I've never seen bad ATC boards. Maybe they've done some but I never heared of them then. Looking at your board, I can see two UMC chips that should be the sram chips for the cache.

Prehaps there's something wrong with the cache configuration

Deksor wrote:

Prehaps there's something wrong with the cache configuration

How would I reconfigure that?

If you don't pull the mobo tag and don't insert the COAST stick, how much cache does the system report? It's not fake if it reports 256K.

With tag installed and no COAST, it reports 256k... but companies famously faked that in the past.

Tyrantulas wrote:

With tag installed and no COAST, it reports 256k... but companies famously faked that in the past.

That's why you used CHKCACHE, right? 😉

Sure companies faked cache, but as far as I know, ATrend didn't do this and in the photo I can see two UMC chips that looks like regular SRAM chips. Usually they did show "Write-Back" on them and that was all.

Take a look at the manual (I've found this http://www.elhvb.com/mboards/a-trend/manuals/index.html), maybe some jumpers are set incorrectly ?

The COAST has 32k x 8 tag ram which is plenty for 512KB cache. You should pull out the onboard tag when the COAST is inserted.
What's the label of JP1 on the COAST? Perhaps you need to toggle the jumper cap in order to make things work.

I had a very similar motherboard and I always thought that it was normal that the coast module replaces any on board cache and they do not work at same time. That is why I got 512Kb coast module to begin with.

Baoran wrote:

I had a very similar motherboard and I always thought that it was normal that the coast module replaces any on board cache and they do not work at same time. That is why I got 512Kb coast module to begin with.

It's tricky to get COAST work along with onboard cache without a clear manual. We may have to inspect the features of the board and the stick:

1, board has removeable tag ram? - yes in OP's case
2, size of onboard tag? - can't tell
3, onboard jumpers that configure cache size? - seems not
4, stick has tag ram? - yes
5, size of stick tag? - 32k x 8, enough for 512KB cache
6, stick has jumper? - yes, but can't read the label

lazibayer wrote:

Baoran wrote:

6, stick has jumper? - yes, but can't read the label

Th jumper is marked "linear" and "interleaved" modes.

interleaved is the default operation mode. Linear causes the machine to crash the second it displays the system summary after the main bios screen... it doesn't even fill out the fields... just draws the ASCII frame and then hard locks.

Here are some closeups for part numbers:

Motherboard cache + cache module -

Motherboard TAG chip -

Thanks again!

This confirms what I said, the two UMC chips doesn't look anywhere close to fake cache chips and puting a real tag ram would be pointless if they faked the cache. There's probably something wrong somewhere, but the board doesn't have fake cache for sure

Tyrantulas wrote:

Th jumper is marked "linear" and "interleaved" modes.

interleaved is the default operation mode. Linear causes the machine to crash the second it displays the system summary after the main bios screen... it doesn't even fill out the fields... just draws the ASCII frame and then hard locks.

It should be set to interleaved mode. Have you verified the onboard cache with CHKCACHE, without COAST being inserted?

Onboard cache, with TAG in:

This machine appears to have both L1 and L2 cache.
L1 cache is 8kb
L2 cache is 256kb

Onboard cache, with TAG out:

This machine seem to have one cache?!
?! is 8kb

COAST, with TAG in:

This machine appears to have both L1 and L2 cache.
L1 cache is 8kb
L2 cache is 256kb

COAST, with TAG out:

This machine appears to have both L1 and L2 cache.
L1 cache is 8kb
L2 cache is 256kb

My second COAST module just arrived in the mail... it's identical in design to the first unit, and gives identical results in testing 🙁

the manual says it should work if you remove the onboard tag chip first; the manual speaks of kit-256 coast module - is that the one you utilise? if possible try putting the onboard tag in place of the one on the module?

I can't find the elusive KIT-256, so I've been trying other should be compatible units.

Tyrantulas wrote:

My second COAST module just arrived in the mail... it's identical in design to the first unit, and gives identical results in testing 🙁

Well your onboard cache is definitely real. The board might just doesn't like that COAST... Why don't you try another design?
Your onboard tag is 16k x 8 and sufficient for 512KB cache; so you could try a COAST without on-stick tag.

I'll keep checking on one and see what I can find.