Early PC only had 5 card slots, and the only jack on the motherboard was the keyboard. One slot is going to be used by a video card, one’s probably being used by a hard drive controller, one’s probably used by a parallel + serial card. Soundcards also included controller ports to try to save a slot.

[–] jaybone@lemmy.zip 1 points 10 months ago (1 children)

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.

[–] the_crotch@sh.itjust.works 1 points 10 months ago

Its on the sound card because it's a midi port. Its designed for connecting a keyboard (as in electronic piano). Most people used it for gamepads but that's not what it was there for.

[–] BigDanishGuy@sh.itjust.works 1 points 10 months ago (4 children)

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.

Your joystick was just two fancy potentiometers, and your soundcard decoded the voltage on the middle legs into a position.

Soundcards handled joysticks because they had the fastest ADCs.

[–] grue@lemmy.world 1 points 10 months ago

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.

[–] grozzle@lemmy.zip 1 points 10 months ago

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

[–] josefo@leminal.space 1 points 10 months ago* (last edited 10 months ago)

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

[–] cmnybo@discuss.tchncs.de 0 points 10 months ago (1 children)

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.

[–] BigDanishGuy@sh.itjust.works 1 points 10 months ago* (last edited 10 months ago)

And here I thought I had it all figured out. But it does make sense. Doing it with an analog signal introduces noise and measuring pulse widths is going to be simpler.

[–] bountygiver@lemmy.ml 1 points 10 months ago

And because the PC only have 1 serial port, you disconnect the printer and use a parallel to serial adapter.

[–] Evil_Shrubbery@lemmy.zip 0 points 10 months ago (1 children)

Yes, this is where my PC master gaming started.

[–] JoMiran@lemmy.ml 1 points 10 months ago