| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1155.1 | Will these help? | SEDSWS::SIAREY | | Mon Mar 17 1997 04:25 | 12 |
| Hi,
I can offer you a paper copy of "TC11 DECtape system manual - DEC-11-HTCB-D"
or "TC11 DECtape system engineer drawings".
Will either (or both) of these help, if so send me a mail with details
of where to send them in the infernal post, SEDSWS::SIAREY.
Regards,
Colin S.
(ps. I am in the UK so they may take awhile to reach you).
|
| 1155.2 | | HELIX::WELLCOME | Steve Wellcome SHR3-1/C22 Pole A22 | Mon Mar 17 1997 13:40 | 5 |
| Well, the DECtape formatting was the same for PDP-9/10/11/15, and
the two "extra" bits (18 bits of space for a 16-bit word) were
not used on PDP-11s. That makes me think the format was basically
the same as for the other machines.
|
| 1155.3 | Confirm hardware formats were same on DECtape | EVMS::EVERHART | | Mon Mar 17 1997 14:25 | 10 |
| Yes, pdp9, pdp10, and pdp11 DECtape was formatted the same. There were
programs (I used to use them at MIT now and then) that could read
and write pdp9 DECtape on pdp11, pdp11 DECtape on pdp9, pdp10
DECtape on pdp8, and various others. You could put the pdp11 DECtape
controller in a mode to read the "extra" 2 bits (ie, bits 16 and 17,
0-15 being easy) and reassemble the data by hand. File structures on
these DECtapes were of course completely different one from another;
KM9-15 tape looked nothing like pdp10 monitor looked nothing like
Dos-11 looked nothing like RSX11...
|
| 1155.4 | Then there was the TC12-F | HELIX::WELLCOME | Steve Wellcome SHR3-1/C22 Pole A22 | Tue Mar 18 1997 14:21 | 13 |
| Then there was the TC12-F LINCtape option, which let you read and
write DECtapes on a LINCtape drive. Since LINCtapes turned in the
opposite direction to DECtapes, and the data words were recorded
(more or less) as:
0 1 2 3 0 3 6 9
4 5 6 7 instead of 1 4 7 10
8 9 10 11 2 5 8 11
it got pretty interesting.
I might even have documentation on it, somewhere, although I'm not
sure I'd want to admit it....
|
| 1155.5 | Got answer | CSTMSO::SUPNIK | | Wed Mar 19 1997 16:48 | 7 |
| And the answer is...
PDP-11 DECtapes also worked from high order bit to low.
Thanks for your help, everyone.
/Bob
|