[Info-vax] Backup TK50 tapes

[John E. Malmberg]

On 2/22/2013 7:45 PM, supervinx wrote:
>
> Hi !
> I'm facing this problem.
> I have a bunch of TK50 original tapes and I want to create tape images, in order
> to save data and use them into simh.

As Hoff has replied to you, that is the hardest way to accomplish what 
you want to do.  Use the logical disk program that he referenced.

Unless you want to be the first to boot simh from a tape image instead 
of a disk image like everyone else does.

> I have only a functional TK70 unit (VAX 4000/300), no SCSI units to
> connect elsewhere and use tapecopy/tapedd.

That is good enough to read the TK50 tapes.

> Many tapes are boot tapes, so I want to preserve their structure
> ("normal tapes" containing only savesets are easily read and copied),
> creating a bootable image.

If you back them up to a logical disk, that disk is bootable by SimH.

A disk image with VMS installed can be repaired to be bootable with the 
writeboot utility.  No need to preserve the structure.

If you really want to make bootable tape images, use the logical tape 
program from the same place that the logical disk program is downloaded.

And then you can hack a procedure based on the command procedure to 
build standalone backup on tape, which is present on VAX systems.  I 
think it is in SYS$UPDATE, but since I have not used it since 
info-servers and hobbyist clustering became available, so it has been 
well over a decade.

 > 2) How can I create if not a bit-by-bit copy a functionally
 > equivalent one ?

For your stated task, you do not need to, unless you really want to 
learn a lot about how to create bootable tapes, which is something that 
just about everyone on this list stopped doing well over a decade ago.

 > Will COPY/LOG from the TK70 to a simh virtual tape (I have a cluster 
 > handy) do this ?

I do not think so.  As I and others have been making a point of never 
ever booting from tape unless there is no other alternative, it is not 
likely that you will find an active participant in any VMS forum that 
knows a simple way to do this.  The only way that VMS supported end 
users creating a bootable tape is with the procedure to create the 
standalone backup utility on tape.

With a cluster, you can network boot SimH as a satellite and load the 
software on to its logical disks and then boot it standalone if you wish 
and do an install.

Or as previously pointed out by Hoff, you can just copy over logical 
disk images from the VAX via a TCP/IP connection to the SimH host and 
have SimH use them.

What we do not understand is why you think you need to preserve these 
tapes as tape images, when disk images will provide the same functionality.

Regards,
-John
wb8tyw at qsl.network
Personal Opinion Only