I just picked up this motherboard. It has an OPTI 82c481/482 chipset and Mr. BIOS. The only markings I can find on the board say KMC486-25 (C)1990
Any help would be appreciated. Thanks!
AST SixPack
That is a juuuge biii$#$#%.
Google saw one of those once, ebay deleted it long time ago https://images.app.goo.gl/8EzQZb1xm62kQc7r6 it was listed as "Vintage Full AT Dual Socket Motherboard 486 386 KMC 486-25 1990 ~REPAIR or PARTS"
KMC is Jamicon. Sadly theretroweb doesnt have one similar to yours. Closest is similar style https://theretroweb.com/motherboards/s/gigabyte-ga-486l and yes, this is 128KB of cache in 8KB chips 😮 lovely board.
https://github.com/raszpl/FIC-486-GAC-2-Cache-Module for AT&T Globalyst
https://github.com/raszpl/386RC-16 memory board
https://github.com/raszpl/440BX Reference Design adapted to Kicad
https://github.com/raszpl/Zenith_ZBIOS MFM-300 Monitor
Actually, that was the listing I bought. I bought it a couple weeks ago 🤣 It took a while to ship
AST SixPack
That's a nice looking board.
It looks like it had some battery leakage near the bios chip
Does it boot ?
Right to repair is fundamental. You own it, you're allowed to fix it.
How To Ask Questions The Smart Way
Do not ask Why !
https://www.vogonswiki.com/index.php/Serial_port
It had minor damage from where the Varta battery was, but it was easily cleaned up. It does post, but locks up when trying to read/write to a floppy. I need to find the jumper settings so I can configure it correctly, but this seems like a really odd ball board.
AST SixPack
ASTSix-Pack wrote on 2023-04-09, 16:08:Actually, that was the listing I bought. I bought it a couple weeks ago 🤣 It took a while to ship
haha nice
ASTSix-Pack wrote on 2023-04-09, 17:09:It had minor damage from where the Varta battery was, but it was easily cleaned up
I can also see some green inside ISA slot 🙁
but holy F$%$^ sixteen 30pin ram sockets, we are in NextCube territory here 😀
https://github.com/raszpl/FIC-486-GAC-2-Cache-Module for AT&T Globalyst
https://github.com/raszpl/386RC-16 memory board
https://github.com/raszpl/440BX Reference Design adapted to Kicad
https://github.com/raszpl/Zenith_ZBIOS MFM-300 Monitor
- ASTSix-Pack: Would you be able to dump the BIOS of this and upload it somewhere? Early 486 BIOS'es are a rarity.
It's a beauty.
"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium
