12 Jan
2004
12 Jan
'04
10:56 p.m.
I've got a TPC image, that was originally from a MM: drive, and I've written it
back out to a MU: drive (4mm in this case). I'm just trying to read the tape, I'm
not trying to do anything fancy like boot from it. Is there any reason that I should have
trouble doing this?
Zane
--
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| Zane H. Healy | UNIX Systems Administrator |
| healyzh(a)aracnet.com (primary) | OpenVMS Enthusiast |
| | Classic Computer Collector |
+----------------------------------+----------------------------+
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13 Jan
13 Jan
6:13 a.m.
Zane H. Healy wrote:
I've got a TPC image, that was originally from a
MM: drive, and I've written it back out to a MU: drive (4mm in this case). I'm
just trying to read the tape, I'm not trying to do anything fancy like boot from it.
Is there any reason that I should have trouble doing this?
Zane
What OS, and how are you trying to read it, what format is the tape in,
how did you create it, etc.?
Are you trying to read it as file structured, or raw?
Was it written with the same tape drive you are trying to read it from?
No.
Differences in the drives
compression method
density
abaility to handle >90m tapes
Yes (or No)
Dirty heads.
Block size > than the PDP11 software can handle
Different format (DOS vs. ANSI vs. UNFORMATTED)
Badly written tape (software failure)
8:56 a.m.
Zane H. Healy wrote:
The OS is RSTS/E and the tape is ANSI, at least I think it's ANSI and not DOS, I'd
have to check to be positive. This much I do know, I've converted the TPC file to a
SIMH TAP file, and read it without any problem under E11 and SIMH. I've even used E11
to convert it to a RSX TAP image, which I've written to 4mm DAT on the same drive, and
I can't read it. I've also taken the TPC file and written it on VMS on the same
model DAT drive.
What really mystifies me is that I'm able to read the tape without any problem using
E11 running RSTS/E. Yet, I can't read either DAT tape that I've made. I've
been able to read other tapes made this way just fine.
Zane
--
--
| Zane H. Healy | UNIX Systems Administrator |
| healyzh(a)aracnet.com (primary) | OpenVMS Enthusiast |
| | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| PDP-10 Emulation and Zane's Computer Museum. |
| http://www.aracnet.com/~healyzh/ |
I've got a TPC image, that was originally from
a MM: drive, and I've written it back out to a MU: drive (4mm in this case). I'm
just trying to read the tape, I'm not trying to do anything fancy like boot from it.
Is there any reason that I should have trouble doing this?
Zane
What OS, and how are you trying to read it, what format is the tape in,
how did you create it, etc.? 
9:25 a.m.
On Tue, 13 Jan 2004, Zane H. Healy wrote:
The OS is RSTS/E and the tape is ANSI, at least I
think it's ANSI and not DOS, I'd have to check to be positive. This much I do
know, I've converted the TPC file to a SIMH TAP file, and read it without any problem
under E11 and SIMH. I've even used E11 to convert it to a RSX TAP image, which
I've written to 4mm DAT on the same drive, and I can't read it. I've also
taken the TPC file and written it on VMS on the same model DAT drive.
What really mystifies me is that I'm able to read the tape without any problem using
E11 running RSTS/E. Yet, I can't read either DAT tape that I've made. I've
been able to read other tapes made this way just fine.
Beware that *many* DDS1
drives cannot do variable-sized blocks very
well... if memory serves me right, RSTS BACKUP format uses many
block sizes in a single backup file:
80 - ANSI header
14 - RSTS file header
1024
2048\__ data block sizes, often +4
4096/
8192
This might be your problem.. even though the tape image is
fine, the drive doesnt let you use arbitrary block sizes.
This may or may not apply to your drive.. Nico might know
more about this- I just ran into this when writing an ASPI
layer for my software... I was unable to tell the DDS drive
to switch to 64-byte blocks.. it insisted on 512-b blocks.
Cheers,
Fred
10:54 a.m.
Beware that *many* DDS1 drives cannot do
variable-sized blocks very
well... if memory serves me right, RSTS BACKUP format uses many
block sizes in a single backup file:
80 - ANSI header
14 - RSTS file header
1024
2048\__ data block sizes, often +4
4096/
8192
This might be your problem.. even though the tape image is
fine, the drive doesnt let you use arbitrary block sizes.
This may or may not apply to your drive.. Nico might know
more about this- I just ran into this when writing an ASPI
layer for my software... I was unable to tell the DDS drive
to switch to 64-byte blocks.. it insisted on 512-b blocks.
Interesting.... BTW, the DDS1 drive I'm using is a DEC TLZ06. Any idea if
this might also be a problem with an Exabyte 8500 tape drive? It would be
easier for me to attach an Exabyte 8500, than it would be to get a TZ30
hooked up. Well, maybe not that much easier, I think all the tapes are
buried in the same spot :^/
Zane
6:32 p.m.
On Tue, 13 Jan 2004, Zane H. Healy wrote:
Interesting.... BTW, the DDS1 drive I'm using is
a DEC TLZ06. Any idea if
Hmm, wasnt the TLZ06 a DDS2 drive? At any rate, yeah,
this drive
might very well have this "problem" .. I had it with many DDS
drives, might even have been a TLZ in that stack... I *do* know
I tested it with a TLZ04.
this might also be a problem with an Exabyte 8500 tape
drive? It would be
Cant remember... only had a 8200 at the time, and cant remember
the
results of that..
--f
--
Fred N. van Kempen, DEC (Digital Equipment Corporation) Collector/Archivist
Visit the VAXlab Project at http://VAXlab.pdp11.nl/
Visit the Archives at http://www.pdp11.nl/
Email: waltje(a)pdp11.nl BUSSUM, THE NETHERLANDS / Mountain View, CA, USA
6:44 p.m.
On Tue, 13 Jan 2004, Zane H. Healy wrote:
Thanks Fred! At least now I know I'm probably not crazy. :^/ Now to
decide if I get a TZ30 up and running, or try the Exabyte 8500. I might go
with the 8500 as it's in a SCSI box already, and I should be able to hook it
up to the /23+ without to much trouble (the /73 would require some
rewiring).
Zane
Interesting.... BTW, the DDS1 drive I'm
using is a DEC TLZ06. Any idea if
Hmm, wasnt the TLZ06 a DDS2 drive? At any rate, yeah, this drive
might very well have this "problem" .. I had it with many DDS
drives, might even have been a TLZ in that stack... I *do* know
I tested it with a TLZ04.
this might also be a problem with an Exabyte 8500
tape drive? It would be
Cant remember... only had a 8200 at the time, and cant remember the
results of that..
--f
6:56 p.m.
On Tue, 13 Jan 2004, Zane H. Healy wrote:
Thanks Fred! At least now I know I'm probably not
crazy. :^/ Now to
decide if I get a TZ30 up and running, or try the Exabyte 8500. I might go
with the 8500 as it's in a SCSI box already, and I should be able to hook it
up to the /23+ without to much trouble (the /73 would require some
rewiring).
I had no trouble hooking up TZ30's to (cheap-and-slow) AHA1542
controllers in a PC.
--f
6:47 p.m.
this might
also be a problem with an Exabyte 8500 tape drive? It would be
Cant remember...
only had a 8200 at the time, and cant remember the
results of that..
--f
12:47 p.m.
Fred N. van Kempen wrote:
On Tue, 13 Jan 2004, Zane H. Healy wrote:
Write a Quick & dirty program to read the blocks, printing out
the size of each one. Something roughly like (not tested)
10 open "mu0:" for input as file 5%
20 get #5%
30 print recount
40 goto 20
99 end
look at the sizes reported. You will probably get an error
for the EOF markers, but we are mostly interested in the beginning
of the tape. Should be something like "80 80 512 512 512 ... EOF"
for an ANSI tape, or "14 512 512 512...EOF" for a DOS tape.
If it begins with >80 character blocks, you're missing the headers.
If you need to read past EOF's, try
10 open "mu0:" for input as file 5%
15 on error goto 80
20 get #5%
30 print recount
40 goto 20
80 print "[EOF]"
90 resume 20
99 end
Be prepared to kill it, because it will skip all errors. (It's a really
dumb program)
You may also want to try (this is from memory, so may be wrong)
I can't remember if this was at DCL or at the basic prompt.
$ assign mu0:.ansi
or
$ assign mu0:.dos
to force the tape format before trying to get a dir.
I think "$mount/format=ansi" or "$mount/format=dos"
will also do it too.
The OS is RSTS/E and the tape is ANSI, at least I
think it's ANSI and not DOS, I'd have to check to be positive. This much I do
know, I've converted the TPC file to a SIMH TAP file, and read it without any problem
under E11 and SIMH. I've even used E11 to convert it to a RSX TAP image, which
I've written to 4mm DAT on the same drive, and I can't read it. I've also
taken the TPC file and written it on VMS on the same model DAT drive.
What really mystifies me is that I'm able to read the tape without any problem using
E11 running RSTS/E. Yet, I can't read either DAT tape that I've made. I've
been able to read other tapes made this way just fine.
Beware that *many* DDS1 drives cannot do variable-sized blocks very
well... if memory serves me right, RSTS BACKUP format uses many
block sizes in a single backup file:
80 - ANSI header
14 - RSTS file header
1024
2048\__ data block sizes, often +4
4096/
8192
This might be your problem.. even though the tape image is
fine, the drive doesnt let you use arbitrary block sizes.
This may or may not apply to your drive.. Nico might know
more about this- I just ran into this when writing an ASPI
layer for my software... I was unable to tell the DDS drive
to switch to 64-byte blocks.. it insisted on 512-b blocks.
Cheers,
Fred
7:25 p.m.
This might be your problem.. even though the tape image is
fine, the drive doesnt let you use arbitrary block sizes.
This may or may not apply to your drive.. Nico might know
more about this- I just ran into this when writing an ASPI
layer for my software... I was unable to tell the DDS drive
to switch to 64-byte blocks.. it insisted on 512-b blocks.
Correct. I cant remember ever having seen SCSI drives with block sizes
different from 512 bytes.
The software I use for copying tapes, is able to make block-to-block copies,
regardless of logical sizes. The only problem is that I have no TK drives.
Despite my involvement in media conversion since 1986 or so, I have sold
only one TK drive, and that one is in Norway. Cant even be sure about the
type. As it happens, I go to Norway this weekend for PM at that customer
(Tax Directorate), and I can check which one it is. What then could be a
possibility, is that I convert the tape next time I get there, which will be
around april 1 (no joke intended).
Nico
9:38 p.m.
On Wed, Jan 14, 2004 at 07:25:09AM +0100, Nico de Jong wrote:
Correct. I cant remember ever having seen SCSI drives
with block sizes
different from 512 bytes.
I have some 4GB drives that were once 524 bytes-per-block. A couple of
hours with an AHA1542 and its low-level formatting firmware fixed that!
-ethan
--
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South Pole Station
PSC 468 Box 400 Temp -21.2 F (-29.6 C) Windchill -43.6 F (-42 C)
APO AP 96598 Wind 7.6 kts Grid 050 Barometer 683.6 mb (10492. ft)
Ethan.Dicks(a)amanda.spole.gov http://penguincentral.com/penguincentral.html
10:13 p.m.
---- Original Message -----
From: "Ethan Dicks" <dickset(a)amanda.spole.gov>
On Wed, Jan 14, 2004 at 07:25:09AM +0100, Nico de Jong
wrote:
You are probably speaking of SCSI disks. I talk about streamers. I have seen
some funny formats on streamers, but those were QIC-02 and similar.
Nico
Correct. I cant remember ever having seen SCSI
drives with block sizes
different from 512 bytes.
I have some 4GB drives that were once 524 bytes-per-block. A couple of
hours with an AHA1542 and its low-level formatting firmware fixed that!
10:42 p.m.
On Wed, Jan 14, 2004 at 10:13:32AM +0100, Nico de Jong wrote:
---- Original Message -----
From: "Ethan Dicks" <dickset(a)amanda.spole.gov>
Oh... sorry... yes... you said "SCSI drives" and I didn't pick up
"tape
drives" from that.
-ethan
--
Ethan Dicks, A-130-S Current South Pole Weather at 14-Jan-2004 09:40 Z
South Pole Station
PSC 468 Box 400 Temp -22.5 F (-30.3 C) Windchill -40.9 F (-40.5 C)
APO AP 96598 Wind 6.6 kts Grid 053 Barometer 683.6 mb (10492. ft)
Ethan.Dicks(a)amanda.spole.gov http://penguincentral.com/penguincentral.html
On Wed, Jan 14, 2004 at 07:25:09AM +0100, Nico de
Jong wrote:
You are probably speaking of SCSI disks. I talk about streamers. Correct. I cant remember ever having seen SCSI
drives with block sizes
different from 512 bytes.
I have some 4GB drives that were once 524 bytes-per-block. A couple of
hours with an AHA1542 and its low-level formatting firmware fixed that!
21 Jan
21 Jan
3:48 a.m.
----- Original Message -----
From: "Nico de Jong" <nico(a)farumdata.dk>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk(a)classiccmp.org>
Sent: Wednesday, January 14, 2004 7:25 AM
Subject: Re: Odd PDP-11 tape related question
The drive in question is a DLT2000
Nico
This might be your problem.. even though the tape image is
fine, the drive doesnt let you use arbitrary block sizes.
This may or may not apply to your drive.. Nico might know
more about this- I just ran into this when writing an ASPI
layer for my software... I was unable to tell the DDS drive
to switch to 64-byte blocks.. it insisted on 512-b blocks.
Correct. I cant remember ever having seen SCSI drives with block sizes
different from 512 bytes.
Despite my involvement in media conversion since 1986 or so, I have sold
only one TK drive, and that one is in Norway.
7489
days inactive
7497
days old
14 comments
5 participants
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