mt777 wrote on 2023-01-16, 16:26:

Initially thought that will be Opal LX but it is something more interesting (ACER 1217 chipset instead Opti).
66M SLC2, soldered Cyrix fpu and ability to solder socket, Award Bios.

We have a winner!...I'm sure the Retro Web team would be interested in any info, pics & BIOS dumps for their database - https://theretroweb.com/motherboards/s/ibm-486slc2

Cool!
I initially checked the website but overlooked this entry (due to missing pic probably).
Jumpers described so in total we have everything...

PC Hoarder Patrol wrote on 2023-01-16, 19:59:

mt777 wrote on 2023-01-16, 16:26:

Initially thought that will be Opal LX but it is something more interesting (ACER 1217 chipset instead Opti).
66M SLC2, soldered Cyrix fpu and ability to solder socket, Award Bios.

We have a winner!...I'm sure the Retro Web team would be interested in any info, pics & BIOS dumps for their database - https://theretroweb.com/motherboards/s/ibm-486slc2

Thank you for spotting this thing. Info, picture & bios were added. mt777: credits are in the pic

Nice! Does it work woth the MR Bios for Ali 1217?

I tried for a while and seems that yes (but speed was not recognized as 66). Didn't check performance.
I prefer keep older award bios as I never can remember shortcuts with mrbios

Interesting mobo. I don't see 3V3 regulator, does the CPU run at 5V? Without any heatsink as well?

Also, not sure what the "known issues" on The Retro Web is about, this doesn't use Dallas RTC but rather a modern clone of good old Motorola MC146818A which needs external battery.

By default the CPU has a small heat sink. But it get really hot anyways.