VMS/RSX tape backup problem

joe heck trash3 at splab.cas.neu.edu
Tue Mar 15 17:21:11 CST 2005


Yes, Paul, it has the 240 opcode in the right place.  And I remember the 
MSDP tapes being bootable.  But I have no
way of making a copy of it,  unless I mounted it wrong.  EXCHANGE didn't 
recognize it as
DOS-11, but I'll try again.  If that works, then I should be able to 
read it in and write it back out to another tape.
(and make a copy on the hard drive)  Thanks for the insight.

The problem with the BCK files is that they come in as 2064 byte blocks 
from the tape and VMS gets
really upset when I try to write them to the disk.  Haven't figured out 
how to deblock them enough to
get them on to the system.  The interesting part is that I would have 
expected them to be 2048 (512*4)
but there is either a 16 byte header on each block, or each 512 byte 
record has 4 bytes (Integer) in the
front for recordsize (something RMS would have stuck on there).

And finally, yes, the first step for the (6) 800 BPI tapes is to ditto 
them to other tapes at 1600 BPI.


Paul Koning wrote:

>>>>>>            
>>>>>>
>Could you read them as straight streams of blocks, and produce a .TAP
>file from that, which you can then feed to RSX running in an emulator?
>Or write the data back out to another tape at a density that your RSX
>system supports?
>
>That's a DOS format tape -- the 14 byte record is the file label.  If
>it's bootable, then the next block is the boot program.  You could
>read it and see if it looks like PDP11 code.  A boot block would
>typically have either reset (5) or NOP (0240) in the first word.
>
>	  paul
>
>  
>


More information about the cctalk mailing list