I am using this board in 386 mode - I had mixed results with the different MR-BIOS available for this chipset, with "V037B302/UMC_302" working best. There are different versions of the BIOS for UM82C481 rev 0 vs rev A/B, my board has rev B (UM82C481BF). I have not tried this BIOS with the board in 486 mode. Sticker from Geekenspiel.

V037B302 UMC_302 386 WriteBack, Rev A,B *ONLY* (Not REV-0 !)