How rip or save BIOS from PCs?

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davidinark
Posts: 6
Joined: Sun 24 Mar, 2019 7:26 am

How rip or save BIOS from PCs?

Post 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!
terub56
Posts: 34
Joined: Mon 23 Jan, 2017 12:31 pm

Re: How rip or save BIOS from PCs?

Post 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.
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unreal9010
Posts: 82
Joined: Sat 14 Nov, 2020 8:20 pm

Re: How rip or save BIOS from PCs?

Post 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.
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