Been trying (and not yet succeeding) to help get a board working, but came across a set of boards on Ultimate Retro that might help with an edit. The boards are:
https://www.ultimateretro.net/en/motherboards/6714 -listed as ATRONICS INTERNATIONAL, INC. Master
https://www.ultimateretro.net/en/motherboards/5461 -listed as Impression 786 ACIO VESA MOTHERBOARD
https://www.ultimateretro.net/en/motherboards/9801 -listed as Unknown "MASTER REV.A-3" (says 72 pin SIMMs, should be 30 pins)
https://www.ultimateretro.net/en/motherboards/5462 -listed as Impression 786 ACIO VESA (VER. 2)
All 4 boards are very similar, marked as "COPYRIGHT 1993, MASTER REV.A-3, U.S.A.", but the jumpers around the 386 socket are slightly different for the first two compared with the second two.
Crazytiti has been able to read their BIOS, and their board looks like it matches the layout of the first two: http://crazytiti.free.fr/divers/AMIBIOS%20486 … 115%20c1992.rom
They all have the USA SC-9204-A chipset, with slightly different interrupt chips (UMC UM82C206F on the Crazytiti's, SIS 85C206 on the "Unknown "MASTER REV.A-3"").
BreakPoint has a very similar board, except it's marked "COPYRIGHT 1992, MASTER REV.B, U.S.A.": http://f5soft.com/pics/2019-11/1.JPG . So a year earlier, but revision B rather than revision A-3. Jumpers are a bit different, but apparently the BIOS from Crazytiti's rev A-3 has worked in the B. It also has the SC-9204-A chipset, but with a Samsung KS83C206Q.
Maybe all of the interrupt controllers are pin compatible (UM82C206F, 85C206, KS83C206Q)?
[edit: Oh, and I think all entries should have an 'also known as' "MASTER REV" for people searching on that]
Threads:
Looking for bios for USA Integrations sc-9204
Try to fix old 786 ACIO VESA 386/486 Motherboard
Not sure how best to proceed here. It feels like there are 3 versions of the board: the first pair (REV.A-3), the second pair (REV.A-3 ver 2) and BreakPoint's REV.B. So maybe the "ATRONICS INTERNATIONAL, INC. Master" should be folded in to "Impression 786 ACIO VESA MOTHERBOARD", along with Crazytiti's photos, and "Unknown "MASTER REV.A-3"" folded in to "Impression 786 ACIO VESA (VER. 2)". And a new entry for BreakPoint's board. I don't know where the name Impression 786 ACIO VESA , or ATRONICS, is coming from, so based on the manual (see just below) maybe "786 AIO VL-BUS 3486 MASTER REV.B". Bit of a mouthful, but should help for people searching on when that can see on the board silkscreen.
Mind that the Atronics entry does have a BIOS string listed: 40-1200-00156-00101111-060692-USA-9204-H. Which doesn't match Crazytity's (in particular the manufacturer code): 40-1200-001805-00101111-060692-USA-9204. So who knows if they are actually the same board.
Lastly... The manuals given for download for both the 786 ACIO boards looks to actually be for BreakPoint's board, based on the location of the jumpers and the 14.318 crystal in the manual's diagram. So that should probably be attached to that entry, and maybe a note on the other two that a manual for a similiar board is available. The MTL jumper page for the non-Ver.2 and the TH99 page for the Ver.2 do seem to match, so they should stay where they are.
And I've just realised that that manual has a pinout for the SC-9204-A, which might be useful.
[edit: oh, and maybe they should all have "MASTER REV" as an 'also known as' for people searching for that]
