I bought some broken VLB (very long bus) cards from my favourite recycler in the UK:
The Cirrus Logic card was supposed to have bad RAM but it was a disappointingly easy fix, it was missing the jumpers that select which RAM bank to use. Without those it's impressive it worked at all but the sellers pictures showed it giving garbled output. Gonna have to test it some more to see if that was all that's wrong.
The Trident TGUI9440 VLB card was much more interesting though - visually the card all looks fine although I resoldered the QFP for no good reason, when inserted the computer would start up normally but no video output. It wasn't giving the "no video card detected" beeps and was instead booting up into the usual BIOS error for FDD because this board isn't set up yet.
No output from hsync or vsync on the VGA connector, but using my cheapo £20 oscilloscope I could see that the crystal was oscillating, albeit at a frequency that the cheapo oscilloscope couldn't hope to get a good read on.
So I thought I'd try the BIOS - it's a Trident card just like this one I fixed a few weeks back: Re: What retro activity did you get up to today?
But this card has a regular EPROM and I Think the seller got caught in the same trap I did where the BIOS file from vgamuseum is read out from the OS rather than the physical ROM. On many of these Trident cards the real ROM contents are garbled when read out on a normal EEPROM reader, but the computer reads the EEPROM just fine when it's on the card because they rearranged some of the address pins. There's not a good source for Trident BIOS files that I could find but I seem to have lucked out in that someone here 5 years ago uploaded the ROM from a Spea Vega Pro Trident card which has a closely related TGUI9440A. Thank you for sharing that, if you still read this forum 😀 looking for Bios Dump of the VLB Trident 9400cxi
The Trident BIOS files I've found are not picky, the versions (A5.2 / A5.4 etc) cover a couple of chips each, so I don't think exact revision or maybe even VLB/PCI are that important, since that Trident ROM that the card usually have should be pretty generic to keep costs down since it's a mask ROM.
I also found I had a Trident 9440 PCI card and desoldered / read out the rom from that, so here's Trident BIOS Ver A5.4 which I know is a good readout:
Because I found the closer match BIOS in the other Vogons thread I haven't tried it yet, but it should work I think.
Glad I wrote down how to put an EEPROM where a 27256 goes since I didn't want to research that twice. I was hoping to use the UV EPROM that the seller included with the card but none of the UV stuff I have gives the right ~250nm - I wish I had a lamp like the one a couple of posts back but I need something much smaller and more robust.
The card fired right up with no display glitches, now to test them out more fully once I put this motherboard back into a case and add some more peripherals.