[Info-vax] Backup TK50 tapes

[Bob Koehler]

In article <kgclpg$d3h$1 at speranza.aioe.org>, supervinx <nessuno at libero.it> writes:
> 
> Well, let's try to be minimal.
> My goal was to create a physical image of the tapes so, if they will
> "die" (everything has an end, only a sausage has two ;) ) I'll be
> able to recreate them.
> Usually I use a SCSI tape interface, and used tapecopy/tapedd.

   dd and "physical" are the wrong ideas.  These are ANSI/ASCII
   labeled tapes which VMS considers native Files-11 tape structure.

   Mounting these as labeled tapes and using COPY will give you a
   working copy of the tapes.  On real hardware, you could do this
   tape to tape if you had two tape drives, and the output tape would
   be just as bootable as the input tape.

   To use dd, you would have to know the actual record blocking for
   each file.  You would have to dd the tape label, file label, file,
   and end of file label for each file.  (The tape label contains the
   first file lable).  But blocking and such is stored in the tape 
   labels, so just let VMS worry about it.

   Some UNIX have limited ability to deal with these tapes, using the
   ltf utility.  I would not trust it in this case.

   As far as installing VMS on SIMH using such tapes, I'm not sure
   anyone has put tape booting code into any of SIMH's simulated VAX
   consoles.  But if they did, and you made SIMH compatable simulated
   tape files, it should work.