Nine track file marks, Burroughs

[Dennis Boone]

Folks,

I've now seen two Burroughs tapes where some of the expected file marks
between labels and file data were apparently missing.

I think a reasonable description of these is "Burroughs/Unisys B6x00
'Library/Maintenance' tapes with ANSI-69 labels"

Reading drive is a Cipher GCR Cachetape with SCSI interface

The one I read yesterday read in streaming mode and reported no read
errors.  I tried re-reading it today, and it read in start-stop mode,
but still didn't have the missing file marks.  (It also encountered a
few errors, and eventually ended up sticking to the head, this time.
Guess that bake cycle was a one-shot, which isn't a surprise.)

This tape is a "Burroughs Series 7 / 100% Tested / 3200 FCI" 1200 foot
reel written at 1600 BPI in 1986.

Here's the beginning of the tape:

  file 1 record 1 size 80
  00000000: e5 d6 d3 f1 f0 f3 f6 f1 f3 f0 40 d7 d9 d6 c7 d9  VOL1036130 PROGR
  00000010: c1 d4 40 40 40 40 40 40 40 40 40 40 f6 f5 f3 f0  AM          6530
  00000020: f3 f0 f5 f0 f3 40 40 40 40 40 40 40 40 40 40 40  30503           
  00000030: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40                  
  00000040: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 f1                 1
  file 1 record 2 size 80
  00000000: c8 c4 d9 f1 c6 c9 d3 c5 f0 f0 f0 40 40 40 40 40  HDR1FILE000     
  00000010: 40 40 40 40 40 d7 d9 d6 c7 d9 c1 f0 f0 f0 f1 f0       PROGRA00010
  00000020: f0 f0 f1 f0 f0 f0 f1 f0 f0 40 f8 f6 f2 f0 f2 40  001000100 86202 
  00000030: f8 f6 f2 f3 f2 40 f0 f0 f0 f0 f0 f0 f0 f0 f0 f0  86232 0000000000
  00000040: f0 f0 f0 40 c1 f9 40 40 40 40 40 40 40 40 40 40  000 A9          
  file 1 record 3 size 80
  00000000: c8 c4 d9 f2 e4 f0 f1 f0 f2 f4 f0 f1 f0 f2 f4 f3  HDR2U01024010243
  00000010: f0 f1 f0 f1 f0 f0 f0 f0 f3 f0 f0 f0 f0 f0 f0 f0  0101000030000000
  00000020: f0 f0 f0 f0 f0 f6 f4 f0 f0 f1 f3 40 f0 f0 f6 f4  00000640013 0064
  00000030: 40 40 f0 f6 40 40 40 40 40 40 40 40 40 40 40 40    06            
  00000040: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40                  
  file 1 record 4 size 2070
  00000000: 40 00 00 00 00 01 00 00 00 00 00 00 12 03 03 04   ...............

...etc.

Is oddness with file marks something others have seen with Burroughs
tapes?  Something the Cipher drive is known for?  Moon phase?  Incorrect
fifth digit of my SSN?  I've not had this missing file mark problem with
tapes written on other vendors systems - Prime, IBM, DEC.

Cluebats appreciated.

De