Hi All,

Been reading this forum for a while now, an excellent source of information, and really have enjoyed my stay here.

Recently I built a Retro 486 Socket 3 SiS496 machine, however, I made a mistake and damaged it, blowing up the southbridge (dropped a screw into the open case while playing around with jumpers). This motherboard has now become a parts board unless I can obtain another 85C497 for a decent price (I am capable of swapping the chip).

Because I wanted to continue to play with this particular chipset I purchased another "tested" board from eBay with the same chipset, the KM-S4-1 and this is where this problem started. At this point I know that all my hardware is good and compatible, FP RAM, CPU, etc. However the BIOS won't proceed past the RAM test at power on, it gets to 640K on the memory test and hangs. If I enter the bios before the test starts I can see the BIOS is reporting that I have 2x the memory installed than I actually have. I have verified there are no shorts with the SIMM presence detect pins which as it turns out these boards do not even use as the SiS496 datasheet reports that memory is probed for size by writing and reading test patterns.

Further to this, if I swap out the BIOS from my damaged board (AMIBIOS) into this one (originally AWARD BIOS), I get resource conflict warnings, however, the system now detects the memory correctly and boots. This confirmes it's not a hardware fault, but likely a bad BIOS, however, I do not at present have a spare EEPROM to flash or the equipment to erase and program the UV erasable EPROMS these two boards came with.

I have ordered a programmer and eraser (I have wanted these for a long time now anyway), however as this community is full of very smart people I figured I would ask in case someone else has encountered this and knows of a possible solution.