(at least in terms of user's manual and BIOS dumps) here's some info on an ABC Computer Company Single Chip 80286 A3263. 
Manufacturer name:
ABC Computer Company, Ltd.
As far as I can see there is no mention of this manufacturer anywhere on the board itself or in the manual. But it is listed on Total Hardware (and others) under that make. So I copied that.
https://pcrebuilding.altervista.org/49/ ... 3+286.html
Motherboard name:
A3263-01 Rev 3.1 (Printed on PCB between ISA slots)
Motherboard schema:
Baby AT
4 x 16 bit ISA
2 x 8 bit ISA
even / odd BIOS
Supported memory:
SIPP RAM x 4
Max 4MB
Supported CPUs:
PLCC 80286 @ 16MHz
Manual(s):
Motherboard BIOS(es):
Picture(s):
http://westarps.de/temp/PpmUy2sbApBdRG2 ... 0A3263.zip
Trivia:
Removed from a half height (ISA riser board) desktop case with a FAST sticker on the front. The motherboard manual mentions a power supply wattage and shows various desktop / tower cases in detail. There is the same FAST sticker on one of the ISA slots. So this board apparently shipped as part of a pre built system.
I have two of these boards and both have a full size protective transparent plastic sheet hot glued to the back.
There was a barrel battery originally but it was clipped off of both boards by the previous owner.
There is a pocket in the manual for a 5.25 inch floppy with EMS driver. Unfortunately it was missing.
