[Simh] Looking for clues: MAKECD; CDROM format?

Sun May 10 17:47:15 EDT 2015

In exploring my archive of backup tapes, I found a non-backup tape image
that is rather curious.

It's an ANSI labeled tape, D format blocked 54 512-byte records/block.
The second volume says it's U format, but in fact the D format continues.
Stripping the RCWs, I get 8-bit data with a header that's readable, but
I don't
recognize it.  Does anyone here?

Here's what I see:
  The tape labels are consistent with the data, and show that it was
written on TOPS-10.
  The file name in the tape label is DSKC.E36
  It appears to be a CD image, or perhaps a tape meant to go to a
service to burn one.
  There's a reference to MAKECD %1(7)
   It may be a KLAD pack. (I suspect as sent to KLH when he was working
on klh10.)
   After the first block, the data is pretty random; I don't see ascii
text.  That may
    mean that it's compressed, or packed in some format.  Or it may just
be an
   artifact of the data.  Strings rarely finds more than a few adjacent
characters,
   but things like "KL", "LAT" and so on appear more frequently than I'd
call random.
   Linux 'file' doesn't recognize it. 
   extracting it in binary and calling it an ISO, linux won't mount it
as iso9660.
   I don't believe it's files-11.
   It might be Ultrix CDFS - anyone know that format/a linux tool?

I haven't found MAKECD in my archives (but they're big, so I haven't
given up.)
That search will be easier when my new tape reader is finished...

Meantime, does anyone recognize this format (this is after the RCW
removal/repacking):

ANSI tape label:VOL1DSKC1                            D%AT10 
028711                            3
ANSI tape label:UVL1000000000000000000
ANSI tape label:HDR1DSKC.E36         DSKC1 00010001001020 94161 94161
000000DECSYSTEM10
ANSI tape label:HDR2D2786400512000000000001000002

Record size 27648 read at file 1, record 1 of KL1026_DSKC_19940610_1of2.tap
0000: 6b 6c 68 33 36 42 49 54 53 30 31 32 30 34 38 44   k l h 3 6 B I T
S 0 1 2 0 4 8 D
0010: 52 50 30 36 00 00 30 30 30 31 30 30 30 31 68 30   R P 0 6     0 0
0 1 0 0 0 1 h 0
0020: 54 4f 50 53 2d 31 30 00 00 00 00 00 00 00 00 4d   T O P S - 1
0                 M
0030: 41 4b 45 43 44 20 25 31 28 37 29 00 00 00 00 00   A K E C D   % 1
( 7 )
0040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
4b                                 K
0050: 4c 41 44 31 30 20 4b 4c 44 20 44 45 43 31 30 20   L A D 1 0   K L
D   D E C 1 0
0060: 53 69 6e 67 6c 65 2d 43 50 55 20 2d 20 44 20 32   S i n g l e - C
P U   -   D   2
0070: 38 37 31 00 00 00 00 4b 4c 31 30 32 36 20 54 69   8 7 1         K
L 1 0 2 6   T i
0080: 6d 65 73 68 61 72 69 6e 67 20 44 65 76 65 6c 6f   m e s h a r i n
g   D e v e l o
0090: 70 6d 65 6e 74 20 73 79 73 74 65 6d 27 73 20 44   p m e n t   s y
s t e m ' s   D
00a0: 53 4b 43 20 61 73 20 6f 66 20 31 2d 4a 75 6e 2d   S K C   a s   o
f   1 - J u n -
00b0: 31 39 39 34 00 00 00 00 00 00 00 00 00 00 00 00   1 9 9 4
00f0: 00 00 00 00 00 00 00 43 6f 6e 66 69 64 65 6e 74                 C
o n f i d e n t
0100: 69 61 6c 20 61 6e 64 20 70 72 6f 70 72 69 65 74   i a l   a n d  
p r o p r i e t
0110: 61 72 79 20 69 6e 66 6f 72 6d 61 74 69 6f 6e 20   a r y   i n f o
r m a t i o n
0120: 29 20 44 69 67 69 74 61 6c 20 45 71 75 69 70 6d   )   D i g i t a
l   E q u i p m
0130: 65 6e 74 20 43 6f 72 70 6f 72 61 74 69 6f 6e 20   e n t   C o r p
o r a t i o n
0140: 31 39 39 34 2e 20 41 6c 6c 20 52 69 67 68 74 73   1 9 9 4 .   A l
l   R i g h t s
0150: 20 52 65 73 65 72 76 65 64 2e 00 00 00 00 00 00     R e s e r v e d .
0170: 00 00 00 00 00 00 00 30 30 30 30 30 30 30 30 30                 0
0 0 0 0 0 0 0 0
0180: 30 30 34 42 39 43 34 00 00 00 00 00 00 00 00 00   0 0 4 B 9 C 4
07f0: 00 00 00 00 00 00 4c 43 47 44 45 43 54 4c 57 53               L C
G D E C T L W S
0800: 04 0d c1 25 c0 57 00 12 62 04 14 01 09 00 43 40         %   W    
b           C @
0810: 11 10 04 54 01 04 50 75 dc 00 08 04 96 01 5c 00         T     P
u             \
0820: 20 00 0a 01 05 70 80 00 40 42 0c 15 c6 04 14 00             p     @ B
0830: 9f 70 01 60 87 02 00 1d c0 7c c0 27 dc 00 2a 10     p  
`           |   '     *

-- 
This communication may not represent my employer's views,
if any, on the matters discussed. 

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