Ok.. after spending waaaayyyy too much time scouring the web, most listings I saw for ones like this say it is an Axiomtek part, but I found one that was exactly the same, except without SCSI that showed a picture of the back.

The part number was NEAT-551 which is an IEI part. Looking on another page lists the similar parts, NEAT-553 looks to be the one with SCSI.

Still can't find a manual for it though. None of the archived IEI sites seem to have any of this model range.

Edit:
Found another pick of a different one, the NEAT-552. It had another sticker on it labeled NEATEK.

Did a web.archive.org search and came up with the NEATEK website.

It may actually be a NEAT-550, and not a 553.
https://web.archive.org/web/20010308214259/ht … 0/neat-550.html

If it is the 550, you can find the manual / BIOS here - https://web.archive.org/web/20040504060101/ht … ntend/download/

That certainly looks like it. Good find!

The manual doesn't mention anything about if power has to be plugged into the PWR plug or not. I'm kinda guessing it does though.

Most backplanes can use either AT or ATX power supplies and there were ATX power supplies that had the extra AT style power connector.

There were also AT power supplies that had that extra connector. I forgot the name of it, but it should be P10 from what I could find.

You can get ATX to AT with P8,P9,P10 and ATX to ATX + P10 adapters.

PC Hoarder Patrol wrote on 2021-11-23, 10:44:

If it is the 550, you can find the manual / BIOS here - https://web.archive.org/web/20040504060101/ht … ntend/download/

cyclone3d wrote on 2021-11-23, 03:53:

Ok.. after spending waaaayyyy too much time scouring the web, most listings I saw for ones like this say it is an Axiomtek part […]
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Ok.. after spending waaaayyyy too much time scouring the web, most listings I saw for ones like this say it is an Axiomtek part, but I found one that was exactly the same, except without SCSI that showed a picture of the back.

The part number was NEAT-551 which is an IEI part. Looking on another page lists the similar parts, NEAT-553 looks to be the one with SCSI.

Still can't find a manual for it though. None of the archived IEI sites seem to have any of this model range.

Edit:
Found another pick of a different one, the NEAT-552. It had another sticker on it labeled NEATEK.

Did a web.archive.org search and came up with the NEATEK website.

It may actually be a NEAT-550, and not a 553.
https://web.archive.org/web/20010308214259/ht … 0/neat-550.html
550 and 551.JPG

First of all, I cannot express how thankful I'm for helping me with that.
My SBC card is exactly the same, like the one above, but it has no SCSI connectors soldered. Not sure if it is a different model, but your linked manual (550) seems to be accurate about all!
In it, I found a power connector diagram

So it looked like P8 power connector from AT PSU.
So I connected it, along with VGA and... it worked!

Looks like MMX, so a little too fast for my project 🙁 I would rather have something like 486DX4-Pentium 166 on it 🙁
I was thinking about getting like 3 slots backbone with such card, and putting it into case like this What did I just bought and how to use it? thread.

I still have to figure out that connector, or just replacing whole display in it, and get backbone for it, but one day I will