[plug] Flash ROMS for Abit Mainbords (BH6)

Bill Kenworthy billk at opera.iinet.net.au
Wed Jan 5 20:45:44 WST 2000

Len, is this a new type of bios setup?- I have only come across boards where
the battery supplies the cmos chip holding user settings and the bios is in a
flash rom (thus "flash.exe").  Sometimes these are in the same package (came
across an older pentium board with this that caught a chenoble virus (from the
symptoms) and it appeared to kill the bios as well as wipe the first few tracks
of the HD! - didnt bother trying  to recover it,  put a new board in!).  In
this case, trying to boot from a floppy is useless without a functioning bios
and trying clear the bios by removing power only removes settings, not rom code
- useless in this case.  Also many if not most cmos batteries I have come
across are lithium these days and should not be charged - i.e., when flat
replace, so I do not envisage flattening them on purpose.  Usually there are
jumpers to disconnect them for this purpose of clearing the cmos.  I presume
from Mike's comments that an isa vesa card on board bios can be pursuaded to
boot a pc - maybe a helpfull fact to know?

Despite my comments above, there are/were some older 386 boards that had a
nicad battery charged from a diode off the power supply.  These tended to fail
before the alkaline batteries that were the alternative in those days so (I
presume) disappeared around the time that the 486 boards appeared.  In any case
these only powered the cmos and flash roms were not common then (cost?)


* if thinking of hot swapping bios chips, you may need to check if shadowing is
swithced on so that the bios is only read at bootup.

Len Bird wrote:

> Michael wrote:
> > -----Original Message-----
> > From: Michael Hunt <Michael.J.Hunt at usa.net>
> > To: plug at linux.org.au <plug at linux.org.au>
> > Date: Tuesday, 4 January 2000 23:51
> > Subject: [plug] Flash ROMS for Abit Mainbords (BH6)
> >
> > >Hi ya all,
> > >
> > >Wanting to get some long overdues work done on my Home PC i decided to
> > >do a flash upgrade of my BIOS in order to sort out some ATA66 issues I
> >

> > If you have access to an old un-accelerated ISA video card, you might
> > be able to recover your BIOS. Remove all cards and drives from your
> > system, except for the ISA video card and the floppy drive. Then try
> > to boot from a system disk (a bootable floppy with only the flash
> > programs and corresponding BIOS binary). If you are able to boot to
> > the floppy, you should be able to recover it.
> >
> > Mike
> I think the safest way to tackle the problem is to get yourself a copy of
> the correct BIOS update, and
> I assume that you know where to get this, then download the FLASH.EXE
> utility from the same
> source to pre-empt any problems there.  You will need to get a humble old
> DOS system diskette,
> and append the BIOS and Flash utility to it.  Try this on its own to see if
> this will overwright the
> corrupted BIOS, otherwise you will have to "kill" the corrupt data by
> somehow flattening the BIOS
> memory.   To do this use say a 100 ohm resistor, the actual value is not all
> that important but DO NOT
> repeat NOT directly short circuit the BIOS battery---as it will not like
> this!!!   Make sure the 5v
> battery is as near flat as possible, restart the computer using the DOS
> system diskette, allow time for
> the BIOS battery to recharge itself from the Power Supply ---- a multimeter
> is usefull here, and
> then run your Flash utility etc.   This works for some systems----but may
> not be the answer for your
> system.  Anyhow you cannot be worse off than you presently are (smirk)
> Cheers and best of luck,
> Len Bird.

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