These are OEM boards made for the OEM by FIC/Acer.

Not clear what you think to gain by knowing the exact board, you can just read the pictures. No idea about the FIC/Olivetti, but the IBM:
- OPTi Viper chipset
- 4x 72p SIMM, probably with 8MB in each slot for total of 32MB
- slot for cache (possibly COAST, but second slot reeks of a more proprietary solution) but none installed.
- onboard I/O care of the SMC chip. 2x IDE, 1x FDD, serial and parallel - and 2x PS/2 on the LPX backplate.
- Trident TGUI9680 with 2MB DRAM

The OPTi Viper was an early Pentium design with poor performance and lack of cache will only make it worse. However that shouldn't be a big problem in DOS. Would work fine for later DOS games. I'm no big SB16 fan (Vibra or otherwise), but exactly how bad the card is can be determined if you look up the CTxxxx model number and check here: Sound Blaster: From best to worst

As for the Olivetti/FIC, I can't find anything on the "VT486-VC", so can't really comment. Sure that keyboard interface isn't just DIN? In which case it's electrically compatible with PS/2, so not an issue. 486DX-33 is about the sweet spot for early DOS games if the board has a turbo-function to slow it down to XT levels.

Thanks!
Yes, keyboard port is DIN, so I'll get an adapter for it.

Therea are two CTxxxx numbers on the card, one on the PCB and one on the chip itself, but I don't see them in the list.
PCB: CT2800
Chip: CT2504-TCQ

The problem I have now is that the CPU fan and PSU fan are horrendously loud and noisy!
The 486DX33 build is much more quiet.

Anyway, thanks for your help!

Raph33BDX wrote on 2022-12-25, 19:48:

Thanks! Yes, keyboard port is DIN, so I'll get an adapter for it. […]
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Thanks!
Yes, keyboard port is DIN, so I'll get an adapter for it.

Therea are two CTxxxx numbers on the card, one on the PCB and one on the chip itself, but I don't see them in the list.
PCB: CT2800
Chip: CT2504-TCQ

CT2800 is on the list (the order is more logical/chronological than according to model number, so easy to miss one). It's an early Vibra. Good news is a real OPL3 for early DOS and low self-noise, but beyond that about every bug you could get: both kinds of MIDI hanging note bugs, slowdown when playing 16b audio and MIFI simultaneously and those nasty Vibra clipping/ringing/hissing sounds.

Still, back in the day it would have sounded impressively better than the PC speaker...

The problem I have now is that the CPU fan and PSU fan are horrendously loud and noisy!
The 486DX33 build is much more quiet.

So, fix them. New 40mm CPU fans can be bought new. PSU fan is slightly trickier as you need to open the PSU to fix it. You need to be confident operating around high-voltage capacitors, but if you are, it's simple enough to remove the old one with worn-out bearings and put in a new one. I like to use Noctua (Redux) fans for the purpose as they are very quiet but still manage to move a decent amount of air.

I've ordered a new fan for the PSU. Quite easy to replace, and I have some suitable tools to access connectors etc so should be ok.
Thanks!