You should provide more information up front.
I assume it's this board here:
https://www.ultimateretro.net/en/motherboards/7963#downloads

Screenshot from the manual - maybe someone can figure it out, too early in the day for me:

Can you post pictures of your board? That's always helpful when trying to figure out issues on hardware that has jumpers and lots of socketed/changeable ICs.

Doornkaat wrote on 2022-03-23, 08:55:

Can you post pictures of your board? That's always helpful when trying to figure out issues on hardware that has jumpers and lots of socketed/changeable ICs.

There's a good generic one at the page i linked to but yes - picture of the actual patient couldn't hurt!

Cuttoon wrote on 2022-03-23, 09:08:

Doornkaat wrote on 2022-03-23, 08:55:

Can you post pictures of your board? That's always helpful when trying to figure out issues on hardware that has jumpers and lots of socketed/changeable ICs.

There's a good generic one at the page i linked to but yes - picture of the actual patient couldn't hurt!

I'm asking for a picture so the configuration on the OP's board can be confirmed and to see wether there are any obvious defects. Visual inspection is the first step of hardware troubleshooting, isn't it?

Doornkaat wrote on 2022-03-23, 09:29:

Cuttoon wrote on 2022-03-23, 09:08:

Doornkaat wrote on 2022-03-23, 08:55:

Can you post pictures of your board? That's always helpful when trying to figure out issues on hardware that has jumpers and lots of socketed/changeable ICs.

There's a good generic one at the page i linked to but yes - picture of the actual patient couldn't hurt!

I'm asking for a picture so the configuration on the OP's board can be confirmed and to see wether there are any obvious defects. Visual inspection is the first step of hardware troubleshooting, isn't it?

indeed!

Long shots while the pics may be on the way.

Some boards require specific SRAM layouts and properties. Although they are electrically compatible they may be different on the inside and the board just refused one kind.

Could you try with only the 5 256 chips?
That working, may indicate some incompatibility and the system may dislike the combined 256/257 chips.
Or swap these chips one by one too see if one is broken.

Also try to insert some wait states, maybe that's the issue of things seem unstable. Some faster Socket 3 CPUs push the 15ns chips to the limits or slightly over.
There's also a slight chance order chips are just printed with the 15ns rating but can't really go past 20 it even 25 (really nasty but it happened)

pic of existing cache

andy120 wrote on 2022-03-23, 21:10:

pic of existing cache

Trying out all combinations of the jumpers is weird.
So you have 8 times 32Kx8 and one time 32kx8 for tag ram.
It seems that the winbond chips were added to board later. Are they fake chips?

they all have traces. if i use the 512's i have and know are good, i should install 4 right?

Try the 128K setting first with 4 modules in the 32 pin sockets plus tag.
What happens?

That worked, but only write through, totally fails write on back. Im running a amd 5x86-133 currently. Is write back essential?

Okay. Please run SpeedSys 4.78, generate a .PCX picture afterwards inside the program, convert it to .PNG and post it here please.
I'd like to see the cache chart right bottom of the screen/picture.

I suggest to deal with write back later.
Does it still work when you swap the 4 modules by the unused modules?

it appears there are too many stuffed 256's than i have replacements, so it has 4 new 512's in.

Well, I don't see an active L2 cache at all in that chart.

shizer. is that why write back doesnt work.

edit
just seen the boot screen says 256k cache with 512's in and jumpers for 512. i assume that means fake cache. also didnt have 32-bit enabled

andy120 wrote on 2022-03-24, 20:44:

shizer. is that why write back doesnt work.

edit
just seen the boot screen says 256k cache with 512's in and jumpers for 512. i assume that means fake cache. also didnt have 32-bit enabled

oh boy.
you wrote
" ....
i also have enough UM61256-15's to fill all the sockets and have some UM61512-15's
...."
Um61512 means 64kx8, so you cannot get 512kB cache, it would be only 256kBytes either.

Are you sure you set the jumpers correctly for any of the settings?

EDIT:
I checked your picture (where you had 8 times 32kx8 data and 1 one time 32kx8 for tag)
You have there JP5 1-2, JP6 1-2, JP7 Open

That setting is NOT existing, fits to nothing.

More EDIT:
Sorry JP5 is 2-3. So the jumper in the picture were correct, I apologize. My eyes are bad

ahh, got you. so i have the second line. most of my 256's are stuffed.

That looks good now! 256kb L2 cache are there, you can only get more with 4 times 128x8, but as you don't have those, keep it as it is now.

What was weird before that without L2 cache you had a speedsys value of a DX2-50. L2 cache is definitely important 😁

Now you have your cache enabled, but you still do not know what is wrong with your other modules.

Note that you have very bad cache / dram timing. This leads to a poor performance.