I am currently testing an Asus PVI-486AP4 mobo rev 1.6, with an Intel 80486 DX2-66 (CPU code ID of SK080) in it. When the BIOS POSTs, it says that the CPU is a DX4 100. If I try another Intel 80486 DX2-66 (CPU code ID of SX955), the mobo won't POST.

Reading the manual (downloaded from the socket 5 section on the Asus website), jumpers JP17 & JP18 are used to set the type of CPU. I've tried these two settings -

JP18 = 23,45
JP19 = 12,34

and also

JP18 = 12,45
JP19 = 12,34

ATM, jumper JP17 (which is used to set information regarding DX4 CPUs, and also cache type) is all set to "open".

Also, if I insert RAM in to SIMM slot 2, the mobo will not POST. Curiously however, I have RAM in SIMM slots 1 and 3 only, and it POSTs OK.

I would like to try a 486 SX 33 CPU, but I'm a bit worried that the mobo may try and run it too fast, and damage something.

As always, any comments will be very gratefully received. 😀

Edit: I decided to take a risk, and install a 486 SX 33 (CPU code ID of SX797). It worked. The mobo POSTs, and correctly reports information about the CPU.

Edit 2: I just dug out another 486 dx2-66, this time with a CPU code of SX911, and this one seems to work - the mobo POSTs, and also displays the correct information for the CPU. I also tried a 486 SX 25, and that was OK too.

Oh well. I'm happy with that. 😀