It’s either a Micronics on Anigma motherboard I forget which one. I had the 4sx-25 growing up.

From what I can remember, it only takes 4MB or 16MB Simms, I think theyhave to be parity. It takes only 5V CPUs so for a DX4 you’ll need the overdrive variety so the jumper doesn’t matter it’s controlled by the CPU, nothing to set on the motherboard.

There used to be a site, it’s still on archive.org. Search for “ spirit of performance ben myers”. I think that is how his name is spelled. He used to sell upgrades and had tons of info on older Gateway 2000 computers.

You have the cache already which was the hardest part for upgrades on these boards. The smaller cache chip is a weird 64kx1 or maybe 16kx4 dirty bit cache. It says DB on the board I believe.

I still have this machine along with original manuals and software and drivers on 5.25” floppies. Problem is it’s half way across the country at my parents house. I’ll get around to archiving and uploading eventually but I except it will take years.

Hey thanks for the reply! I did get it up and going. I found a 486 Overdrive CPU I had picked up for $10 at a swap meet a year or so ago and it was an easy drop and replace, and had a few 16MB SIMM's around it seemed okay with as long as it had the 4MB SIMM in the first bank, so it's now at 36MB of RAM

The IDE controller on this motherboard leaves a lot to be desired performance wise, so i've just put the CD-ROM on the SB32 IDE port and it's working so far, i've currently got an 8GB drive with OnTrack in it, It came with a 500MB IDE Maxtor drive that only boots 50% of the time, so i'll get another period appropriate drive for it, as this one has a 528MB limit due to the BIOS being so old.

When running Windows 3.11 it seems to stall out a lot but I think that's because i'm using the drive overlay software.. once I get a drive it agrees with size wise, i'll try it again.