I know Rob Taylor had begun work on reverse engineering a board, but if anyone has a dead one they want to strip and scan, send it my way to replicate it ;)
One thing i thought of throwing out there was this: https://www.mouser.co.uk/ProductDetail/Microchip-Technology/LAN9218-MT?qs=%2Fha2pyFaduh7GoBaJaS3j52JXXhN34TMMTgkdc1u3tA%3D & https://www.mouser.co.uk/datasheet/2/268/MCHP_S_A0003010310_1-2520859.pdf
Generic 32-bit interface (not for PCI), and...
For me, it's an Acorn 3010 or 3020 — hard to find one for a decent price these days, that's not been destroyed by the power of Varta battery explosion.
Funny you should ask, our school had RM Pentium 3 PC’s based on the AOpen (remember them?) 440BX boards and most had a 3dfx Voodoo 3 AGP in them (a few had Riva TNT2’s) and there never seemed to be any issues, on Windows 98SE.
I've had decent enough luck with my OWON SDS1104 - the lower end version is quite cheap for basic stuff: https://www.owontechnology.eu/product/1365126/owon-sds1022-20mhz-2-channel-digital-oscilloscope
https://wiki.preterhuman.net/Mac%27s-a-Million#/media/File:8CEBC8C8-E6D4-4C86.jpeg might be a good starting point, visually - looks like if it's populated the jumper at JB1 needs to be OPEN rather than closed?
Hi @cannfoddr ! This looks suspiciously like a video RAM failure - 1/2 the screen frame isn't being drawn - i'd recommend desoldering the chips at UB10 and UB11 - those are the 41264 DRAM's for the video system. I'd also check UF8 - the 74LS166.