One of the board pictures at TRW is from GigAHerZ who is an active member here, maybe you can PM and ask for a copy of the bios....

You know what! I found that i still have that bios on my desktop! 😁

Thank you !

I've programmed EEPROM chip.
The MOBO gives 'sings of live' 😉
Without RAM I get long - 3 short -long beep (memory or system board error).
Unfortunately, with memory installed, it is 'dead silent' (checked on 3 different RAM modules).
Maybe it is a matter of missing cache chips.... or there is a problem with MOBO itself.

Yes the missing cache could be a problem if BIOS does not accept 0 cache. The jumpers are only for 128k or 256k...
DO you have a Diag card ? It would help...

Horun wrote on 2024-07-01, 00:28:

Yes the missing cache could be a problem if BIOS does not accept 0 cache. The jumpers are only for 128k or 256k...
DO you have a Diag card ? It would help...

I do have a diag card but without the riser I can't use it 🙁
I'll try to populate cache sockets - maybe this is the only problem.

One thing with cache bothers me...
There is bank_1 with DIP28 sockets marked 32kx8 and bank_0 with DIP32 sockets marked 128kx8.
There is no 512kB cache setting in documentation.

This modo can work without cache for sure. i had one in the past.

AlessandroB wrote on 2024-07-01, 08:45:

This modo can work without cache for sure. i had one in the past.

Yup, the problem is not 'missing cache chips' related.
Inserting the cache did not change anything 🙁

It took me a while....
The main problem was a cold solder joint on the 82C802 chip.
I've resoldered all the pins of the above, installed the battery socket and the motherboard is working.
I also flashed the BIOS to the latest english version.
The board is picky about the BIOS chip, it worked on the AT28C010, but when I was trying to update the BIOS it reported an error about the chip being unrecognized.
Even though there was no attempt to flash the bios, a few first bytes in the flash memory were zeroed.
I've mounted Intel P28F010 and it flashes without any problems.
Thanks for the help to all participants.

Great ! Glad you were able to get it running.

Hi, are you able to share the BIOS update utility? I have the BIOS file but can't find any good links to download the Flash utility. Thanks

I'm not sure you even can flash it on board. You may need to get a dedicated programmer for that.

Locutus wrote on 2024-07-01, 08:20:

Horun wrote on 2024-07-01, 00:28:

Yes the missing cache could be a problem if BIOS does not accept 0 cache. The jumpers are only for 128k or 256k...
DO you have a Diag card ? It would help...

I do have a diag card but without the riser I can't use it 🙁
I'll try to populate cache sockets - maybe this is the only problem.

Probably too late to be any use, but I have a suspicion, which needs to be carefully checked against contacts on the board, specifically the first 4 or so in the riser slot, that you can put an 8bit card in the riser slot, but for 16bit and VLB the indexing is off.

Hi to ALL !

BitWrangler wrote on 2024-12-06, 13:59:

Probably too late to be any use, but I have a suspicion, which needs to be carefully checked against contacts on the board, specifically the first 4 or so in the riser slot, that you can put an 8bit card in the riser slot, but for 16bit and VLB the indexing is off.

The mainboard was repaired and was working fine.
"The main problem was a cold solder joint on the 82C802 chip".

GigAHerZ wrote on 2024-12-06, 13:33:

I'm not sure you even can flash it on board. You may need to get a dedicated programmer for that.

YUP - it has a flashrom onboard and BIOS can be flashed 'on board'.
I've flashed it with english BIOS and uploaded 'raw dump' for external programer:
download/file.php?id=196405

Taisho wrote on 2024-12-05, 23:21:

Hi, are you able to share the BIOS update utility? I have the BIOS file but can't find any good links to download the Flash utility. Thanks

Sure, I'll try to do it tonight.

Sorry for the off-topic, but I need help.

I found a similar motherboard but without additional boards/modules.

Is a VRM-module required for all CPUs to run? I have Cyrix Cx486DX2-V66GP (3.3V), but I don't know if it's compatible with this motherboard.

ott wrote on 2025-09-05, 09:14:

Sorry for the off-topic, but I need help.
I found a similar motherboard but without additional boards/modules.
Is a VRM-module required for all CPUs to run? I have Cyrix Cx486DX2-V66GP (3.3V), but I don't know if it's compatible with this motherboard.

Hi.
You will for sure need the VRM module for low voltage CPUs.
But... you can check this MOBO with 5V CPU.
Check out the picture of my board - VRM connector has to be 'jumpered'.

Locutus wrote on 2025-09-05, 10:34:

But... you can check this MOBO with 5V CPU (check out the picture of my board - VRM connector have 'jumpers' installed).

Thank you very much for the clarification! I didn't notice the jumpers right away, but that's great!

It seems easier to find the 5V processor than the IBM's VRM module itself.

Thanks again!

You're welcome, glad I could help.

I have also bios issues with this board.
I allready got it working with 486dx100 processor, until one day I turned machine on and it just showed black screen.
System boots with external video adapter and I am able to get into bios, but when I try to save bios settings system freeses, and only way to get to bios again is take the battery out for few seconds.
What I have tried is... I've resoldered main Ic's, replaced battery, tested processor and memory on other board, tested power supply on other board, tested other bios chip.
So the issue seems to be that system cannot write to bios chip... but why?