Files produced by the old "g7t" tape reading and decoding programs retain all uncorrected errors and thus may have characters with the wrong parity or even zero. The "g7t" programs also use intermediate files that are extensions of these formats, containing more raw information for the decoding process.
Column binary files (.CBN) are binary tape files which contain pairs of characters, the first of which is the 12-3 rows and the second the 4-9 rows of a card. The 9 or 3 row is in the least significant bit. The number of characters in a record must be even, and is normally 160, but trailing blank columns may be eliminated.
See the Notes for "g7t" for documentation on g7tedit, which was used in the preparation of some of the tapes but is also a useful (if basic) utility on its own.
The first four columns are for simulators. The Bob S. column is for Bob Supnik's 1401 simulator, easily available on the web. The next two columns are for another Bob working on a 1401 simulator and the old version of my simulator. Finally the Newcomer column is for the 1401 simulator here.
The A and F columns are for the "business" and "Fortran" chains for the 1403 printer, from Bob Supnik.
The last column is for my programs here. Where there are two characters, txt2bcd will accept either and bcd2txt will produce the first (business) unless -f (Fortran) is specified. At the far right some of the strange original BCD characters are described in parentheses. The code octal 20 is special, it is used on tape to represent 00 in core and so normally would not be printable. With bcd2txt the default is to convert it to "^" so it doesn't disappear when converting both ways, but with -b it will convert to a blank which is the normal case and should work with most editing tasks. This table is in the file asciibcd.h.
octal Bob S. Bob A. P. Old Newcomer A F Pierce
00 (Blank)
01 1 1 1 1 1 1 1
02 2 2 2 2 2 2 2
03 3 3 3 3 3 3 3
04 4 4 4 4 4 4 4
05 5 5 5 5 5 5 5
06 6 6 6 6 6 6 6
07 7 7 7 7 7 7 7
10 8 8 8 8 8 8 8
11 9 9 9 9 9 9 9
12 0 0 0 0 0 0 0
13 # # = = # # = # =
14 @ @ ' ' @ @ ' @ '
15 : : : : :
16 > > > > >
17 ( t Radical 0xFB { { (Tape Mark)
20 ^ c b ^ ^ (Cents or b with a stroke)
21 / / / / / / /
22 S S S S S S S
23 T T T T T T T
24 U U U U U U U
25 V V V V V V V
26 W W W W W W W
27 X X X X X X X
30 Y Y Y Y Y Y Y
31 Z Z Z Z Z Z Z
32 ' r | | | (Record Mark)
33 , , , , , , ,
34 % % ( % ( % ( % (
35 = = ^ ~
36 \ ' \ \ \
40 - - - - - - -
41 J J J J J J J
42 K K K K K K K
43 L L L L L L L
44 M M M M M M M
45 N N N N N N N
46 O O O O O O O
47 P P P P P P P
50 Q Q Q Q Q Q Q
51 R R R R R R R
52 ! ! ! ! - - !
53 $ $ $ $ $ $ $
54 * * * * * * *
55 ] ) ] ] ]
56 ; ; ; ; ;
57 _ d Delta 0x7F _ (Delta)
60 & & + + & & & & +
61 A A A A A A A
62 B B B B B B B
63 C C C C C C C
64 D D D D D D D
65 E E E E E E E
66 F F F F F F F
67 G G G G G G G
70 H H H H H H H
71 I I I I I I I
72 ? ? ? ? & & ?
73 . . . . . . .
74 ) o ) ) ) ) ) (Lozenge)
75 [ ( [ [ [
76 < < < < <
77 * " g Group Mark 0xCE } } (Group Mark)
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