Intel486dx33 wrote:

I have some CPU that I need configuration question to. […]
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I have some CPU that I need configuration question to.

1) Intel 486dx4-100
Is it P24D capable ?
Is it Write-back or Write-thru ?

P24D refers to the 486DX2 CPU that has a L1 write back cache scheme.
However, in the case of the Intel 486DX4-100, it depends. You will have to look at the markings on the CPU to determine that.
If you see a &E, then it's the standard L1 write thru cache model. If you see &EW, then it's the L1 write back cache model.
Or, just search on the internet for the model number printed on the CPU to determine what the L1 cache scheme of the CPU is.

Intel486dx33 wrote:

2) AMD 5x86dx-133-P75
Is it P24D capable ?
Is it Write-back or Write-thru ?

The AMD 5x86-133 supports both L1 cache write thru or write back (on later motherboards, that specifically supports it, it can be selected via a jumper on the motherboard and/or in the CMOS setup).
It was specifically designed like that to cater for motherboards that didn't perhaps fully support L1 write back cache CPU's.

Thanks.

I think it's been confirmed that the &EW DX4 chips support both write back and write through modes. There is a pin that controls it.

Anonymous Coward wrote:

I think it's been confirmed that the &EW DX4 chips support both write back and write through modes. There is a pin that controls it.

Yes, that also makes sense, since all L1 write back cache CPU's should also be able to support L1 write thru cache
The AMD 5x86 supported both cache schemes from the start.