How many FPM sticks are you installing? If you are just using a single stick of 32 MB for testing, set L2 timing to 2-1-1-1, DRAM read/write to 0/0. Set L2 to write-back and Alt Bit to 7+1.

Some Am5x86-133 chips need 3.6 V to run well at 160 MHz. You might need to perform the VRM mod, which is also detailed in the Biostar Manual.

What is the part number listed on your FPM RAM IC's?

I'm using one 32MB stick [IC pic attached, VG2617400DJ]. Changed bios settings acording to your sugestions - no change, pc boots only once. Should i try with even lower L2 timings?

Why is it only booting once? No matter how long i'am browsing in bios - it works, one minute, 15 minutes - it works for as long as i restart the PC.

Hmm, AMD 586 are fairly cheap, think it's easier to just buy another one than VRM mod.

BTW: is it normal that when i change to 160, the cpu is described as P90-S instead P75 [pic attached]

You could try 3-1-1-1 for L2 and 1ws for RAM Read and 0ws for RAM Write.

That memory module is interesting in that the spec sheet says that it can run at, both, 3.3 V and 5.0 V. I haven't come across this before.

P90-S instead of P75 is the expected behaviour for 160 MHz operation.

I do not understand why it is working for only one minute, but it may have something to do with the RTC battery being nearly depleted.

If you run the chip at 133 MHz at 2-1-1-1 and 0/0ws, can you load windows and play games?

Tried even lower L2, no change. PC boots once, i can spend unlimited time in bios, and after reboot - no screen. This is just weird.

So...

With 2-1-1-1, 0ws read/write, L2 WT (picture attached), I get this results:

@133, 32MB FPM

• GLquake: 16,9
  Quake DOS: 13,6
  Quake WIN: 13,3

@133, 128MB FPM

• GLquake: 16,5
  Quake DOS: 13,6
  Quake WIN: 12,6

@133, 64MB FPM

• GLquake: 16,0
  Quake DOS: 13,5
  Quake WIN: 13,3

Looks like 32MB works best in my setup. PC runs stable, no blue screens, etc.

Think i have to accept the fact that my Am5x86 just won't go past 133.

Your results are worse with more memory because you are exceeding the cacheable limit of 256K.

If you are going to stick with 32 MB of RAM, set L2 to Wr-Back and Alt Bit to 7+1. You should see some minor improvement.

What graphics card are you using?

The VRM mod is easy to do for 3.6V operation. You can also try your luck with another Am5x86. These CPUs are everywhere.

I'm using S3 Virge 4MB + 3DFX. The results are pretty decent i think. Probably will stick with 128MB, 3d games are not my priority.

Only two problems are left on my list:

- Windows hangs when i try to restart it. Sometimes after I simply try to close windows it hangs too with black screen.

- Quake with PS2 mouse hangs, when COM mouse is used it works fine. In windows ps2 mouse works fine too.

Other than that, pc works great.

Best to stick with 32 MB in WB L2 mode. It is the most optimal.

Not sure about your other issues. You are using a very early revision of the UMC 8881 chipset. I would try a different Am5x86 CPU.

Just spend few days binge-playing Command and Conquer on my build. Works great, very happy with this setup.

So again - thanks for the help guys !!! this forum rocks 😀