[rescue] AViiON 530, DG/UX 5.4R3.10 - reset root password?

[Ray Crane]

 I've just successfuly booted a DG aviion 530 that I've had sitting
 in my basement for a couple months after having rescued it from work.

 I wasn't able to get it to initialize video on the Mitsubishi monitor
 I hooked it up to, and the only keyboard I had to hook up to it was a
 standard PC-AT keyboard, so I opted to go with the serial console
 using the laptop and minicom. 

 According to the boot messages its a dual-33Mhz with 40M RAM. 

 After some nice fsck'ing and complaints about mountpoints it couldn't
 mount, I seem to be sitting at a friendly console login prompt.

 Additionaly, I thought I saw a message scroll by mentioning that the
 root partition was full, and various instances of sendmail are certainly
 unhappy about SOMETHING and are thus spewing to the console, which I 
 suspect is caused by the no space on the root partition but I'm not
 posative because the complaint is over 80 characters and it doesn't
 wrap. 

 At this point, I'd like to get to the POINT of this email..... I have
 no idea what accounts are on this machine or what their passwords 
 (including root) would be. So I'm looking for ideas on how to get into
 it. 

 The general trick for wiping out the root password on Unix variants
 always seems to be to boot to floppy/cdrom/singleuser (assuming singleuser
 doesn't ask for the root pw) then temporarily mount the hard drive and
 overwrite root's crypted password, save, umount, reboot. I've never had
 to do such a procedure on a machine of this vintage, though, and I've
 never touched *any* DG/UX machine to my recollection. 

 Is such a procedure the recommended plan of attack here? If so, what 
 are the actual details? If not, what's a guy to do? I'm not totally 
 averse to reloading the OS from scratch, and it so happens that I have 
 a copy of DG/UX on CD (still shrinkwrapped and never opened) but the 
 bad news is that this machine has no CDROM drive, only tape. 

 Any information/hints/clues/pointers/etc are much appreciated.

--
Ray Crane <rcrane at germanisches.com>