BIOS update, EIDE card, or overlay software? (FAQ Hard disk recognition)
#60745 by cheekygeek
Thu Mar 12, 2015 5:50 pm
I have the misfortune of occasionally working on old industrial computers that are used on machines driven by motion cards. So far I have solved every problem, but this one has me flummoxed. The industrial computer is made up of a backplane that holds an ISA half-size SBC (Single Board Computer) that has a VGA output and a PS/2 keyboard output. I'm not sure of the manufacturer of the SBC. All it says on it is "P5/6x86 SBC VER G4" and on the other side "P/N 960560-G4B". It looks just like this one:

The ordinary procedure is to write an Acronis disk image to a new hard drive (using a different machine that holds the Acronis images). The image is for an WINNT 4 (SP 6) OS plus the program & touchscreen drivers that it runs. Put the new hard drive in the old industrial computer, make sure it works with the touchscreen and boots and send it back to the customer. Most problems are bad hard drives and we don't even need the whole computer. But this one described problems that made me think that it had a bad SBC board and so we had the customer send in the whole computer.

We eventually found a used SBC that seemed to confirm that was the problem (we weren't getting any VGA output and now we were). Now we get this:
Award 4.51PG
As you can see, it recognizes the hard drive, but just a blinking cursor after the last line and won't continue into booting.

From research, it seems that the BIOS has a 8.4 GB limitation, but the old hard drive I'm using right now (which boots fine in a "newer" Dell machine) is only a 6GB drive: so that isn't the issue.

I've restored the Acronis image both with and without the MBR record. It boots both ways in the "newer" Dell and the result in the SBC makes no difference. For that matter, when I set the BIOS to look at the floppy first, it doesn't boot from the floppy either. Same blinking cursor after it has detected the primary and checked for other HDs. The floppy buzzes momentarily like it is being accessed but it won't boot from a floppy either.

I'm not sure that the problem is in my BIOS or that a BIOS update is the problem, but I thought I would ask for any words of wisdom. The SBC does not have a CMOS battery, but it keeps the current date, since I set it.

Thanks in advance for any insights!