And the answer is.... a 486 sx2-50 I would never have guessed

Hi, I'm going through my old CPUs and there's one I can't figure out. It's got the same pin layout as my TI 486 dx2-66 and DX2 Overdrive. There's a heat sink glued very firmly to the top. Underneath there's a few details: 94134186AB MALAY FD 427 INTEL 89 92 Searching these numbers using google …

I think this counts as a hardware issue, I've got 4mb of RAM but the RAM counter at POST only goes up to 3,968kb. I'm guessing that I've got the BIOS being shadowed in RAM, which I think is done because accessing RAM is faster than accessing the BIOS. My question though, is how much is the BIOS …

I added 256k of l2 cache to the motherboard of my 486. Next upgrade will be an additional 4mb RAM, and then I'll think about getting an extra 512kb of video ram.

I'm posting a new topic each day, sorry if that's tiresome but each topic is slightly different yesterday it was graphics RAM, today it's cache :) My motherboard has 9 x 28 pin sockets that are marked 32Kx8. I think this must be cache ram modules. 8 of them are all grouped together, and one is just …

I tracked down information on the number of cylinders, heads, and sectors on my Seagate ST3120a, attached a GoTek and fully booted my 486sx for the first time. I have now installed Dos 6.22 and Windows 3.11, Next I will track down the floppy disk images for a CT2800 (Soundblaster 16) and try and get …

That's great, thanks. I assume these chips aren't still in production?

On the motherboard of my 486 there are 4 x 20 pin sockets labelled 44256. I think that these are probably for adding video ram - they are close to the onboard graphics chip (WD90C30-ZS). Doing a search there are people selling chips which look right on ebay, but I'm unsure about what variations …

Thanks, this is giving me confidence (hopefully not too much) 😀

Thanks, I see a DS12887+ listed as available - but without a datasheet for the TH1287 I'm concerned that there might be unexpected differences, but I might give it a try.

I've looked, but given the (understandably) scarce documentation of an obscure chip in an obscure motherboard I think my first preference is to resuscitate the chip I have. Either way I'll need to de-solder the chip that's there at the moment. If I replace it with a socket then at least things …

Having kept an eye out for years I've just got hold of a PC that's the same as my first one, a Commodore 486sx-25. There can be fewer safer ways of having a mid-life crisis :). It powers on and goes through the POST, but won't proceed any further. It won't go in to the BIOS settings, though it does …