I have one of these cards-- https://theretroweb.com/expansioncards/s/a-trend-3dp4020
It only has 4MB SGRAM. I'd like it more if it had 8MB so I could compete for the all time low score on 3dmark 2000
Anyone know what the memory expansion daughterboard would look like?
Some of the traces are easily observed going to the headers on the top, bottom, and right side of the card.
Some of them are direct linkages to the chips on the card, so datasheets from those chips could tell us what those signals are supposed to be.
The BACK of the card has surface mount pads for 4 more chips, presumably of the same species. These also seem to have terminations at the IDC header strips at the top, right, and bottom.
Sadly, the routing is all kinds of spaghetti swirl in nature, and eye-crossing.
If you can get a better contrast image of one of the RAM chips so I can look it up, that would help. The existing images there are too low fidelity to read the chip markings.
Since there are 4 unsoldered pads, wouldn't be easier to find compatible memory chips and solder them on the back of the card, instead of looking for exotic expansion modules?
I have two permedia 2 cards, one pci and one agp, the pci card is 4mb while the agp is 8mb, I don't know if there are 8mb pci versions but the chip can address the 8mb without issues.
Ok, good idea. I’ll have to see if I can source some chips.
douglar wrote on Today, 11:05:Ok, good idea. I’ll have to see if I can source some chips.
It shouldn't be too difficult to find a donor card, buy a cheap card from ebay or r buy them from shady shops like utsource.
