It's easy to open (this image came out blurry, but I'm just using it for navgiation)
We've got two terminal connectors on the left, plus a 3.5mm audio jack. The right has a USB port and a barrel jack power connector.
Chip info here:
Also, I was wrong. Apparently it goes up to 64 megabytes of RAM:
There's three 74HC139s, which are dual 2-to-4 line decoders.
This maybe is used for wiring up one of the expansion ports to the ISA bus?
It's a 60 pin connector. 8-bit ISA is 62 pins, 16-bit ISA is 98 pins.
So if they just merged some grounds, 60-pins is totally doable.
@LionsPhil no, unless you bitbang some PWM out of the PC Speaker (like lots DOS of MOD-trackers, and some games - e.g. RealSound - used to do). But that will sound very bad on a piezo.
Also: this is a 386*SX* (16bit, no cache) so Doom is already stretching it.
@indigoparadox Sierra's EGA games(running on SCI0, starting with KQ4) definitely worked this way: each drivers (AdLib, MT-32, etc.) loads custom settings and instruments, and then the game played MIDI notes mapped to those.
In later games (eg. SQ3; or running SCI01, eg. QfG2) the music driver could intercept these MIDI notes and play samples instead, before the engine supported proper samples.
ID software games tended to be closer to VGM and streamed complex register settings
@LionsPhil @foone I don't think anyone ever previously shipped a sound card with a 4-op OPL3 but no PCM sample support.
The Adlib had an 2-op OPL2.
The Sound Blaster, et al, had PCM sample support.
@foone I wonder if they have a license for that Win95.
I wonder if Microsoft still sells licenses for it.
@foone https://de.aliexpress.com/item/1005005542582463.html?gatewayAdapt=glo2deu
This shop page should shed some more light on the ISA 8 Bit extension Interface as it have the pinout
@foone appearently there is a external ISA „expansion“ with 3 card slots you can buy for $20
https://de.aliexpress.com/item/1005005543239919.html?gatewayAdapt=glo2deu