I need to think about the best course of action for a while. I'm tending towards making a crude in circuit tester. This would not be able to push the DRAM to its timing limits, by far. But at least indicate a gross fault in a memory cell.
Oh and I also need to get a very fine Dremel.

Another idea is to pull off the FRJ from the orange card and use it as a replacement on the other one. This way I might have at least one working card. Unless of course that has issues with the RAM, too. Which, given how these have been mistreated, is very likely. And pulling any of those big ICs off runs the risk of damaging them. So I'd very much do as little IC swaps as possible.

Systems posts and boots up, but no image on the screen. Really curious.

As to this: get a fine enough Dremel tool, attach new wires to the internal die to pin connections, hold it down with epoxy, then I can solder it back on. I suppose it helps having it off the board now.

Due to the chip shortage these things have more than tripled in price (as did a lot of things)

Hello World

Oh man, that's going to take some time to explore all that.

I put the rabbit hole that is the FTDI aside for now and entered a different one instead. Talking to my scope.

The documentation is the finest chinglish. They are trying to say it's a Ones' complement.