Hi,

From the category of weird (and possibly useless) hardware, I've designed an ISA card that can control the volume of the PC Speaker through software. I created it in 2021 and wrote the software at the same time, but I didn't have time to assemble the card or test the driver until this summer.

I programmed the driver in assembler and uploaded the source code on Github / PC Speaker Driver
For the entire reading, I have set up a new project page on my site at Microelectronics / PC Speaker Driver

I thought this project might be interesting for the retro-computer enthusiast community.
Yes, I know a sound card (even my DIY Audio Interface) can control the volume of the PC Speaker through software. But I like weird hardware. Unfortunately the volume control is not entirely linear, but it works good for my needs. I just wanted to be able to turn it down in some games.

Here are a couple of pictures. I'll try to make a video of the thing in action in the upcoming days.

Cheers,
A.