24 Nov
2003
24 Nov
'03
3:26 a.m.
Ian,
The message is - to my knowledge - contained in boot blocks of RSX
volumes that are not meant to be bootable. There is a simple routine
instead of the secondary bootstrap that only outputs the string and then
halts. It's kind of a grounding wire to make sure you won't boot off a
tape that contains just user data in place of system files, and hence
might produce unpredictable results. Nevertheless, this is proof that
you managed to read the tape.
You may want to look for a tape that is labelled "Standalone BRU" or
"BRU64K": it should contain a variant of the "Backup / Restore
Utility"
that works independently of the operating system and is bootable on its
own (actually, a specialized RSX system with pre-loaded BRU task). You
boot this tape, unload, then mount the actual data tape (one of those
you tried), and do the actual restore. This is how you would start a
SYSGEN (SYStem GENeration) after receiving a tape kit from Digital.
If you have a lot of time to wait, I might provide a Standalone BRU tape
(1600bpi only, I use a TS05!), but I'm afraid I'll have no time for my
PDP-11 before Christmas. Certainly, other list members can also do so.
But then, where will you copy the contents of the tape if your disk is
not yet connected? - Maybe trying to boot off disk is a better next step?
Regards,
Andreas
der Mouse wrote:
Yes! This is very encouraging.
--
Andreas Freiherr
Vishay Semiconductor GmbH, Heilbronn, Germany
http://www.vishay.com
[...], and the tape drive started to whir! It seeked
back and forth
in tiny and equal increments. Then, the drive stopped and 012710
was displayed, then the @ prompt. I typed g, and got:
*** THIS VOLUME DOES NOT CONTAIN A HARDWARE BOOTABLE SYSTEM ***.
OK, this means (a) the tape boot works, (b) the machine is basically
OK, and (c) the tape connection is OK (now). Progress! Since the "*** THIS VOLUME" ... comes
from the boot loader (it is not
in the bootstrap program...) on tape, we *did* load something from
it.
Not quite. It comes from the boot loader obtained somehow from the
tape interface. We do not know whether the controller got it from ROM
on the controller, from ROM on the drive, or from stuff read off the
tape. My guess would be it's part of the code DMAed into low memory
(from ROM somewhere), not part of something read from the tape, simply
because it makes sense for there to be a complaint in case someone
tries to boot from a totally garbage tape, and this message looks very
much like what I'd expect that complaint to be.
Even though we were able to load the secondary
bootstrap off tape
(which is blocks 0 and/or 1 on tape), we **ALSO** need to have that
code know what we're loading from.
Yes...except that we don't actually know we loaded anything off the
tape (see above).
Either the tape is a "ANSI standard"
tape of some kind (with valid
boot blocks, but no bootable system) or it is a regular bootable
tape, but with a boot block for TM11 controllers...
Or it's a nonbootable tape, and the message came from the ROMed boot
code DMAed into low core.
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse(a)rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B