Thus far I managed to track down enough specs to locate a ribbon cable that works with the panel. I've got a box of the suckers, so I can now plug stuff into the LCD. The problem is, the contact points on ribbons are extremely tiny (1mm pitch on this particular ribbon) so it's not really practical to go pushing current through the pins to see what happens.
Up until now, my solution has been to basically take a razor to the ribbon and slide it up, making each contact separate and more or less accessible. For best results, I've soldered extra bits of wire to the shredded ribbons so they're actually manageable. This lets me get current through the cable, but it's extremely awkward, and I still haven't gotten around to properly arranging the 8V power supply needed for the LCD panel itself.
Tonight I hunted down the original Molex connector part number for the connector that appears on the LCD (not too hard; I had it already from finding the cables). This turned up enough specs to find similar parts. So I just ordered a set of 5 connectors that should match the ribbon cable, and give me a reliable set of pins to experiment with and/or hook up to a testing breadboard.
Oh, I discovered a fast way to trip mains breakers: apparently, if you wire the leads on old AT-style power switches wrong, they short out the entire PSU. Whoops. Fortunately, it looks like the short is before all the impossible-to-replace fuses and such, so once I get over the shock of seeing bright blue sparks mere inches from my hands, I'll give it another shot and see if the PSU is still alive.
I also discovered that 9V batteries do not produce enough amperage to drive the inverter in a backlit LCD.
These has been your fun-facts trivia session for today.
Update at 3:40 AM
So I got all obsessive about finishing up the AT power switch, and got it working. The AT supply belongs to an old Pentium box I had laying around (and forgotten about); a long time ago the PSU fan crapped out and I cannibalized it for spare parts. Since rediscovering the machine, I decided it was a perfect candidate for my nostalgia-gaming-PC project, which basically involves playing a lot of old DOS games on actual DOS and not mucking around with all the poor emulation it takes to run them on XP.
That, and to be honest, I'm curious how challenging I'll find the old mid-90's hardware minefield to be with all the added years of experience I have under my belt now. Should be interesting - and, since I'm a psychotic masochistic freak nerd, it'll also be fun.
It took a lot of cleaning and hunting down loose screws, but I eventually managed to get the PSU fixed up with a new, working fan, and reassembled. For a while I was worried that it was blown up, since I kept powering on the machine and it wasn't giving a POST beep. More worryingly, the CPU fan wasn't spinning up. As far as I could tell, the motherboard wasn't receiving power.
Finally, it dawned on me that the CPU fan had no power wires. It wasn't spinning up because it wasn't connected to anything. I disassembled it and found that the wires had apparently quantum tunneled into another corner of the universe; the solder contacts on the fan were pristine, no sign of ever having been wired up. But I know for a fact that it once had wires, because I recall being annoyed by the loudness of the fan last time I had the machine running. Since I had the thing apart, I gave it a shot of WD40 and soldered on a little hack-job set of wires so I could plug it in.
Let me tell you, reassembling an AT case is not fun. The power switch is mounted in a totally weird way, there's not enough room for the sickeningly massive heap of cables that have to be crammed into that tiny box, and half the screws were missing. It took quite a while to get it back into some shape that vaguely resembles a computer.
In the ravaging of my stores for spare parts, I discovered over 300MB worth of old SDRAM, which I dropped into the box to replace the 16MB of EDO that was in there before. It now sports an astronomical... 64MB of SDRAM. Apparently, the motherboard can't address more than that.
But the box is POSTing cleanly, and everything seems to be in workable condition. I still need to find an old hard drive, CD drive that can be run with DOS drivers, and a sound card. I've got an Audigy that I'm not using anymore, but I'm worried about the DOS-driver situation. I used to have an original Sound Blaster 8-bit card, but I don't know where it is - I shall be distraught if it is lost.
Oh, and during my POST run for the box, I realized something else I need... an AT style keyboard. Now that should be an interesting challenge to find.
Dunno about USB keyboards.