[TUHS] 780 System III tape images

[TUHS] 780 System III tape images

[Al Kossow]

I've placed two sets of 800bpi 780 System III tape images
temporarily under http://bitsavers.org/sysIII

Curiously, they don't match. There were no dates on the tapes
which are originals.

[TUHS] 780 System III tape images

[Warren Toomey]

On Mon, Sep 24, 2007 at 07:40:23PM -0700, Al Kossow wrote:
> I've placed two sets of 800bpi 780 System III tape images
> temporarily under http://bitsavers.org/sysIII
> Curiously, they don't match. There were no dates on the tapes
> which are originals.

I've found tapcat.pl and used it to extract the records from the four tapes.
Here's a quick table with truncated MD5s of the 7 records from tape 1 of each
set, and of the cpio archive which is on tape 2 of each set.

Tape Record	What It Is	Set 1	 Set 2
---------------------------------------------------------
file0.dat 	boot record	ce3dab	 ce3dab
file1.dat 	mini-root	693861	 1b9183	different
file2.dat 	cpio binary	777632	 777632
file3.cpio 	/		5b6ba5	 5b6ba5
file4.cpio 	/usr/src/man	713ea0	 713ea0
file5.cpio 	/usr/src/rje	8d146b	 8d146b
file6.cpio 	/usr/src/graf	7e2afa	 7e2afa

tape2.cpio 	/usr		51b5b1	 a07403	different

tape2.cpio in set 2 seems to be slightly corrupt; cpio -ivt on the file
gives this warning:

  -rw-rw-r--   1 operator kmem         1052 Apr 12  1980 src/games/trk/win.c
  -rw-rw-r--   1 operator kmem         4147 Apr 12  1980 src/games/bj.s
  cpio: warning: skipped 840 bytes of junk
  -rw-rw-r--   1 operator kmem          122 Apr 12  1980 src/games/us.s
  -rw-rw-r--   1 operator kmem        10036 Apr 12  1980 src/games/mail.c

Otherwise, the contents of the two tape2 files appears to be identical, i.e.
the cpio timestamps on all the files match up.

The two file1.dat records differ at position 721; I haven't attempted to
dig any further with these files yet.

	Warren

[TUHS] 780 System III tape images

[Andrew Warkentin]

Al Kossow wrote:

>I've placed two sets of 800bpi 780 System III tape images
>temporarily under http://bitsavers.org/sysIII
>
>Curiously, they don't match. There were no dates on the tapes
>which are originals.
>  
>
Why do I get read errors on the second file on the first tapes of both 
sets under SIMH? I didn't think it was even possible for tape I/O errors 
to occur under SIMH unless the image is corrupted.

[TUHS] 780 System III tape images

[Andrew Warkentin]

Al Kossow wrote:

>I've placed two sets of 800bpi 780 System III tape images
>temporarily under http://bitsavers.org/sysIII
>
>Curiously, they don't match. There were no dates on the tapes
>which are originals.
>
>_______________________________________________
>TUHS mailing list
>TUHS at minnie.tuhs.org
>https://minnie.tuhs.org/mailman/listinfo/tuhs
>
>
>  
>
Why do I get read errors on the second file on the first tapes of both 
sets under SIMH? I didn't think it was even possible for tape I/O errors 
to occur under SIMH unless the image is corrupted.

[TUHS] 780 System III tape images

[Al Kossow]

Andrew Warkentin wrote:
>
> Why do I get read errors on the second file on the first tapes of both 
> sets under SIMH? 

does it say which block number failed?

[TUHS] 780 System III tape images

[Warren Toomey]

> Al Kossow wrote:
> >I've placed two sets of 800bpi 780 System III tape images
> >temporarily under http://bitsavers.org/sysIII

On Wed, Sep 26, 2007 at 05:42:21PM -0600, Andrew Warkentin wrote:
> Why do I get read errors on the second file on the first tapes of both 
> sets under SIMH? I didn't think it was even possible for tape I/O errors 
> to occur under SIMH unless the image is corrupted.

Hmm, I seem to have lost the tools I used to use to manipulate tap files.
Can someone e-mail in pointers to useful tap tools?

Thanks,
	Warren