24 Dec
2005
24 Dec
'05
12:11 p.m.
From: "Miller, Keven" <kevenm at reeltapetransfer.com>
Cc: <cctalk at classiccmp.org>
Sent: Saturday, December 24, 2005 12:25 PM
Subject: PDP-11 9-track tapes
Recently I received 4 tapes from a PDP-11, RSX-11M,
created
with backup (BRU format), that I instantly get media read
errors.
Because of the "older" system, I am suspecting that they may
be 800 bpi tapes.
I am not familiar with PDP, so I can only answer based on my experience.
7-track tapes went out of fashion around 1970 or so. In my first job I
encountered an IBM drive for 7 AND 9 track, and that was in 1969.
800 bpi would be more like it, but you didnt give the make/model of the
drive used, so that's only a guess.
It could very well be a case of too large blocklength; many drives (or
operating systems!) I've seen cannot read blocks larger then 32K. This is
especially a problem for tapes from the oil and geophysical industries.
If nobody else can be of help, you're welcome to send me a tape, so I can
have a look at it
Cheers
Nico (located in Denmark)