VAX-11/730 %BOOT-F-Unexpected Machine Check

Peter Coghlan cctalk at
Mon Jun 8 10:58:07 CDT 2015

Mark J. Blair wrote:
> Since I can't seem to boot up my R80 or my other RL02 pack (labeled
> "VMS53RL02SYS" on top) yet, I've been trying to bring up the VMS 5.3
> Standalone Backup tape images I found there. No luck so far. I have
> never run a VMS Standalone Backup environment before, but I am blindly
> hoping that it will be a small VMS environment that will let me try to
> mount filesystems from my hard drives and see what, if anything, is on
> them. I would greatly appreciate any clues here, because I'm in unknown
> waters.

Standalone backup is a very small VMS environment.  You get a "$" prompt and
the only command which it accepts is "BACKUP".  You don't get to mount anything
as BACKUP will perform any mounting needed itself.  I'm not sure but it is
also possible that only BACKUP /IMAGE works.

The typical way to do a fresh VMS install onto a new disk is to boot standalone
backup (from a tape or another disk) and then use it to restore the "B" saveset
of the VMS distribution onto the target disk.  Then boot the target disk and
answer the questions.

If you manage to get standalone backup running and want to try reading existing
filesystems or distribution media without risking overwriting data you want to
keep, you could try something like:

$ BACKUP /IMAGE /LOG device: NLA0:

With any luck, this should back up the files on "device" to the null device
and list the filenames as it does it.  If it complains, try this:


but that variation probably won't work for distribution media as that will
be provied in saveset form and you can't have a saveset as both input and

Peter Coghlan.

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