this post was submitted on 12 Aug 2025
39 points (91.5% liked)
Programmer Humor
26673 readers
1655 users here now
Welcome to Programmer Humor!
This is a place where you can post jokes, memes, humor, etc. related to programming!
For sharing awful code theres also Programming Horror.
Rules
- Keep content in english
- No advertisements
- Posts must be related to programming or programmer topics
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Don't forget the serial input for gamepads and joysticks in the dedicated sound board for some reason
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.
huh, i thought it was just because "owning a sound card" and "likely to play games" was the biggest overlap of the Venn circles.
Wow, 30 years later 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.
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.
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.
And because the PC only have 1 serial port, you disconnect the printer and use a parallel to serial adapter.
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.
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.
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.