Previous Thread
Next Thread
Print Thread
Page 1 of 3 1 2 3
Joined: Aug 2002
Posts: 381
Likes: 1
H
Senior Member
OP Offline
Senior Member
H
Joined: Aug 2002
Posts: 381
Likes: 1
I just attempted to Google on how to image BIOSes from (multiple) Pentium 1 boards I have lying around but with a results number in the hundred thousands, and nothing useful (e.g. "How to dump your PS2 BIOS" and the same useless text threads ^10) I came back here with a software question.

All in all, I'm wondering if anyone could steer me to a (DOS/Win32) program that can run on the actual machines.

One such board doesn't seem to have the standard removable BIOS chip - matter of fact I can't even find something that resembles a BIOS. It's a Packard Bell machine (was originally a P166, then overclocked to 200MHz, it now has a P200 (non-MMX) CPU) which I've had since new.

The three or four other i586 BIOSes (which only work in the "proper" boards of course) I have are the standard Award types, whether they're any different to the current MESS version I don't know.

Joined: Dec 2005
Posts: 330
A
AWJ Offline
Senior Member
Offline
Senior Member
A
Joined: Dec 2005
Posts: 330
"awdflash.exe", the DOS-based program for updating Award BIOSes, also has the capability to save the current BIOS from ROM to disk. "amiflash.exe" is the corresponding program for AMI BIOSes.

I don't know if the modern versions of these utilities that you'll easily find by Googling will work with an old i586 motherboard, though--you might have to do some questing to find old versions.

Joined: Oct 2002
Posts: 1,017
M
Senior Member
Offline
Senior Member
M
Joined: Oct 2002
Posts: 1,017
Unless I'm utterly mistaken, shouldn't it be possible to write a short C or C++ program that casts 0x000f0000 into a pointer, reads out the 64k starting at that address and writes it to a file, and then compile it as a 16-bit DOS program?

Joined: Mar 2001
Posts: 16,910
Likes: 56
R
Very Senior Member
Offline
Very Senior Member
R
Joined: Mar 2001
Posts: 16,910
Likes: 56
Most 386+ BIOSes are > 64k and get banked somehow, so that wouldn't work. (If you could get 32-bit flat access the whole thing *might* exist extending down from ffffffff but I reserve the right to be horribly wrong).

Joined: Sep 2004
Posts: 392
Likes: 4
A
Senior Member
Offline
Senior Member
A
Joined: Sep 2004
Posts: 392
Likes: 4
It's actually far worse than that. Most 386+ BIOSes copy themselves into the RAM from 0xe0000-0xfffff (yes, there is RAM there, just generally overlaid by the BIOS image by the memory controller), and then disable the BIOS mapping so that they can dynamically bank in bits and pieces. For example, the POST code is usually run with the default mapping, but then the ACPI tables and extracted and generated in RAM after switching off the ROM mapping.

However, the physical BIOS location should still be accessible. For a 256k BIOS, it will generally be right at the end of 32-bit memory at physical 0xfffc0000. You have to use big real mode or protected mode to get at it.

Joined: Dec 1999
Posts: 1,178
Likes: 2
J
Very Senior Member
Offline
Very Senior Member
J
Joined: Dec 1999
Posts: 1,178
Likes: 2
This won't help for your current problem, but for appropriately old PCs, you can use dumppc.c or dumpat.c from http://cvs.mess.org:6502/cgi-bin/viewcvs.cgi/mess/tools/messroms/

Joined: Aug 2002
Posts: 381
Likes: 1
H
Senior Member
OP Offline
Senior Member
H
Joined: Aug 2002
Posts: 381
Likes: 1
I also have an IBM 486 (based?) machine, but it might have the same problem with the i586 BIOSes. I haven't run it since finding it though - ripped parts out (sound, graphics card) to get the Packard Smell‚Ѣ going better, which has a sucky onboard S3 Virge (S3 Trio is better!).

Another question - With the Pentium range, are they identical processors or are they different in specs and not just clock speed? I have a 120, 150, two 166es and a 200. The 120, 150 and one 166 have the heat sink stuck on the chip itself, along with a stamped clock speed on the side.

Last edited by Heihachi_73; 01/13/07 04:18 PM.
Joined: Mar 2001
Posts: 16,910
Likes: 56
R
Very Senior Member
Offline
Very Senior Member
R
Joined: Mar 2001
Posts: 16,910
Likes: 56
There's 3 different Pentiums - the original 60/66 were on a larger process and ran very hot (for the time). The 90/100/120/133/150/166/200 were a die-shrink that ran cooler (and could be overclocked on a decent motherboard). Third was the Pentium MMX, which came in 166/200/233 speeds and added MMX but was otherwise similar to the previous one.

Last edited by R. Belmont; 01/13/07 11:47 PM.
Joined: Aug 2002
Posts: 381
Likes: 1
H
Senior Member
OP Offline
Senior Member
H
Joined: Aug 2002
Posts: 381
Likes: 1
Unfortunately my old boards can't go faster than 200, and I have three non-working CPUs (I can't test them / they don't boot) - a Pentium 200 MMX, IBM PR200 and a Cyrix (233?). The non-Intel CPUs are possibly dead as they get extremely hot as soon as they power up (changing the voltage and/or clock speed doesn't do anything).

Joined: Dec 2005
Posts: 330
A
AWJ Offline
Senior Member
Offline
Senior Member
A
Joined: Dec 2005
Posts: 330
Quote:
Third was the Pentium MMX, which came in 166/200/233 speeds and added MMX but was otherwise similar to the previous one.


The Pentium MMX also ran at a different voltage than the non-MMX versions, so it didn't work in all motherboards (though that was hardly unusual in the Socket 7 era)

Last edited by AWJ; 01/14/07 09:26 AM.
Page 1 of 3 1 2 3

Link Copied to Clipboard
Who's Online Now
1 members (r09), 19 guests, and 0 robots.
Key: Admin, Global Mod, Mod
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Forum Statistics
Forums9
Topics9,085
Posts119,077
Members5,014
Most Online890
Jan 17th, 2020
Our Sponsor
These forums are sponsored by Superior Solitaire, an ad-free card game collection for macOS and iOS. Download it today!

Superior Solitaire
Forum hosted by www.retrogamesformac.com