vacatedboat wrote on 2023-03-10, 06:37:

I have the .bin file but where can i put it? Its not allowed. I tried it in zip folder but also not possible.
I did however try to rom dump it to the retroweb discord server. Its the one with my user name vacatedboat
Hope it works. Thanks

Hi vacatedboat,

Thanks fort he BIOS file. I got it from The Retro Web Discord server okay.

I’ve checked this 12/19/95 MB500N BIOS and it is a valid BIOS for UMC I/O, so it is a correct BIOS for your board afterall.
I ran your BIOS in 86Box and it worked fine. This is what I got on the boot screens:

In the bottom of the 86Box window, you see the POST codes and the FF code (POST complete and loading bootsector from disk) after code 63.
So I believe your BIOS is okay and the cause of the hang must be elsewhere.

Note1: The “Updating ESCD … Success” line is only displayed on the first boot or after a PnP change.
Note2: The emulated MB500N machine in 86Box is made for SMC I/O and normally uses the 031396s BIOS, that’s why you see a Parallel port adres of 278 instead of the 378 as set in this UMC I/O BIOS.

The 12/19/95 and 02/13/96 BIOSes, do not have a PCI device listing on the second boot screen.
But the later 06/13/96 BIOS does:

This latest 06/13/96 Ver. (60613) BIOS from https://theretroweb.com/motherboards/s/pcpart … 12-32#downloads is for UMC I/O, so okay for your board.
If you can try this BIOS, it will be interesting to see if you get the PCI device listing. This will tell me if the hang occurs before or after displaying this listing.

Jan

Have you tried disabling all 'non-essentials' in the bios ? In cases like this after checking jumpers/ram/cache/RTC(if present)/bios and still get no result , i disable everything i can in the bios : fdd and fdd controller , serial , parallel , ide controller , cache / cpu cache / usb / sound / lan / modem / gameport ( if present ) and if it works , i enable them one by one to see where is the failure .

Well it worked. I used the 60613 - 6-13-96 one. I got the same image as you did and it then proceeded to boot from floppy. I then hooked up a sd2ide drive and it even booted to a dos prompt also.
I then re tried the edo ram stick and they worked fine in bank 0 previously not. So good to get a result.
Im now thinking of giving the coast stick another go to see if its detected.

Im not sure who the previous owner was but when i first got it and started setting jumpers the bios was set in 12v not 5v. I put it into 5v but think back maybe someone tried updating the bios but put one on that was not quite right. Will never know.
Thanks to all who gave help and feedback 🙏

Great to hear it works now and that the 60613 BIOS did the trick! 😀

Cheers, Jan