Win3x.Org

This one was already discussed here:
https://www.vogons.org/viewtopic.php?p=914210
According to this thread, manufacturer seems to be BIOSTAR.
It looks very close to the SOYO SY-015G:http://www.win3x.org/uh19/motherboard/show/4655
Only very little differences, just like a different revision.

After neutralizing and cleanig the battery lye, as always, I looked for damaged traces.
Like often, one of the keyboard lines (data/clk) was interrupted.
After fixing it, I powered it up, but there was a strange behavior.
It did not recognize keystrokes, although no keyboard error was reported.
With no keyboard connected, a keyboard error was displayed.
The battery lye also killed a via in the keyboard IRQ line, so the POST found the keyboard, but the IRQ did not get through.
It took me a bit to find it out. I first soldered out and socketed the keyboard controller and the 74F245 that buffers the keyboard lines, just to find them OK.
You can see the fixes on the pics.

Board dimensions: 220 x 220 mm
BIOS version reported: MB-1340MKA-F
BIOS ID: 30-0200-001223-00101111-111192-MXIC-0
BIOS (27C512 EPROM): http://www.filedropper.com/mb1333

The logo on the ROM, the POST string and the motherboard's name make it all clear : it's a Biostar motherboard

added:
http://www.win3x.org/uh19/motherboard/show/8434

when you say very close to that Soyo board, is that close enough to recycle the manual for this board?

Although it looks very close, the jumpers slighty different in numbering an positioning.

Ah, so not a 100% match. Oh well, it is listed now, maybe a manual will show up. They do for other boards, basically out of nowhere.