Breaking into a 3B2/310

[Philip A. Gross]

dce at smsc.sony.com (David Elliott) writes:

>We recently purchased a used 3B2/310 to use as a comparison machine for
>our port of SVR4.  The machine has not been used in a while, and it's
>missing a few cables and adapters, but it does come up.  The problem is
>that the default init state is set to 2, and the previous owners have
>no idea what the root password is.  I made some educated guesses, but
>that's futile.

>We are also missing the manuals, so we can't RTFM to find out how to
>force it into single-user mode.

>Can anyone out there help me get this machine to a state where we can
>change the root password?

I assume that you have the full set of UN*X software for the machine.
If so, then proceed as follows:

Power-up the machine, when the 'DIAGNOSTICS' message is displayed on the
console, press the RESET button on the back of the machine.  Whereupon
it eventually gives you a 'SYSTEM FAILURE' error message, ignore this.
Insert the Essential Utilities Diskette #1 which you will find among
the UN*X OS diskettes.  Then type the firware password (usually 'mcp') 
and get the following prompt:

Enter name of program to execute[]:

Enter /unix.
Whereupon, you will see the following displayed:

Possible load devices are:

Option Number	Slot	Name
-----------------------------
0		0	FD5
1		1	HD72

Enter Load Device Option Number [1 (HD72)]:

Here, you should enter 0.
After some time, the system will eventually boot off of the diskette and
present you with information regarding performing a Full Restore, Partial
Restore, Upgrade, etc.

At this point, you can perform a partial restore, which will restore some
of the essential files and configurations of the system, including the
/etc/passwd file.  Another option is to type 'magic mode' at the prompt.
The system will respond 'POOF!' and present you with another prompt
which lists 'shell' as an option.  If you enter 'shell' at the prompt,
the system will then present you with the '#' UN*X prompt.  Remember that
you are booted on the floppy drive and only have a limited set of commands.
For instance, use 'echo *' in place of the non-existant 'ls' command.

In order to edit the /etc/passwd file on the root filesystem of the 3B2, you
will need to mount the root filesystem to the floppy disk by typing
mount /dev/dsk/c1d0s0 $HARD  (BTW, type 'set' to get a listing of your
environment).  At this point you can edit the $HARD/etc/passwd  using the
'ed' editor to delete the password for root.  After you have finished,
unmount the root filesystem by typing 'unmount /dev/dsk/c1d0s0' and then
exit, whereupon you will be returned to the original menu prompt.  From
here, you can 'quit' and then reboot the system.


===============================================================================
Philip A. Gross       The Computer Solution Co., Inc.       Voice: 804-794-3491
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        The opinions expressed here are strictly mine and nobody elses.
        << I haven't heard what I have to say about that yet. >> :-)

-- 
===============================================================================
Philip A. Gross       The Computer Solution Co., Inc.       Voice: 804-794-3491
-------------------------------------------------------------------------------
INTERNET:	pag at tcsc3b2.tcsc.com