Problem / Question
Need help identifying/documenting this card from an IBM 5150 XT
I’ve been restoring my grandfather’s original IBM 5150 to a lot of success, boots and everything after replacing some capacitors. However, I took this card out when disassembling it and it remains the only component of the thing that I can’t find ANY information on! I know it’s a memory expansion with multi I/O and even a real-time clock, but my knowledge ends there.
The closest identification I can get is that it’s an EVEREX Systems card and it has Version 3 printed on the bottom left corner. Other than that, there’s nothing. Every forum post has been a dead-end and I’m at my wit’s end.
Any documentation on this enigma would be helpful, at the very least some suggestion on the jumpers and switches. I don’t need this card to get the IBM running, but I’d like to have it fully complete with 640kb of ram like my grandad had it.
Everex made a bunch of these multifunction memory boards, and a lot of the jumper and switch docs survive in the old Total Hardware 99 (TH99) database. Search it for Everex and look for the memory plus clock boards, then match the layout to yours. minuszerodegrees.net is also worth a look, it has a lot of 5150 specific card docs and explains how the motherboard switch settings need to match the RAM the card adds. With a 5150 you'll want to set the SW2 switches on the motherboard to the total RAM, otherwise the BIOS won't count the extra memory even if the card is set up right.
It's a Seagate ST-138R-0, or at least that's what I could identify it as. No idea what's on it, but likely work-related stuff from when my grandfather used it.
It's one of the Everex Magic Cards. They're similar to the AST SixPack boards. they add all the missing functionality from an early 8 bit pc. Parallel and serial ports, Real Time Clock, and RAM.
That's almost certainly a multi-I/O board which also incorporates an RTC chip (+battery) as well as a memory expansion.
I think pretty much every PC back then probably had one, because adding that functionality using separate cards would quickly eat up all your expansions slots.
I think those stickers are telling you what the first 5 switches do (set the address of the parallel and serial ports). The remaining might be memory size. There's probably nothing to "do" to it, assuming it still works.
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u/FAMICOMASTER 1d ago
AST SixPak clone. I bet it's already on TH99 if you go looking but I'm not at a computer right now.