the screen at turbo rate - and eventually its sound “chip” (it was nothing more than an 8-bit shift register) was abused as well.
Some of these didn’t even have sound output, leaving the user to solder in a speaker on their own.