Page 1 of 1

How rip or save BIOS from PCs?

Posted: Thu 12 May, 2022 3:15 pm
by davidinark
I've searched the forums but can't find info on this:

How do you rip/save the BIOS from PCs? I have several older computers that I would like to rip the BIOS and create BIN files for use in PCEM, but I don't know how you do it. I found a Universal BIOS Backup tool, but it only runs through Win7-10, which is useless for old hardware.

Thanks for any help!

Re: How rip or save BIOS from PCs?

Posted: Thu 12 May, 2022 9:21 pm
by terub56
To dump my video BIOS I used this method ripsaw8080 posted here:
https://www.vogons.org/viewtopic.php?p=407930#p407930
You can dump a video BIOS image using DEBUG.EXE included with DOS, just run it and enter these commands:

r cs
c000
r cx
8000
n video.rom
w 0
q

The majority of ISA video cards will have a 32kB video ROM -- some earlier ones might only have 16kB, some later PCI/AGP cards might be more than 32kB, so adjust the 8000 (hex) if needed.

Here it's another method to dump Motherboard BIOS by IanB, but I haven't tested it:
https://www.vogons.org/viewtopic.php?p=645332#p645332
I'd like to see a dump of that BIOS and the VGA BIOS as well.
You can do that from the debug prompt, type the following followed by enter on each line:
DEBUG
N BIOS.BIN
M F000:0 FFFF 8000:0
R BX
1
R CX
0
W 8000:0
N VGA.BIN
M C000:0 FFFF 8000:0
W 8000:0
Both of them require DEBUG.EXE utility from MS-DOS.

But unless your hardware is very similar to the hardware emulated in PCem, you won't be able to create the same machine in PCem.

Re: How rip or save BIOS from PCs?

Posted: Fri 13 May, 2022 1:37 pm
by unreal9010
It has to be identical, not just very similar. For example: given the current state of emulated devices by PCem, you cannot use the dumped bios of GA-6BXC, another Gigabyte Slot 1 board, since that board is currently not emulated. Attempting to use it as GA-686BX will likely result in black screen.
In order to be able to use such dumped bios, you need to write or wait for somebody to write the code that would allow emulation of your desired piece of hardware. However, if your dumped bios belongs to a device emulated by PCem then you will be able to use it.

Re: How rip or save BIOS from PCs?

Posted: Sat 19 Nov, 2022 11:21 am
by omarsis81
The best and most reliable way is to use an eprom programmer. That debug.com method may work in early computers and may not get you a reliable dump.

Re: How rip or save BIOS from PCs?

Posted: Tue 22 Nov, 2022 5:27 pm
by UPerschke
Depending on compatibility you may be able to use Flashrom. https://www.flashrom.org