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Huge unidentified ISA expansion card from IBM Industrial PC

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phreakindee

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I'm stumped. Help!

I've got this giant ISA expansion card set from an IBM 7532, an AT-class industrial PC. I can't figure out its purpose and am so far having no luck looking up the IBM P/Ns online or in any old documentation I've found. Only a vague listing or two on old parts distributor websites that don't describe it at all.

There's a label on the top of the 7532 that describes two cards as "channel adapter" and "bus power dist."

Album of pics:
https://imgur.com/a/4ubhmDk

I've included close-ups of the massive "channel adapter" card and the smaller power dist(tributor?) card. The power card connects to two of the computer's power cables that are normally used for powering hard drives and the like, P11 and P12 if I recall. And the label also says not to use the next two slots over so I assume it's drawing enough power to make using those risky, but I'm only guessing.

I've booted the PC but so far that's provided very little info. It boots the same as any other IBM AT from the period and my AT advanced diagnostics disk hasn't shed any light either. Unfortunately the machine's hard drive, if it ever had one, is long gone so no clues there either.

Thanks for any assistance, folks!
 
The card has 128K of SRAM and three high-speed FIFO chips on it, so whatever it was built to do involved shoving data around very quickly.

If you don't have the thing it's supposed to connect to the question is probably academic. Do you have any idea at all what the machine did in its previous life? The words "Channel Adapter" make me wonder if this could have been the control box for a mainframe and that card was used to firehose microcode or whatever into it at boot time, but that's a guess pulled out of the thinnest of air.
 
Maybe you don't want to do this, but out of curiosity: if you peek under the labels on those chips with the tape on top is that all a big mess of PALs/GALs/Whatever-Programmable logic?

Not that knowing that will make it any easier to tell what the heck it was for, probably just make it worse, but if they all are that's darn impressive. Could probably implement a whole CPU with that many.
 
man, that thing is an absolute UNIT.

I'd have a poke around on the large pinout connector. If its something standard, it could lead to what it was designed for.
 
The power card makes no sense. It's taking the 5V and GND pins on a standard ISA slot and converting them to standard power Molex sockets (or vice-versa). It's not drawing from the bus because the Molex plugs are the wrong gender for something like a disk drive or for powering a card. At the same time though there is no point to use a card like that to boost the maximum current rating on the ISA bus by adding more routes from the power supply as whatever load you are running that needs that much power would toast the backplane/edge connectors between the two slots. A passive backplane (or any ISA backplane for that matter) will supply 5V anyways. If you needed more power than the bus could supply you just added Molex plugs to the card.

Also fun fact. You can typically spot an IBM part number by the fact it's two numbers, a letter and four numbers. (EG: 12A1234)
25F8935 matches that qualification, so whatever ends up referencing that part is likely a solid clue.

What is interesting is the MOUNTAIN of PAL's and GAL's it uses. They went through the effort to develop something that uses that much logic and fit it onto an ISA card, so why not just develop it into a much smaller FPGA and save on board space/layout engineering? Xilinx for example had FPGA's on the market by the early 80's and if the date codes are correct than there was several FPGA's available by the late 80's.

I'm with the others on this. The card is part of a system that was being used to emulate a peripheral, quite possibly some sort of an ethernet bridging device or for allowing connectivity to products that supported Ethernet. My blind shot in the dark is the data channel its interfacing to was BUS/TAG by means of an external box which makes attaching the enormous cables more practical. These products do exist and were manufactured as late as the PCI era, for example this ebay link
If this was FICON/ESCON the interface would be significantly smaller.
 
I had already tried looking up the part number 25F8935 and the only hit comes back as " IBM PCB IBM" ... we already knew that haha.
 
I looked through the tech reference manual and saw nothing even remotely like this card mentioned. There were some oblique references to some “data acquisition” cards that maybe sounded promising, but I was able to find them in a contemporary listing of IBM Personal Computer Family products and it’s definitely not one of those.
 
It’s probably a 8232 LAN channel station, if my google-fu is working well today.
 
jafir said:
It’s probably a 8232 LAN channel station, if my google-fu is working well today.
Click to expand...

That looks like an excellent guess to me. There’s a bazillion page manual for that on bitsavers that unfortunately does not include any pictures of the S/370 channel adapter card because it says hooking the box up the mainframe is the job of an official IBM service engineer, but the card sure looks the part.
 
Looks like someone on his Twitter post came up with that suggestion much earlier than me. That person actually owns one so maybe he’ll open it and confirm.
 
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