[Info-vax] Backup TK50 tapes

[Dennis Boone]

 > dd is about as low level as is possible to get, so if you know the block
 > size, then dd will faithfully read the tape with each block as a stream
 > of bytes. afaics, there's nothing magic about a vms format tape, it's
 > still just a series of blocks on tape.

You continue to fail to get it.  It's not about how "low-level" the
tool is.  The blocks aren't necessarily all the same size.  You may
not _know_ the size, even if they are.  The next guy who has to pick
up your image _probably_ doesn't know.  The size of the blocks matters
in many cases.  If you use dd, you THROW AWAY this information, and
save just a stream of bytes.  Don't use dd to image tapes.  Don't.
Eh eh eh, I see you thinking about doing it anyway.  STOP.  Use a
tool which saves this data.

If you're going to use the image with a simulator, it probably wants
.tap format or similar anyway.  A .tap image preserves the block sizes.
There are plenty of tools for building such images.  Use one.

De