Try posting without the CPU cache and then enable it with a command line tool. For example ICE.EXE or THROTTLE.EXE.

You might already have these tools.

It might lockup, or it might not...

Thanks, I'll give that a try later and see how that goes, maybe it just gets stuck on that screen and I could re-enable the cache with autoexec.bat,

Yea you never know 😀

I had a similar problem with a different board: 486DX4 Overdrive no boot

It seemed that no cpu with more than 8kb L1 cache would boot on it. AMD DX4's would work but the Intel's wouldn't, nor would a POD.

I didn't manage to get around the problem.

I had another board that wouldn't work with an Am5x86, just came up with '??? 100MHz' at POST and hung, however I managed to find a BIOS online which fixed the issue.

The POD's were supposedly a bit iffy for motherboard compatibility back in the day, but its possible that a BIOS update would solve your problem.

Of course finding a BIOS for some of these old 486 boards online can be pretty challenging... if you manage to find one, and your BIOS chip is not a Flash EPROM then I can erase and reprogram your BIOS for you.

On your mobo, is it possible to set the currently installed CPU (POD83) to operate in write-through mode, as opposed to write-back mode?

I'm giving up, I booted into a dos prompt, went to run speedsys it got about halfway through the cpu test and the monitor light went into standby, earlier I had left the machine for 10 minutes at the dos prompt and it was frozen, I cant see it working, shame.