They didn't even use an ADC. They used 555 timers to produce a pulse. They measured the length of the pulse to determine the potentiometer position. Since there are 4 analog inputs, they typically used the 558 timer which is the quad version of the 555.

Wow, 30 years and I'm just learning this now. Thank you

More info: https://en.wikipedia.org/wiki/Game_port

The 15-pin D-sub connector itself was apparently a combination of analog and digital. It had to be, since MIDI is digital (it's right there in the name: Musical Instrument Digital Interface). TIL it wasn't all digital.

huh, i thought it was just because "owning a sound card" and "likely to play games" was the biggest overlap of the Venn circles.

Except that wasn’t a serial port, it was midi, and the reason it was on the sound card was because the input was analog.

Considering MIDI stands for Musical Instrument Digital Interface, I have no idea what you're trying to say.

I thought sometimes they called them game ports (for the joystick.)

I reasoned if you are installing a sound card, you are probably doing some gaming, so it made sense to sort of bundle those together.

All the naysayers never used a Gateway AnyKey keyboard... their loss.

They all got bought by acer and turned into the shittiest brand-name PCs on the planet.

My 286 had PS/2 ports instead of the obsolete DIN keyboard/serial mouse.

smug_look_of_superiority.jpg