Debug and the ROM BIOS password
Daniel Murphy
Can I use DEBUG to find the ROM BIOS password for a 486 with
AMI BIOS? If not, then what other utilities can I use?
Also, what is the syntax for the debug search command to look
through ALL of memory (not just certain areas) and dump it to a file.
Thanks for the help.
Urban Domeij
boot at all until the password is given. However, there are two
ways (usually) to bypass password.
One is to remove the battery and wait long enough for the cap to
lose power, the other (simpler) method is to use the jumper that
is provided for the purpose. If you don't have the manual for the
motherboard, you can probably find it on the manufacturer's site.
Shorting the right jumper will reset the setup and you may again
boot the machine without a password.
Good luck
Urban
Jon Visick
> Can I use DEBUG to find the ROM BIOS password for a 486 with
> AMI BIOS? If not, then what other utilities can I use?
Easiest solution here is just to remove the battery, wait several
minutes and then replace it; CMOS will "forget" the password and you can
start over.
Charles Dye
On 19 Oct 1997 17:39:11 GMT, Urban Domeij
<marlin...@rocketmail.com> wrote:
>"Daniel Murphy" <danm...@worldnet.att.net> writes:
>>
>> Can I use DEBUG to find the ROM BIOS password for a 486 with
>> AMI BIOS? If not, then what other utilities can I use?
>>
>> Also, what is the syntax for the debug search command to look
>> through ALL of memory (not just certain areas) and dump it to a file.
>You probably cannot use debug.. as you cannot get the machine to
>boot at all until the password is given. However, there are two
>ways (usually) to bypass password.
Another problem is that AMI encrypts their passwords. The password
is stored in locations 37h through 3Dh in CMOS RAM (*not* in the CPU
address space) but don't expect to learn anything by looking at it.
Bit 6, or bits 6 and 7, of CMOS byte 34h control what exactly the
password is used for. In older AMIBIOS machines, clearing both bits
would disable the password.
lacarter
On 19 Oct 1997, Daniel Murphy wrote:
> Date: 19 Oct 1997 02:41:26 GMT
> From: Daniel Murphy <danm...@worldnet.att.net>
> Newsgroups: comp.os.msdos.misc
> Subject: Debug and the ROM BIOS password
>
>
> Can I use DEBUG to find the ROM BIOS password for a 486 with
> AMI BIOS? If not, then what other utilities can I use?
>
> Also, what is the syntax for the debug search command to look
> through ALL of memory (not just certain areas) and dump it to a file.
>
> Thanks for the help.
>
>
Or you could just open up the computer take the batter out and pop it back
in. You might lose other settings as well. But at least you will be able
to get back into your CMOS.
Toodles!
lacarter
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