At the bottom of the image I can see a bunch of stickers. The right one looks like a model number: SB300SX2. However a google search comes up with nothing. Is there anything on the back of the board? Maybe FCC ID or something? Since it only has 4 ISA slots, and a lot of integrated hardware, such as graphics, FDD, HDD controller, parallel and serial ports, I guess it was used in a compact desktop machine.
The photo looks like the board is in a case? Does that tell anything about the manufacturer?

Indeed, I checked all the stickers in the front with no info turning up.
When I get home, I'll remove the board to look underneath it.

These are the cases:

The badge on the front says: Intel 386 Microcomputer.
There is a sticker mentioning Intel too on the backside of the case but didn't check it thoroughly. At least one number didn't give me anything either but will look into that too later on.

Took some more pics but none gave me something I could use. Even the 3,5" drive is Intel.

I tried to change the values of the drive but still nope. And of course the drive that was in the machine,doesn't match the values in the list. I wanted to look in the BIOS of the other PC (where it was in), but a tantalum cap blew up so that one is also ruled out ATM.
Any advice on how to do this would be highly appreciated!

Murugan wrote:

http://i.imgur.com/hvM71qJl.jpg […]
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That FCC ID EJM5Z8S300SX proves this machine is definitely an Intel product, as EJM is a prefix assigned to Intel.

Looking up the ID leads to this registration from August of 1989.

Also found maybe that exact model in an InfoWorld writeup from June 1989.

I'm trying to figure out what the chipset is... can you make out the part number on U88 next to the CPU?

You mean at U87? Isn't U88 the SX-16?
U87 is:
http://www.cpu-world.com/sspec/SX/SX310.html#comments

And indeed, that's the model!
So weird that there is almost nothing to be found about this PC. You'd expect Intel to document it more.

My biggest question is now: how the heck can I enter the correct HD setting in the BIOS??!!
Yesterday I was able to install DOS 6.22 but I used one of the incorrect presets.
Rebooting did.....nothing.

After adding "Intel 300SX" with " I finally found some info!!!!!
http://www.frankshospitalworkshop.com/equipme … vice_manual.pdf

Seems this has industrial/medical use??

Sorry for the necro, but this is a regular Intel board from the 300SX-20 system.
https://www.ultimateretro.net/en/motherboards/10504

Back when putting onboard video meant doubling the size of the motherboard