OEM or aftermarket PLUS cards, what do you have?

[RetroGaming Roundup]

The aftermarket PLUS cards are insanely rare, the two manufacturers I recall from back in the day were PC Enterprises and Infinity Computer and I have seen nothing on ebay in the decade or so I have been looking. I did stumble onto an Infinity memory expansion when I bought an HX for parts. It is different from the OEM one in that it only has one PLUS card connector and uses about 20 individual ICs to handle the addressing and DMA functions that the factory uses an ASIC for. I am still hunting for the VGA and Hard Card ones, maybe one day. What do you have for your EX/HX?

 

[Eudimorphodon]

Wow. That memory card is sure a thing. Sure seems like an awful lot of support circuitry for four little RAM chips. If by any chance that came with a manual that has the schematic in it I'm sure there's some people who'd love a scan of it.

(I wonder why they omitted the second passthrough connector on that...)

Only Plus card I have for my EX is the 1200 baud modem, 25-1018. I really wish whoever bought the machine originally had gotten a serial card and an external modem instead.

 

[RetroGaming Roundup]

No manual, but a scan of the board itself should get somebody mostly there, and the chips are fairly available. If someone wants a scan just ask.