All the video games in the 80s used custom synth chips that were part of the video game circuit board. They allowed a programmer the ability to program sounds ( bleeps boops etc ) for video games. Some games machine/computers/consoles had better sound than other dependant completely on the audio chips on the circuit board.

I worked for many years on the Commodore 64 that had a SID chip for audio that was very cool to program and could make some good analog emulations despite it being a digital chip.

You can still run many old games on your PC using Mame and other emulators, so you can always sample old video/computer games sounds to use in your own music.