I am doing the "field testing" for a Transwarp-Card-like Accelerator.
The cards works fine in my Platinum, but not in my favorite IIe.
There, although the machine is accelerated, I get random characters on the screen. This depends on where the card is inserted. #5 and #4 give the worst results, #1 the "best" - but the machine is not really functional. If turn of the accelerator with a poke, the problems remain. If I remove the card, everything works just fine.
The IIe in question is a bit of bastard: It has a Rev. A motherboard (no double-hires, alas), the case and keyboard from an Enhanced IIe and an enhanced chipset, that is: 65C02 plus new ROMS.
The machine is in great condition. Power supply has been refurbished, all the usual tests work just fine.
Any suggestions would be greatly appreciated.