You might try getting a couple of those "cans of air" used to blow dust out of computers, and spray it until it's blowing quite cold, then aim the blast of cold freon or whatever onto suspect parts. If it alters the behavior, it's likely the cause.

If it runs fine at 133 then try it 160 OC'd with Cache disabled and see what happens....

What Mobo ?

Zerthimon wrote on 2023-03-12, 15:41:

What Mobo ?

AMD 5x86 133Mhz CPU running at 160Mhz (3.3V)
Lucky Star LS-486E motherboard, 256KB L2, new cr2032 CMOS battery
32MB EDO 60ns RAM (4x8)
ATi 3D Rage II PCI Video Card

Horun wrote on 2023-03-12, 15:39:

If it runs fine at 133 then try it 160 OC'd with Cache disabled and see what happens....

The L2 is another interesting subject. I have a thread on this but in short with the L2 enabled no matter what the system will crash. Not just win95 but even low level dos things off a boot disk. Once i disabled L2 nothing ever crashes other than what i said above.

I know the screen shot i gave shows 256k L2 enabled but its an older screen shot. I don't have it enabled now. And even if I go into the Bios and enabled the L2 it never shows up anymore. So I'm guessing i have a bad SRAM chip, and i'm waiting for more to arrive.

The "bad" L2 is still in the system, just disabled in the bios.

Some LS-486E revisions are known to have problems with EDO RAM. Rev C2 works well with EDO, though. What revision is yours?

Zerthimon wrote on 2023-03-12, 16:25:

Some LS-486E revisions are known to have problems with EDO RAM. Rev C2 works well with EDO, though. What revision is yours?

I have 4x8 FPM MEMORY PARITY 60NS SIMM 72-PIN 5V 2X36. And you're correct, i get a black screen with EDO memory. So FPM only for this board.

xbit wrote on 2023-03-12, 17:15:

Zerthimon wrote on 2023-03-12, 16:25:

Some LS-486E revisions are known to have problems with EDO RAM. Rev C2 works well with EDO, though. What revision is yours?

I have 4x8 FPM MEMORY PARITY 60NS SIMM 72-PIN 5V 2X36. And you're correct, i get a black screen with EDO memory. So FPM only for this board.

I did run memtest86+ v4.10 for a few passes with no issues when i first got 'em.

Crazy, my first test was to remove the overclock from 160 back to 130Hmz. When i do this win95 crashes warm or cold 😀

How fast are your cache modules, how many do you have, (8 or 4) and how fast is your TAG ram?

Disruptor wrote on 2023-03-12, 20:22:

How fast are your cache modules, how many do you have, (8 or 4) and how fast is your TAG ram?

4 15ns cache modules and 15ns tag ram (i think, i see a -15). Also attached is manual settings. I'm new to cache settings and tag ram. I never messed with it back in my 486-25 days.

Trying to make a long story short, when i first got the PC i could see that the bios and system could see the 256k L2. But my system was crashing a ton, even from a dos boot disk. I disabled L2 in the bios and it stopped crashing. Now if I enable it again for more testing, it doesn't show.

Ok, 256 kB SRAM in a single bank. That very likely won't give the fastest timings (2-1-1-1) at 40 MHz FSB.

I may have figured out the strange cold/warm issue that i started the tread with. I changed the jumper for the bus overclock. I can't really find documentation on this but i think PCI divider was set to 1:2/3. That said, its now set to 1:1 with the CPU still overclocked to 160. If i try any other combo it goes back to crashing.

The system still can't see the L2 any longer, but i think that's another topic.

Disruptor wrote on 2023-03-12, 22:06:

Ok, 256 kB SRAM in a single bank. That very likely won't give the fastest timings (2-1-1-1) at 40 MHz FSB.

Thank you.
Odd thing is, its not even showing up when booting or after. Could the timing settings be why? or will it just hit the overall performance ?

xbit wrote on 2023-03-12, 22:18:

Disruptor wrote on 2023-03-12, 22:06:

Ok, 256 kB SRAM in a single bank. That very likely won't give the fastest timings (2-1-1-1) at 40 MHz FSB.

Thank you.
Odd thing is, its not even showing up when booting or after. Could the timing settings be why? or will it just hit the overall performance ?

Not sure if this is helpful:

xbit wrote on 2023-03-12, 22:24:

xbit wrote on 2023-03-12, 22:18:

Disruptor wrote on 2023-03-12, 22:06:

Ok, 256 kB SRAM in a single bank. That very likely won't give the fastest timings (2-1-1-1) at 40 MHz FSB.

Thank you.
Odd thing is, its not even showing up when booting or after. Could the timing settings be why? or will it just hit the overall performance ?

Not sure if this is helpful:

Yes, this auto config seems to be wrong, it sets things for a 33MHz bus. you see CLK/4 for ISA. While ISA BUS 10MHz is most likely fine.
2-1-1-1 cache read and 2T cache write most likely is not working.

You can try 3-1-1-1 / 2T, 3-1-1-1 /3T, 2-2-2-2/2T or something ....

EDIT: Try cache write 3T, cache burst read 2T, cache read 3T. So first check if it works, optimisation can be done later 😁