Hi Totalgearhead,

Welcome to Vogons!

This 09/15/97-i430TX-2A59IA29C-00 BIOS-ID identifies this BIOS as for an A-Trend ATC-5000 board. So Progen must have used an A-Trend BIOS for their TX430B board.
This makes sense because these boards are practically identical. Only the location of the SIMM and DIMM slots is different.

https://theretroweb.com/motherboards/s/a-trend-atc-5000#bios
I believe that an ATC-5000 BIOS should work fine on your TX430B, like the latest Ver. 1.08a.

Note that a 0D -> 41 POST code sequence means that the BIOS Bootblock detected a BIOS Checksum Error and entered the BIOS Recovery mode. You should be able to see this Error message when using an ISA Videocard.
Because these Award v4.51PG BIOSes are compressed, the Bootblock first checks the first Mbyte of RAM before it copies itself there to start the decompresses process. The Bootblock then performs a checksum check on the decompression engine and the still compressed Main System module in RAM. If these checks fail, the BIOS will enter Recovery mode.
After the BIOS decompression stage, an additional integrity check is done on the decompressed modules in RAM, before control is passed to them to continue POST. If this additional check fails, the BIOS will enter Recovery mode as well. The BIOS could have become corrupted.

But if you still get the 0D -> 41 POST code sequence with a freshly flashed 1.08a BIOS copy, and you flashed including Bootblock, then there is probably something wrong with your memory system. This can be the RAM sticks, the SIM/DIMM slots, broken motherboard traces of the memory address or datalines, or bad caps in the memory supply.

Hope this helps.
Cheers, Jan

Edit: Expanded the BIOS checksum logic write-up, to make the decisions to enter Recovery mode more clear.

Chkcpu wrote on 2025-10-26, 15:45:

Hi Totalgearhead, […]
Show full quote

Hi Totalgearhead,

Welcome to Vogons!

This 09/15/97-i430TX-2A59IA29C-00 BIOS-ID identifies this BIOS as for an A-Trend ATC-5000 board. So Progen must have used an A-Trend BIOS for their TX430B board.
This makes sense because these boards are practically identical. Only the location of the SIMM and DIMM slots is different.

https://theretroweb.com/motherboards/s/a-trend-atc-5000#bios
I believe that an ATC-5000 BIOS should work fine on your TX430B, like the latest Ver. 1.08a.

Note that a 0D -> 41 POST code sequence means that the BIOS Bootblock detected a BIOS Checksum Error and entered the BIOS Recovery mode. You should be able to see this Error message when using an ISA Videocard.
Because these Award v4.51PG BIOSes are compressed, the Bootblock first checks the first Mbyte of RAM before it decompresses its modules there. If this memory check fails, the BIOS will enter Recovery mode.
Also, if this memory check passes, an additional integrity check is done on the decompressed modules in RAM, before control is passed to them to continue POST. If this additional check fails, the BIOS will enter Recovery mode as well. The BIOS could have become corrupted.

But if you still get the 0D -> 41 POST code sequence with a freshly flashed 1.08a BIOS copy, and you flashed including Bootblock, then there is probably something wrong with your memory system. This can be the RAM sticks, the SIM/DIMM slots, broken motherboard traces of the memory address or datalines, or bad caps in the memory supply.

Hope this helps.
Cheers, Jan

Thank you Jan, I tried that Bios (again) and have been testing random bios files including that one as it has the same string and the 5030 to name a few. This particular BIOS re-test got stuck at the 41->0D still. I have tested and verified and or replaced all the caps in this board. I will get out my ISA video card to see what that shows me then I will check the voltages on the memory slots. I have looked over the board with a microscope and see no damage or missing traces? I have tried both SIMM and DIMM memory and its gives the same result. With No memory it halts before that at C1,C0 i believe. I appreciate the response and will report back. Thanks again.

I have tested the voltages to both types of memory and they are correct. I am still getting the 0D/0C → 41/0D then constant beeps. I will verify the clock crystal and then start looking at the SMC fdc37m672 chip. If anybody has any guidance to troubleshoot the memory side of the board I would appreciate any input thank you.

Totalgearhead wrote on Yesterday, 11:38:

I have tested the voltages to both types of memory and they are correct. I am still getting the 0D/0C → 41/0D then constant beeps. I will verify the clock crystal and then start looking at the SMC fdc37m672 chip. If anybody has any guidance to troubleshoot the memory side of the board I would appreciate any input thank you.

If you have an (E)EPROM programmer, can you make a copy of your present BIOS chip contents and sent it with your reply? So I can check if there is any corruption.

For further troubleshooting, a list of all POST codes from the first C0 to the last 41 would help. Most POST analyzer cards have a “step back” button to view all stored POST codes.
If you can get this POST sequence with the ATC-5000 v1.08a BIOS loaded, then I can compare it with the Bootblock code and see where it goes wrong.

Regards, Jan

Thank you Jan, i have retrieved the codes during boot and working backwards they are: 41,0d,0c,01,c5,0c,c6,c1,00,c0

I have uploaded the BIOS from my chip that you recommended (ATC-5000 latest Ver. 1.08a) and gave the above codes. Thank you for the help, I appreciate it. I'm not at all able to decipher a BIOS or understand whats happening behind the curtain.