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What 486 mainboard is this?

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First post, by Kouwes

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I got this 486 today but I don’t know much about it. It‘s a weird PC with a PS/2 mouse AND keyboard connector. There was no cdrom drive, only a 3.5“ and a 5.25“ floppy drive. The harddisk is a seagate ST3120A with 107MB. I only connected the HDD to test the PSU and I got 5V so I guess that‘s OK for now.
The mainboard has an onboard WD90C31A graphics chip.
The barrel battery was just starting to leak and was removed just in time it seems. I still need to remove the board from the case, so there may be a nasty surprise waiting for me…
I don‘t know what CPU is installed because the ZIF socket has this u-shaped lever that gets blocked by the heatsink - clever! 🥳
I‘m going to clean up the corrosion and de-solder the battery pins. Good thing the board has an external battery connector!
Well, maybe someone recognizes this board?

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Reply 1 of 3, by rasz_pl

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I was going to say PCB looks very ACER like and then I saw AMBRA on BIOS chip 😀 Its one of IBM value sub brands outsourced to ACER
https://www.youtube.com/watch?v=4HjqQr177q4 AMBRA: The Forgotten PC Brand from IBM The Serial Port
https://www.youtube.com/watch?v=vapy4916iUA IBM's Ambra, What Went Wrong? Dinty's Hideaway

Edit: might be Ambra Hurdla 486. Cant find any pictures of one inside, but all the others dont fit

Reply 2 of 3, by Kouwes

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Thanks for your reply!
I also discovered the story behind Ambra. Still haven’t found the manual for this particular board/pc but I don’t think I‘ll need it.
I removed the board and it appears (looking at the jumpers) it has 256kB cache and a 486DX50 cpu installed. Now I just have to add a soundcard and probably a CF adapter and the PC is good to go.
My only ISA soundcard left is an Aztech PnP but it has an OPL3 so I guess that’s ok for Dos6.22.

Edit: uploaded the wrong picture 😄

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Reply 3 of 3, by BitWrangler

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You might find something of use here...
https://www.praxis8.com/ambra/default.htm

Ambra fell down the cracks a bit with IBM support, it was treated as 3rd party support, and IBM didn't really have support "on the web" until after they were discontinued, then by the time most things like the PC-BBS were archived from 97-98 they'd deleted 3rd party files as having expired from being their responsibility, so what's around is very very patchy.

Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.

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