What is now recode evolved out, through many transformations
really, from a set of programs which were originally written in
COMPASS, Control Data Corporation's assembler, with bits in FORTRAN,
and later rewritten in CDC 6000 Pascal. The CDC heritage shows by the
fact some old CDC charsets are still supported.
The recode author used to be familiar with CDC Scope-NOS/BE and
Kronos-NOS, and many CDC formats. Reading CDC tapes directly on other
machines is often a challenge, and recode does not always solve
it. It helps having tapes created in coded mode instead of binary mode,
and using S (Stranger) tapes instead of I (Internal) tapes.
ANSI labels and multi-file tapes might be the source of trouble. There are
ways to handle a few Cyber Record Manager formats, but some of them might
be quite difficult to decode properly after the transfer is done.
The recode program is usable only for a small subset of NOS text
formats, and surely not with binary textual formats, like UPDATE
or MODIFY sources, for example. recode is not especially
suited for reading 8/12 or 56/60 packing, yet this could easily arranged
if there was a demand for it. It does not have the ability to translate
Display Code directly, as the ASCII conversion implied by tape drivers
or FTP does the initial approximation. recode can decode 6/12
caret notation over Display Code already mapped to ASCII.
This code is not available in recode, but repeated here for
reference. This is a 6-bit code used on CDC mainframes.
Octal display code to graphic Octal display code to octal ASCII 00 : 20 P 40 5 60 # 00 072 20 120 40 065 60 043 01 A 21 Q 41 6 61 [ 01 101 21 121 41 066 61 133 02 B 22 R 42 7 62 ] 02 102 22 122 42 067 62 135 03 C 23 S 43 8 63 % 03 103 23 123 43 070 63 045 04 D 24 T 44 9 64 " 04 104 24 124 44 071 64 042 05 E 25 U 45 + 65 _ 05 105 25 125 45 053 65 137 06 F 26 V 46 - 66 ! 06 106 26 126 46 055 66 041 07 G 27 W 47 * 67 & 07 107 27 127 47 052 67 046 10 H 30 X 50 / 70 ' 10 110 30 130 50 057 70 047 11 I 31 Y 51 ( 71 ? 11 111 31 131 51 050 71 077 12 J 32 Z 52 ) 72 < 12 112 32 132 52 051 72 074 13 K 33 0 53 $ 73 > 13 113 33 060 53 044 73 076 14 L 34 1 54 = 74 @ 14 114 34 061 54 075 74 100 15 M 35 2 55 75 \ 15 115 35 062 55 040 75 134 16 N 36 3 56 , 76 ^ 16 116 36 063 56 054 76 136 17 O 37 4 57 . 77 ; 17 117 37 064 57 056 77 073
In older times, : used octal 63, and octal 0 was not a character. The table above shows the ASCII glyph interpretation of codes 60 to 77, yet these 16 codes were once defined differently.
There is no explicit end of line in Display Code, and the Cyber Record
Manager introduced many new ways to represent them, the traditional end of
lines being reachable by setting RT to `Z'. If 6-bit bytes
in a file are sequentially counted from 1, a traditional end of line
does exist if bytes 10*n+9 and 10n+10 are both zero for a
given n, in which case these two bytes are not to be interpreted as
::. Also, up to 9 immediately preceeding zero bytes, going backward,
are to be considered as part of the end of line and not interpreted as
:(12).
This charset is available in recode under the name
CDC-NOS, with NOS as an acceptable alias.
This is one of the charsets in use on CDC Cyber NOS systems to represent ASCII, sometimes named NOS 6/12 code for coding ASCII. This code is also known as caret ASCII. It is based on a six bits character set in which small letters and control characters are coded using a ^ escape and, sometimes, a @ escape.
The routines given here presume that the six bits code is already expressed in ASCII by the communication channel, with embedded ASCII ^ and @ escapes.
Here is a table showing which characters are being used to encode each ASCII character.
000 ^5 020 ^# 040 060 0 100 @A 120 P 140 @G 160 ^P 001 ^6 021 ^[ 041 ! 061 1 101 A 121 Q 141 ^A 161 ^Q 002 ^7 022 ^] 042 " 062 2 102 B 122 R 142 ^B 162 ^R 003 ^8 023 ^% 043 # 063 3 103 C 123 S 143 ^C 163 ^S 004 ^9 024 ^" 044 $ 064 4 104 D 124 T 144 ^D 164 ^T 005 ^+ 025 ^_ 045 % 065 5 105 E 125 U 145 ^E 165 ^U 006 ^- 026 ^! 046 & 066 6 106 F 126 V 146 ^F 166 ^V 007 ^* 027 ^& 047 ' 067 7 107 G 127 W 147 ^G 167 ^W 010 ^/ 030 ^' 050 ( 070 8 110 H 130 X 150 ^H 170 ^X 011 ^( 031 ^? 051 ) 071 9 111 I 131 Y 151 ^I 171 ^Y 012 ^) 032 ^< 052 * 072 @D 112 J 132 Z 152 ^J 172 ^Z 013 ^$ 033 ^> 053 + 073 ; 113 K 133 [ 153 ^K 173 ^0 014 ^= 034 ^@ 054 , 074 < 114 L 134 \ 154 ^L 174 ^1 015 ^ 035 ^\ 055 - 075 = 115 M 135 ] 155 ^M 175 ^2 016 ^, 036 ^^ 056 . 076 > 116 N 136 @B 156 ^N 176 ^3 017 ^. 037 ^; 057 / 077 ? 117 O 137 _ 157 ^O 177 ^4
This charset is available in recode under the name Bang-Bang.
This code, in use on Cybers at Universit'e de Montr'eal mainly, served to code a lot of French texts. The original name of this charset is ASCII cod'e Display. This code is also known as Bang-bang. It is based on a six bits character set in which capitals, French diacritics and a few others are coded using an ! escape followed by a single character, and control characters using a double ! escape followed by a single character.
The routines given here presume that the six bits code is already expressed in ASCII by the communication channel, with embedded ASCII ! escapes.
Here is a table showing which characters are being used to encode each ASCII character.
000 !!@ 020 !!P 040 060 0 100 @ 120 !P 140 !@ 160 P 001 !!A 021 !!Q 041 !" 061 1 101 !A 121 !Q 141 A 161 Q 002 !!B 022 !!R 042 " 062 2 102 !B 122 !R 142 B 162 R 003 !!C 023 !!S 043 # 063 3 103 !C 123 !S 143 C 163 S 004 !!D 024 !!T 044 $ 064 4 104 !D 124 !T 144 D 164 T 005 !!E 025 !!U 045 % 065 5 105 !E 125 !U 145 E 165 U 006 !!F 026 !!V 046 & 066 6 106 !F 126 !V 146 F 166 V 007 !!G 027 !!W 047 ' 067 7 107 !G 127 !W 147 G 167 W 010 !!H 030 !!X 050 ( 070 8 110 !H 130 !X 150 H 170 X 011 !!I 031 !!Y 051 ) 071 9 111 !I 131 !Y 151 I 171 Y 012 !!J 032 !!Z 052 * 072 : 112 !J 132 !Z 152 J 172 Z 013 !!K 033 !![ 053 + 073 ; 113 !K 133 [ 153 K 173 ![ 014 !!L 034 !!\ 054 , 074 < 114 !L 134 \ 154 L 174 !\ 015 !!M 035 !!] 055 - 075 = 115 !M 135 ] 155 M 175 !] 016 !!N 036 !!^ 056 . 076 > 116 !N 136 ^ 156 N 176 !^ 017 !!O 037 !!_ 057 / 077 ? 117 !O 137 _ 157 O 177 !_
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