OK so I just ran CacheChk with my external cache disabled and internal enabled. Why would it not pick up my L1? Also is the "It looks like RAM at megabyte #3 is REALLY slow!" message to do with my external cache?

I tried swapping out all the ram modules and got the same result.

Cheers

I am getting a shockingly bad CPU score in speed sys too

OK so I've removed all the cachechips and still getting the slow RAM at megabyte #3 message.

However, when I enabled the external cache in the bios and rebooted it is now saying I have 512KB installed after post!? (prior it was 256KB, when enabled)

Is turbo enabled? Usually weird low scores are because turbo is disabled... Look for the turbo button header.

Some boards change bus speed, some disable L1 and / or L2 cache or some combination of all with the turbo button.

The turbo headers have nothing attached at the moment. I'll double check the bios, but I am pretty sure having the turbo enabled/disabled has no effect.

Also, I tried disabling the internal cache and the "RAM at megabyte #3 is REALLY slow" cachechk message went away...

Is this motherboard spitting the dummy or is the behaviour of some bad jumper settings somewhere (I can't find the exact manual which doesn't help. Only boards with a very similar but not exact layout)

🤣 love the topic you chose: "Cache woes. Is it Faulty or is it the Motherboard being spastic?"
Are all the ram SIMMS the exact same ? If not could explain the "RAM at megabyte #3 is REALLY slow". Also try cleaning the simm sockets and simm edge contacts with ISO Alc.
You should also try the cache chips again, make sure you inspect each socket and then insert them firmly (press hard after carefully inserting), make sure you put them in correctly.
Before running any tests reset the BIOS to defaults. You have 25nS cache chips which require extra wait states at 33Mhz versus 20nS of many other boards.
Just checked and all of my 386 have 20nS cache chips with 15nS TAGS, even my Asus 386 ISA-386C (first board built and retail sold by Asus) has 20nS cache chips.
If still errors I would double check the BIOS settings as it might have cache speed/wait states set wrong.

Thanks. The ram SIMMS are definitely all the same type (even when I swap them all out for another brand).

I'll give the sockets all a good soaking with ISO Alc.

The 386 cache chips which I was considering using as replacements are 25ns but the onces I removed from the board appear to be 15ns. Will 25's work?

BIOS is pretty minimal re settings. Will have another look over though.

You're super sure on the turbo? Maybe put a spare jumper cap over the turbo connector and boot with that?
Those cachechk speeds are deplorable. It has nothing to do with megabyte 3 in particular.

Thank you good sir!

I put a jumper over the turbo pins and what would you know....cachechk is looking much better!

Now ill add the cache chips back in and see what happens!

OK I reinstalled the cache. I seem to be frequently getting the XMS error at boot. Initially it was loading dos fine, other times it will error out..

If you reboot say 10 times and keep track of the address where it fails, what digits does the address end in? Looks like 4 in both your screenshots. This might be able to tell you which cache chip is bad

Ok so I rebooted 10 times. The 10th time it booted fine. All other times I got the XMS errors with the following addresses (in order)

00166794h x3
001663d4h
00166310h x4
00166190h x2

When it does boot successfully and I run cachechk I get these results:

Horun wrote on 2020-11-26, 02:38:

LOL love the topic you chose: "Cache woes. Is it Faulty or is it the Motherboard being spastic?" Are all the ram SIMMS the exact […]
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🤣 love the topic you chose: "Cache woes. Is it Faulty or is it the Motherboard being spastic?"
Are all the ram SIMMS the exact same ? If not could explain the "RAM at megabyte #3 is REALLY slow". Also try cleaning the simm sockets and simm edge contacts with ISO Alc.
You should also try the cache chips again, make sure you inspect each socket and then insert them firmly (press hard after carefully inserting), make sure you put them in correctly.
Before running any tests reset the BIOS to defaults. You have 25nS cache chips which require extra wait states at 33Mhz versus 20nS of many other boards.
Just checked and all of my 386 have 20nS cache chips with 15nS TAGS, even my Asus 386 ISA-386C (first board built and retail sold by Asus) has 20nS cache chips.
If still errors I would double check the BIOS settings as it might have cache speed/wait states set wrong.

These days on older motherboard i would recommend to use Deoxit D5.. I can imagine that after some time, sockets / contacts/slots having sort of corrosion

So i would recommend to save the bios rom first. Remove old battery, clean the motherboard *eventuelly in isopropa alcohol bath.. and using a tooth brush..
Then wait till the board is dry.. After that apply the deoxit d5 threatment.. And clean the legs of the ram chips / memory chip / isa slots..
After cleaning the board should work better.

You could try swapping the U12 and U24 cache chips and see if that changes anything.

It could be a line form cache or memory losing connectivity, signal is lost sometimes and not others.

If you had a external programmer like a tl866 you could check the cache chips direct and rule them out

treeman wrote on 2020-11-27, 00:27:

It could be a line form cache or memory losing connectivity, signal is lost sometimes and not others.

If you had a external programmer like a tl866 you could check the cache chips direct and rule them out

I was going to suggest that, but I had a similar issue to this where all four chips passed the TL-866 II. I ended up narrowing it down to one of the chips and replacing it.

It’s a pretty clean board to be honest. No signs of oxidation or corrosion. I’ll clean it some more regardless 😒

An external programmer is way out of my league at this point in my retro career. Maybe in a few years...

Does anyone know how to ascertain what KB size those 25 chips will be? There is no point in trying them if I cannot set the jumpers to the correct size settings on the motherboard.

Looks to me like they are 64Kb chips, so you will have 64KB.

I think you should be good till a 25Mhz or 33Mhz FSB with those 25ns chips since the tag chip generally needs to be faster than the rest of the chips.

If you *really* want to try the 64K chips just make sure you have the right tools, between removing 8 chips and inserting 8 chips something is bound to go wrong otherwise...

did you try swapping two of the cache chips as mentioned? it would be interesting to see if you can get the last digit in the failing address to change, that would indicate one of the chips you swapped was bad.