Recent content by sitharus

After tracing out the boards the old nemesis Buried Traces has appeared. The data and address busses are obvious, as are most of the support pins, but there's a bunch of signals I can't be certain of as I'm fairly sure they're repurposed from the EDO use. These are the RAS and CAS lines...

I guess I know what I’m doing this evening :D Those photos look great, except for that I can’t make white ones now due to the trademark :LOL:. Looks pretty straightforward though, so I’ll trace them out and hopefully fire up KiCad in a couple of days.

Yes that would be perfect!

From what I’ve found so far the Motorola Starmax 3000/240 shipped with the 4MB vram module. I’ve only found one photo of the motherboard online and it’s good enough to show 4 QFP chips on the module which is exactly what I’d expect, but it’s top down so I can’t see the module detail. I’ll keep...

They're how the ATI chipset detects the type of RAM installed. With no resistors it must be EDO VRAM as that's all I've seen so far, you have to add pullup resistors to the DIMM so it can recognise SDRAM or SGRAM, This is from Apple's technical documentation on the PowerMac 4400, which has the...

There's a few too many buried traces on that board to follow without actually probing with a multimeter unfortunately :/ Any Mach64 VT board should do though, PC ones are the same chip. I'm going to keep looking through the second hand market and hopefully will find one, though it's a limited...

I know I’m resurrecting an ancient thread, but I’ve just been going down this rabbit hole myself! From what I’ve got so far the VRAM slot is pretty much a straight connection to the ATI chip and there’s no need for any glue logic, but it uses sense resistors on “specific lines” to determine the...