I didn't mean MIDI literally, but the SNES and N64 have discrete soundchips that sound very much like primitive MIDI synthesizers. There's a ton of instrument definitions that get recycled over again in a variety of games. That's why many SNES and N64 games had orchestral sounding compositions, some of which were extremely good.
Primitive MIDI synthesizers? MIDI synthesizers weren't primitive. The first wave of them are capable of producing the chiptuney square/saw/whatever waves you want to hear. lol.
The Roland Juno-106, for example.
I assume these instrument profiles were probably defined by audio libraries included with the dev kits and likely stored somewhere in the game code. I don't pretend to know how they operate, but many of the instruments sound very similar to MIDI sound, ie select an instrument profile and play a note.
They're samples. So, they don't sound like "primitive MIDI synths" (I am not sure what this actually means). They sound like samples. It's a lot like the Amiga.
Stop using the term "MIDI sound". It's completely wrong.
As was already pointed out, MIDI is silent. It's digital data instructing the interface to do things. You can control lights with MIDI.
To further explain why this is wrong: all of the chiptunes I make are ultimately stored in MIDI format.
Insanity's CD soundtrack, is all MIDI driving analog synths. The lead noise is a Commodore 64 controlled via MIDI. So, your "chiptune" thing is being controlled via MIDI.... and then recorded to .WAV and played as a CD track...
SNES was just more MIDI sounding, less chiptuney, for lack of a better word.
There is a better word.
It's sample-sounding. You could use chippy samples for SNES, and some games do.
But, at the time, people were striving to make more "realistic" sounding music, like CD games had.
What you are trying to say is, they sound like that shit Windows GM library that MIDI files on Windows 95 used to play when you'd go to someone's GeoCities page back in 1997.
That's not "MIDI sound".
That's a crap instrument library.