5 Jun
2015
5 Jun
'15
7:57 p.m.
I have a copy of an 11/730 console tape which I have been told is in EXCHANGE format as
created by the CONSCOPY utility. Can any of the VMS experts here help this VMS noob learn
how to translate that into a raw block-level image of the corresponding TU58 tape, which I
might be able to use with a TU58 emulator?
I see that the EXCHANGE image is 512 bytes longer than a full TU58 tape. Could it be as
simple as chopping off the first or last 512 bytes? I'm not quite at the point yet
where I know what a console tape ought to look like in a hex editor, so I can't
clearly see whether that might work yet.
I'm presently starting to work on getting some version of VMS running on an emulated
11/780 under simh. So with any luck, I may have a functioning VMS environment before too
long, even though I haven't managed to boot up my real 11/730 yet. My end goal is to
use that console tape image with some TU58 emulator to boot up my real VAX. I have some
original console tapes for it, but they no longer seem to be readable. I did get my
machine to examine one of them quite a bit before deciding it wasn't suitable, so
maybe there is still some recoverable data on those tapes... but none of them seem to be
sufficiently error-free to boot my machine.
I'm presently working on booting it from a downloaded console tape image, but getting
tu58em and my 11/730 to like each other is still an ongoing project. Once I get there, I
think that this EXCHANGE format image that I have is the same console tape version as my
unreadable real tapes, and newer than the other downloaded image that I'm presently
trying to use, so it would be nice to be able to get it into a format that I can use
directly.
Thanks in advance for any clues!
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
5 Jun
5 Jun
10:05 p.m.
On 2015-06-06 01:57, Mark J. Blair wrote:
I have a copy of an 11/730 console tape which I have
been told is in EXCHANGE format as created by the CONSCOPY utility. Can any of the VMS
experts here help this VMS noob learn how to translate that into a raw block-level image
of the corresponding TU58 tape, which I might be able to use with a TU58 emulator?
I see that the EXCHANGE image is 512 bytes longer than a full TU58 tape. Could it be as
simple as chopping off the first or last 512 bytes? I'm not quite at the point yet
where I know what a console tape ought to look like in a hex editor, so I can't
clearly see whether that might work yet.
I'm presently starting to work on getting some version of VMS running on an emulated
11/780 under simh. So with any luck, I may have a functioning VMS environment before too
long, even though I haven't managed to boot up my real 11/730 yet. My end goal is to
use that console tape image with some TU58 emulator to boot up my real VAX. I have some
original console tapes for it, but they no longer seem to be readable. I did get my
machine to examine one of them quite a bit before deciding it wasn't suitable, so
maybe there is still some recoverable data on those tapes... but none of them seem to be
sufficiently error-free to boot my machine.
I'm presently working on booting it from a downloaded console tape image, but getting
tu58em and my 11/730 to like each other is still an ongoing project. Once I get there, I
think that this EXCHANGE format image that I have is the same console tape version as my
unreadable real tapes, and newer than the other downloaded image that I'm presently
trying to use, so it would be nice to be able to get it into a format that I can use
directly.
Thanks in advance for any clues!
Unless I'm really confused, "EXCHANGE" is not a format. EXCHANGE is a
program under VMS to read/write RT-11 format file systems, which is what
you usually had on the FE media.
However, if you actually have EXCHANGE create an image copy of a
tape/disk, and it actually is 512 bytes larger than the device, then I
guess EXCHANGE have some sort of image dump format with some extra block
with some meta-data.
See if you can spot the RT-11 file system in there.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
10:08 p.m.
On Jun 5, 2015, at 19:05 , Johnny Billquist <bqt at
update.uu.se> wrote:
See if you can spot the RT-11 file system in there.
Aha, is the console tape supposed to be in RT-11 format? That's something I can look
for. My home-grown RT-11 filesystem finagling utility barfed on my "suspected
good" raw image, but that could very well be a bug in my own code. I'll dig in
with a hex editor tonight and look for the filesystem header blocks.
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
10:12 p.m.
On 2015-06-06 04:08, Mark J. Blair wrote:
I definitely know that this is the case for the VAX-11/78x and VAX-86x0
machines. And you use EXCHANGE to access the files.
I haven't properly looked at the 11/750, 11/730 or 11/725, but I don't
think EXCHANGE understands anything else but the RT-11 filesystem. As
far as I know, that was EXCHANGE existed for. It might be able to read
DOS-11 tapes as well. (If we talk about pure 1/2" magtape.)
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
On Jun 5, 2015, at 19:05 , Johnny Billquist
<bqt at update.uu.se> wrote:
See if you can spot the RT-11 file system in there.
Aha, is the console tape supposed to be in RT-11 format? That's something I can look
for. My home-grown RT-11 filesystem finagling utility barfed on my "suspected
good" raw image, but that could very well be a bug in my own code. I'll dig in
with a hex editor tonight and look for the filesystem header blocks. 
6 Jun
6 Jun
3:14 p.m.
FWIW, I can confirm that the 730 console tapes are in RT11 format, as are
the 750's. DEC standardized on that format for console media, even though
there is no actual PDP-11 involved in the 725/730/750.
And EXCHANGE has the ability to create "virtual" media images on disk.
The CONSCOPY script creates a virtual TU58 image file and then copies all
the files from the real console TU58 to the virtual copy. Why the copy has
an extra 512 bytes, I don't know.
I agree with Johnny - dump out the image and look for the RT11 directory.
Bob
3:20 a.m.
I have a copy of an 11/730 console tape which I have been told is in EXCHANGE
format as created by the CONSCOPY utility. Can any of the VMS experts here
help this VMS noob learn how to translate that into a raw block-level image
of the corresponding TU58 tape, which I might be able to use with a TU58
emulator?
I've never actually used it but I thought CONSCOPY sounded familar from
somewhere. I had a quick look on my VAX/VMS V5.5-2 system and found
SYS$UPDATE:CONSCOPY.COM. It is probably to be found in the same place on
every other version of VAX/VMS. Below are some comments from the top of the
file.
Regards,
Peter Coghlan.
$ ! Copyright (c) 1987 Digital Equipment Corporation. All rights reserved.
$ !
$ ! CONSCOPY -- Save or Restore a console medium
$ !
$ ! Inputs:
$ ! P1 - Kit type: 8600 or 8200 or 78x or 750 or 730
$ ! P2 - Function: SAVE or RESTORE
$ ! P3 - Files-11 virtual disk name
$ ! P4 - Console device drive
$ ! P5 - File to be written on the bootblock of the console medium.
$ ! Optional. The defaults are:
$ ! 8600- RT11FB.SYS
$ ! 78x - CONSOL.SYS
$ ! 8200- BOOT58.EXE
$ ! 8300- BOOT58.EXE
$ ! 750 - BOOT58.EXE
$ ! 730 - BOOT.EXE
$ !
$ ! This program saves or restores a console medium. It uses the native
$ ! mode utility EXCHANGE to copy and re-format files between a user medium
$ ! (Files-11 format) and a console medium (RT-11 format).
3334
days inactive
3335
days old
5 comments
4 participants
participants (4)
-
bob＠jfcl.com -
bqt＠update.uu.se -
cctalk＠beyondthepale.ie -
nf6x＠nf6x.net