Real tape drive densities
cclist at sydex.com
Mon Feb 15 00:37:37 CST 2016
On 02/14/2016 06:13 PM, Jay Jaeger wrote:
> Maybe some yahoo decided to write over the first file of that SVR4 tape
> at higher density so as not to clobber the files after it. Smart, so as
> not to clobber the other stuff, but crazy. Or it may have been just a
> case of writing that first file, with no double-EOF EOT on it.
> Or maybe someone wrote the first file and then went "OH SH*T that was a
> DISTRO TAPE wasn't it..." ;)
> Anyway, I doubt AT&T would have written the tape that way intentionally.
Well, the tape bears an AT&T label. The tape itself comes from UCB at
about the same time that "ernie" was in use, so VAX or PDP11. It could
be a copy of an AT&T distro tape with the duplicate label attached.
It's a 2,222,000 byte cpio file that starts out with:
# THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T
# The copyright notice above does not evidence any
# actual or intended publication of such source code.
#ident "@(#)mk::mk 1.10"
# Shell script for rebuilding the UNIX System
trap "exit 1" 1 2 3 15
if [ "$ROOT" = "" ]
PATH=/bin:/etc:/usr/bin; export PATH
That's the 6250 GCR file; the 1600 PE file that follows is a 37,432,320
byte cpio file that starts out in exactly the same way. The 2MB file
was probably an "osh*t" file as it terminates prematurely at
I read it on my Fuji 2444 (Pertec interface). None of my SCSI drives
could handle the mixed density.
How many "smart" drives can handle multiple load points? Before the day
of autothreading drives, it was convenient to have a "universal
deadstart" tape to carry along, with various operating systems on it.
Just keep hitting the "load" button until you get to the one you want,
then push the button.
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