This does eem to be a very rare board.

I recently got my hands on this same board, so far the only issue is a dead RAM chip.
The board has DIP sockets silkscreened around to indicate SIMM banks. I assume these are for SIP modules.

Instead of replacing the faulty 4256 chips I wanted to either add pins to some SIMM\s I have or replace the sockets with SIMM sockets.
I'm new to 286 with NEAT BIOS, it seems it could take 1mb SIMM's in each socket? could it take 4mb for the max of 16mb ?

If I use 70ns would I be able to reduce the wait state to 0 ? or would I need faster

Darrylo wrote on 2024-01-05, 09:36:

This does eem to be a very rare board. […]
Show full quote

This does eem to be a very rare board.

I recently got my hands on this same board, so far the only issue is a dead RAM chip.
The board has DIP sockets silkscreened around to indicate SIMM banks. I assume these are for SIP modules.

Instead of replacing the faulty 4256 chips I wanted to either add pins to some SIMM\s I have or replace the sockets with SIMM sockets.
I'm new to 286 with NEAT BIOS, it seems it could take 1mb SIMM's in each socket? could it take 4mb for the max of 16mb ?

If I use 70ns would I be able to reduce the wait state to 0 ? or would I need faster

Hallo, yes it is. I gave it back to my friend. Would like to have one too. The bios is good but tricky to set right.
1) Yea, the in-line dips are for SIPP and you can install simm sockets, I am 99% sure - it it dits in thr mechanical way.
2) I am not sure of 4x4Mb - I have tested only dipps and 4x256 SIPP
- Most likely you would be able to use only 4x1MB (??) I was not able to try - not enough SIPP modules
3) It depends what frequency is your CPU. At 25Mhz 70ns is too slow. As a rule of thumb try to source good 60ns RAM for your board
4) Important notice - I was not able to run the board with SIPP only! Once I have removed the DIP chips it was beeping "no RAM". I have found one guy on RetroWeb Discord anfd his experience was the same.
Maybe disable this bank in bios before removing the chips could possibly help - not sure if tried. The only combo I have tested was 1MB SIPP + 1MB DIP and no parity.
--
Good luck with your project. Do not hesitate to post here. It is a rare board and our experience could possibly help others.

H.W.Necromancer wrote on 2024-01-17, 15:24:

Hallo, yes it is. I gave it back to my friend. Would like to have one too. The bios is good but tricky to set right. 1) Yea, th […]
Show full quote

Darrylo wrote on 2024-01-05, 09:36:

This does eem to be a very rare board. […]
Show full quote

This does eem to be a very rare board.

I recently got my hands on this same board, so far the only issue is a dead RAM chip.
The board has DIP sockets silkscreened around to indicate SIMM banks. I assume these are for SIP modules.

Instead of replacing the faulty 4256 chips I wanted to either add pins to some SIMM\s I have or replace the sockets with SIMM sockets.
I'm new to 286 with NEAT BIOS, it seems it could take 1mb SIMM's in each socket? could it take 4mb for the max of 16mb ?

If I use 70ns would I be able to reduce the wait state to 0 ? or would I need faster

Hallo, yes it is. I gave it back to my friend. Would like to have one too. The bios is good but tricky to set right.
1) Yea, the in-line dips are for SIPP and you can install simm sockets, I am 99% sure - it it dits in thr mechanical way.
2) I am not sure of 4x4Mb - I have tested only dipps and 4x256 SIPP
- Most likely you would be able to use only 4x1MB (??) I was not able to try - not enough SIPP modules
3) It depends what frequency is your CPU. At 25Mhz 70ns is too slow. As a rule of thumb try to source good 60ns RAM for your board
4) Important notice - I was not able to run the board with SIPP only! Once I have removed the DIP chips it was beeping "no RAM". I have found one guy on RetroWeb Discord anfd his experience was the same.
Maybe disable this bank in bios before removing the chips could possibly help - not sure if tried. The only combo I have tested was 1MB SIPP + 1MB DIP and no parity.
--
Good luck with your project. Do not hesitate to post here. It is a rare board and our experience could possibly help others.

I had the same board but I sold it when its battery leaked. I still have its original user's manual and the box with its serial number. If you could sent me yours' serial number I would be able to tell if it is the same board I sold 😀 The last digit of its serial number is 5.