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CDC display code#6/12 display code

{{Short description|Computer 6-bit character code}}

Display code is the six-bit character code used by many computer systems manufactured by Control Data Corporation, notably the CDC 6000 series in 1964, the 7600 in 1967 and the following Cyber series in 1971. The CDC 6000 series and their successors had 60 bit words. As such, typical usage packed 10 characters per word. It is a six-bit extension of the four-bit BCD encoding, and was referred to as BCDIC{{cn|date=March 2021}} (BCD interchange code.)

Overview

There were several variations of display code, notably the 63-character character set, and the 64-character character set. There were also 'CDC graphic' and 'ASCII graphic' variants of both the 63- and 64-character sets. The choice between 63- or 64-character character set, and between CDC or ASCII graphic was site-selectable. Generally, early CDC customers started out with the 63-character character set, and CDC graphic print trains on their line printers. As time-sharing became prevalent, almost all sites used the ASCII variant - so that line printer output would match interactive usage. Later CDC customers were also more likely to use the 64-character character set.

A later variation, called 6/12 display code, was used in the Kronos and NOS timesharing systems in order to support full ASCII capabilities. In 6/12 mode, an escape character (the circumflex, octal 76) would indicate that the following letter was lower case. Thus, upper case and other characters were 6 bits in length, and lower case characters were 12 bits in length.

The PLATO system used a further variant of 6/12 display code. Noting that lower case letters were most common in typical PLATO usage, the roles were reversed. Lower case letters were the norm, and the escape character preceded upper case letters.

The typical text file format used a zero-byte terminator to signify the end of each record. The zero-byte terminator was indicated by, at least, the final twelve bits of a 60-bit word being set to zero.CDC often used the term byte to refer to 12-bit quantities, even though characters were only 6-bits long. The terminator could actually be anywhere from 12- to 66-bits long - depending on the length of the record. This caused an ambiguity in the 64-character character set, when a colon character needed to be the final character in a record. In such cases a blank character was typically appended to the record after the trailing colon.

Display code characters

=64-character character set version=

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ASCIICDC
BinaryDecimalOctalGraphicGraphicName
000 000000::colonDisplay code 00 has no associated graphic in the 63-character set
000 001101AA
000 010202BB
000 011303CC
000 100404DD
000 101505EE
000 110606FF
000 111707GG
001 000810HH
001 001911II
001 0101012JJ
001 0111113KK
001 1001214LL
001 1011315MM
001 1101416NN
001 1111517OO
010 0001620PP
010 0011721QQ
010 0101822RR
010 0111923SS
010 1002024TT
010 1012125UU
010 1102226VV
010 1112327WW
011 0002430XX
011 0012531YY
011 0102632ZZ
011 011273300
011 100283411
011 101293522
011 110303633
011 111313744

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ASCIICDC
BinaryDecimalOctalGraphicGraphicName
100 000324055
100 001334166
100 010344277
100 011354388
100 100364499
100 1013745++
100 1103846--
100 1113947**
101 0004050//
101 0014151((
101 0104252))
101 0114353$$
101 1004454==
101 1014555  blank
101 1104656,,
101 1114757..
110 0004860#≡equiv
110 0014961[[
110 0105062]]
110 0115163%%Display code 63 (octal) is a : (colon) in the 63-character set
110 1005264"≠not eq
110 1015365_→concatIn CDC PASCAL, this is the left brace, {, character
110 1105466!∨log OR
110 1115567&∧log AND
111 0005670'↑super
111 0015771?↓subIn CDC PASCAL, this is the right brace, }, character
111 0105872<<
111 0115973>>
111 1006074@≤
111 1016175\≥
111 1106276^¬NOT
111 1116377;;

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=6/12 display code=

The NOS 6/12 display code is one of the character sets used on CDC Cyber NOS computers to represent all ASCII characters.

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colspan="3"| ASCIIcolspan="3"| display code
DecHexAbbrDecOct6/12
style="background:#CFF;"| 0style="background:lightblue;"| 00NULstyle="background:#CFF;"| 62 32style="background:lightblue;"| 76 40^5
style="background:#CFF;"| 1style="background:lightblue;"| 01SOHstyle="background:#CFF;"| 62 33style="background:lightblue;"| 76 41^6
style="background:#CFF;"| 2style="background:lightblue;"| 02STXstyle="background:#CFF;"| 62 34style="background:lightblue;"| 76 42^7
style="background:#CFF;"| 3style="background:lightblue;"| 03ETXstyle="background:#CFF;"| 62 35style="background:lightblue;"| 76 43^8
style="background:#CFF;"| 4style="background:lightblue;"| 04EOTstyle="background:#CFF;"| 62 36style="background:lightblue;"| 76 44^9
style="background:#CFF;"| 5style="background:lightblue;"| 05ENQstyle="background:#CFF;"| 62 37style="background:lightblue;"| 76 45^+
style="background:#CFF;"| 6style="background:lightblue;"| 06ACKstyle="background:#CFF;"| 62 38style="background:lightblue;"| 76 46^-
style="background:#CFF;"| 7style="background:lightblue;"| 07BELstyle="background:#CFF;"| 62 39style="background:lightblue;"| 76 47^*
style="background:#CFF;"| 8style="background:lightblue;"| 08BSstyle="background:#CFF;"| 62 40style="background:lightblue;"| 76 50^/
style="background:#CFF;"| 9style="background:lightblue;"| 09HTstyle="background:#CFF;"| 62 41style="background:lightblue;"| 76 51^(
style="background:#CFF;"| 10style="background:lightblue;"| 0ALFstyle="background:#CFF;"| 62 42style="background:lightblue;"| 76 52^)
style="background:#CFF;"| 11style="background:lightblue;"| 0BVTstyle="background:#CFF;"| 62 43style="background:lightblue;"| 76 53^$
style="background:#CFF;"| 12style="background:lightblue;"| 0CFFstyle="background:#CFF;"| 62 44style="background:lightblue;"| 76 54^=
style="background:#CFF;"| 13style="background:lightblue;"| 0DCRstyle="background:#CFF;"| 62 45style="background:lightblue;"| 76 55^ 
style="background:#CFF;"| 14style="background:lightblue;"| 0ESOstyle="background:#CFF;"| 62 46style="background:lightblue;"| 76 56^,
style="background:#CFF;"| 15style="background:lightblue;"| 0FSIstyle="background:#CFF;"| 62 47style="background:lightblue;"| 76 57^.
style="background:#CFF;"| 16style="background:lightblue;"| 10DLEstyle="background:#CFF;"| 62 48style="background:lightblue;"| 76 60^#
style="background:#CFF;"| 17style="background:lightblue;"| 11DC1style="background:#CFF;"| 62 49style="background:lightblue;"| 76 61^[
style="background:#CFF;"| 18style="background:lightblue;"| 12DC2style="background:#CFF;"| 62 50style="background:lightblue;"| 76 62^]
style="background:#CFF;"| 19style="background:lightblue;"| 13DC3style="background:#CFF;"| 62 51style="background:lightblue;"| 76 63^%
style="background:#CFF;"| 20style="background:lightblue;"| 14DC4style="background:#CFF;"| 62 52style="background:lightblue;"| 76 64^"
style="background:#CFF;"| 21style="background:lightblue;"| 15NAKstyle="background:#CFF;"| 62 53style="background:lightblue;"| 76 65^_
style="background:#CFF;"| 22style="background:lightblue;"| 16SYNstyle="background:#CFF;"| 62 54style="background:lightblue;"| 76 66^!
style="background:#CFF;"| 23style="background:lightblue;"| 17ETBstyle="background:#CFF;"| 62 55style="background:lightblue;"| 76 67^&
style="background:#CFF;"| 24style="background:lightblue;"| 18CANstyle="background:#CFF;"| 62 56style="background:lightblue;"| 76 70^'
style="background:#CFF;"| 25style="background:lightblue;"| 19EMstyle="background:#CFF;"| 62 57style="background:lightblue;"| 76 71^?
style="background:#CFF;"| 26style="background:lightblue;"| 1ASUBstyle="background:#CFF;"| 62 58style="background:lightblue;"| 76 72^<
style="background:#CFF;"| 27style="background:lightblue;"| 1BESCstyle="background:#CFF;"| 62 59style="background:lightblue;"| 76 73^>
style="background:#CFF;"| 28style="background:lightblue;"| 1CFSstyle="background:#CFF;"| 62 60style="background:lightblue;"| 76 74^@
style="background:#CFF;"| 29style="background:lightblue;"| 1DGSstyle="background:#CFF;"| 62 61style="background:lightblue;"| 76 75^\
style="background:#CFF;"| 30style="background:lightblue;"| 1ERSstyle="background:#CFF;"| 62 62style="background:lightblue;"| 76 76^^
style="background:#CFF;"| 31style="background:lightblue;"| 1FUSstyle="background:#CFF;"| 62 63style="background:lightblue;"| 76 77^;

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! colspan="3"| ASCII !! colspan="3"| display code

DecHexGlyphDecOct6/12
style="background:#cff;"| 32style="background:lightblue;"| 20style="background:#CFF;"| 45style="background:lightblue;"| 55
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| style="background:#cff;"| 33

style="background:lightblue;"| 21!style="background:#CFF;"| 54style="background:lightblue;"| 66!
style="background:#cff;"| 34style="background:lightblue;"| 22"style="background:#CFF;"| 52style="background:lightblue;"| 64"
style="background:#cff;"| 35style="background:lightblue;"| 23#style="background:#CFF;"| 48style="background:lightblue;"| 60#
style="background:#cff;"| 36style="background:lightblue;"| 24$style="background:#CFF;"| 43style="background:lightblue;"| 53$
style="background:#cff;"| 37style="background:lightblue;"| 25%style="background:#CFF;"| 51style="background:lightblue;"| 63%
style="background:#cff;"| 38style="background:lightblue;"| 26&style="background:#CFF;"| 55style="background:lightblue;"| 67&
style="background:#cff;"| 39style="background:lightblue;"| 27'style="background:#CFF;"| 56style="background:lightblue;"| 70'
style="background:#cff;"| 40style="background:lightblue;"| 28(style="background:#CFF;"| 41style="background:lightblue;"| 51(
style="background:#cff;"| 41style="background:lightblue;"| 29)style="background:#CFF;"| 42style="background:lightblue;"| 52)
style="background:#cff;"| 42style="background:lightblue;"| 2A*style="background:#CFF;"| 39style="background:lightblue;"| 47*
style="background:#cff;"| 43style="background:lightblue;"| 2B+style="background:#CFF;"| 37style="background:lightblue;"| 45+
style="background:#cff;"| 44style="background:lightblue;"| 2C,style="background:#CFF;"| 46style="background:lightblue;"| 56,
style="background:#cff;"| 45style="background:lightblue;"| 2DHyphen-minus
style="background:#CFF;"| 38style="background:lightblue;"| 46-
style="background:#cff;"| 46style="background:lightblue;"| 2E.style="background:#CFF;"| 47style="background:lightblue;"| 57.
style="background:#cff;"| 47style="background:lightblue;"| 2F/style="background:#CFF;"| 40style="background:lightblue;"| 50/
style="background:#cff;"| 48style="background:lightblue;"| 300style="background:#CFF;"| 27style="background:lightblue;"| 330
style="background:#cff;"| 49style="background:lightblue;"| 311style="background:#CFF;"| 28style="background:lightblue;"| 341
style="background:#cff;"| 50style="background:lightblue;"| 322style="background:#CFF;"| 29style="background:lightblue;"| 352
style="background:#cff;"| 51style="background:lightblue;"| 333style="background:#CFF;"| 30style="background:lightblue;"| 363
style="background:#cff;"| 52style="background:lightblue;"| 344style="background:#CFF;"| 31style="background:lightblue;"| 374
style="background:#cff;"| 53style="background:lightblue;"| 355style="background:#CFF;"| 32style="background:lightblue;"| 405
style="background:#cff;"| 54style="background:lightblue;"| 366style="background:#CFF;"| 33style="background:lightblue;"| 416
style="background:#cff;"| 55style="background:lightblue;"| 377style="background:#CFF;"| 34style="background:lightblue;"| 427
style="background:#cff;"| 56style="background:lightblue;"| 388style="background:#CFF;"| 35style="background:lightblue;"| 438
style="background:#cff;"| 57style="background:lightblue;"| 399style="background:#CFF;"| 36style="background:lightblue;"| 449
style="background:#cff;"| 58style="background:lightblue;"| 3A:style="background:#CFF;"| 60 4style="background:lightblue;"| 74 04@D
style="background:#cff;"| 59style="background:lightblue;"| 3B;style="background:#CFF;"| 63style="background:lightblue;"| 77;
style="background:#cff;"| 60style="background:lightblue;"| 3C<style="background:#CFF;"| 58style="background:lightblue;"| 72<
style="background:#cff;"| 61style="background:lightblue;"| 3D=style="background:#CFF;"| 44style="background:lightblue;"| 54=
style="background:#cff;"| 62style="background:lightblue;"| 3E>style="background:#CFF;"| 59style="background:lightblue;"| 73>
style="background:#cff;"| 63style="background:lightblue;"| 3F?style="background:#CFF;"| 57style="background:lightblue;"| 71?

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{| class="wikitable" style="text-align: center;"

colspan="3"| ASCIIcolspan="3"| display code
DecHexGlyphDecOct6/12
style="background:#cff;"| 64style="background:lightblue;"| 40@style="background:#CFF;"| 60 1style="background:lightblue;"| 74 01@A
style="background:#cff;"| 65style="background:lightblue;"| 41Astyle="background:#CFF;"| 1style="background:lightblue;"| 01A
style="background:#cff;"| 66style="background:lightblue;"| 42Bstyle="background:#CFF;"| 2style="background:lightblue;"| 02B
style="background:#cff;"| 67style="background:lightblue;"| 43Cstyle="background:#CFF;"| 3style="background:lightblue;"| 03C
style="background:#cff;"| 68style="background:lightblue;"| 44Dstyle="background:#CFF;"| 4style="background:lightblue;"| 04D
style="background:#cff;"| 69style="background:lightblue;"| 45Estyle="background:#CFF;"| 5style="background:lightblue;"| 05E
style="background:#cff;"| 70style="background:lightblue;"| 46Fstyle="background:#CFF;"| 6style="background:lightblue;"| 06F
style="background:#cff;"| 71style="background:lightblue;"| 47Gstyle="background:#CFF;"| 7style="background:lightblue;"| 07G
style="background:#cff;"| 72style="background:lightblue;"| 48Hstyle="background:#CFF;"| 8style="background:lightblue;"| 10H
style="background:#cff;"| 73style="background:lightblue;"| 49Istyle="background:#CFF;"| 9style="background:lightblue;"| 11I
style="background:#cff;"| 74style="background:lightblue;"| 4AJstyle="background:#CFF;"| 10style="background:lightblue;"| 12J
style="background:#cff;"| 75style="background:lightblue;"| 4BKstyle="background:#CFF;"| 11style="background:lightblue;"| 13K
style="background:#cff;"| 76style="background:lightblue;"| 4CLstyle="background:#CFF;"| 12style="background:lightblue;"| 14L
style="background:#cff;"| 77style="background:lightblue;"| 4DMstyle="background:#CFF;"| 13style="background:lightblue;"| 15M
style="background:#cff;"| 78style="background:lightblue;"| 4ENstyle="background:#CFF;"| 14style="background:lightblue;"| 16N
style="background:#cff;"| 79style="background:lightblue;"| 4FOstyle="background:#CFF;"| 15style="background:lightblue;"| 17O
style="background:#cff;"| 80style="background:lightblue;"| 50Pstyle="background:#CFF;"| 16style="background:lightblue;"| 20P
style="background:#cff;"| 81style="background:lightblue;"| 51Qstyle="background:#CFF;"| 17style="background:lightblue;"| 21Q
style="background:#cff;"| 82style="background:lightblue;"| 52Rstyle="background:#CFF;"| 18style="background:lightblue;"| 22R
style="background:#cff;"| 83style="background:lightblue;"| 53Sstyle="background:#CFF;"| 19style="background:lightblue;"| 23S
style="background:#cff;"| 84style="background:lightblue;"| 54Tstyle="background:#CFF;"| 20style="background:lightblue;"| 24T
style="background:#cff;"| 85style="background:lightblue;"| 55Ustyle="background:#CFF;"| 21style="background:lightblue;"| 25U
style="background:#cff;"| 86style="background:lightblue;"| 56Vstyle="background:#CFF;"| 22style="background:lightblue;"| 26V
style="background:#cff;"| 87style="background:lightblue;"| 57Wstyle="background:#CFF;"| 23style="background:lightblue;"| 27W
style="background:#cff;"| 88style="background:lightblue;"| 58Xstyle="background:#CFF;"| 24style="background:lightblue;"| 30X
style="background:#cff;"| 89style="background:lightblue;"| 59Ystyle="background:#CFF;"| 25style="background:lightblue;"| 31Y
style="background:#cff;"| 90style="background:lightblue;"| 5AZstyle="background:#CFF;"| 26style="background:lightblue;"| 32Z
style="background:#cff;"| 91style="background:lightblue;"| 5B[style="background:#CFF;"| 49style="background:lightblue;"| 61[
style="background:#cff;"| 92style="background:lightblue;"| 5C\style="background:#CFF;"| 61style="background:lightblue;"| 75\
style="background:#cff;"| 93style="background:lightblue;"| 5D]style="background:#CFF;"| 50style="background:lightblue;"| 62]
style="background:#cff;"| 94style="background:lightblue;"| 5E^style="background:#CFF;"| 60 2style="background:lightblue;"| 74 02@B
style="background:#cff;"| 95style="background:lightblue;"| 5F_style="background:#CFF;"| 53style="background:lightblue;"| 65_

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! colspan="3"| ASCII !! colspan="3"| display code

DecHexGlyphDecOct6/12
style="background:#cff;"| 96style="background:lightblue;"| 60'style="background:#CFF;"| 60 7style="background:lightblue;"| 74 07@G
style="background:#cff;"| 97style="background:lightblue;"| 61astyle="background:#CFF;"| 62 1style="background:lightblue;"| 76 01^A
style="background:#cff;"| 98style="background:lightblue;"| 62bstyle="background:#CFF;"| 62 2style="background:lightblue;"| 76 02^B
style="background:#cff;"| 99style="background:lightblue;"| 63cstyle="background:#CFF;"| 62 3style="background:lightblue;"| 76 03^C
style="background:#cff;"| 100style="background:lightblue;"| 64dstyle="background:#CFF;"| 62 4style="background:lightblue;"| 76 04^D
style="background:#cff;"| 101style="background:lightblue;"| 65estyle="background:#CFF;"| 62 5style="background:lightblue;"| 76 05^E
style="background:#cff;"| 102style="background:lightblue;"| 66fstyle="background:#CFF;"| 62 6style="background:lightblue;"| 76 06^F
style="background:#cff;"| 103style="background:lightblue;"| 67gstyle="background:#CFF;"| 62 7style="background:lightblue;"| 76 07^G
style="background:#cff;"| 104style="background:lightblue;"| 68hstyle="background:#CFF;"| 62 8style="background:lightblue;"| 76 10^H
style="background:#cff;"| 105style="background:lightblue;"| 69istyle="background:#CFF;"| 62 9style="background:lightblue;"| 76 11^I
style="background:#cff;"| 106style="background:lightblue;"| 6Ajstyle="background:#CFF;"| 62 10style="background:lightblue;"| 76 12^J
style="background:#cff;"| 107style="background:lightblue;"| 6Bkstyle="background:#CFF;"| 62 11style="background:lightblue;"| 76 13^K
style="background:#cff;"| 108style="background:lightblue;"| 6Clstyle="background:#CFF;"| 62 12style="background:lightblue;"| 76 14^L
style="background:#cff;"| 109style="background:lightblue;"| 6Dmstyle="background:#CFF;"| 62 13style="background:lightblue;"| 76 15^M
style="background:#cff;"| 110style="background:lightblue;"| 6Enstyle="background:#CFF;"| 62 14style="background:lightblue;"| 76 16^N
style="background:#cff;"| 111style="background:lightblue;"| 6Fostyle="background:#CFF;"| 62 15style="background:lightblue;"| 76 17^O
style="background:#cff;"| 112style="background:lightblue;"| 70pstyle="background:#CFF;"| 62 16style="background:lightblue;"| 76 20^P
style="background:#cff;"| 113style="background:lightblue;"| 71qstyle="background:#CFF;"| 62 17style="background:lightblue;"| 76 21^Q
style="background:#cff;"| 114style="background:lightblue;"| 72rstyle="background:#CFF;"| 62 18style="background:lightblue;"| 76 22^R
style="background:#cff;"| 115style="background:lightblue;"| 73sstyle="background:#CFF;"| 62 19style="background:lightblue;"| 76 23^S
style="background:#cff;"| 116style="background:lightblue;"| 74tstyle="background:#CFF;"| 62 20style="background:lightblue;"| 76 24^T
style="background:#cff;"| 117style="background:lightblue;"| 75ustyle="background:#CFF;"| 62 21style="background:lightblue;"| 76 25^U
style="background:#cff;"| 118style="background:lightblue;"| 76vstyle="background:#CFF;"| 62 22style="background:lightblue;"| 76 26^V
style="background:#cff;"| 119style="background:lightblue;"| 77wstyle="background:#CFF;"| 62 23style="background:lightblue;"| 76 27^W
style="background:#cff;"| 120style="background:lightblue;"| 78xstyle="background:#CFF;"| 62 24style="background:lightblue;"| 76 30^X
style="background:#cff;"| 121style="background:lightblue;"| 79ystyle="background:#CFF;"| 62 25style="background:lightblue;"| 76 31^Y
style="background:#cff;"| 122style="background:lightblue;"| 7Azstyle="background:#CFF;"| 62 26style="background:lightblue;"| 76 32^Z
style="background:#cff;"| 123style="background:lightblue;"| 7B{style="background:#CFF;"| 62 27style="background:lightblue;"| 76 33^0
style="background:#cff;"| 124style="background:lightblue;"| 7C{{pipe}}style="background:#CFF;"| 62 28style="background:lightblue;"| 76 34^1
style="background:#cff;"| 125style="background:lightblue;"| 7DBracket#Curly brackets
||style="background:#CFF;"| 62 29 ||style="background:lightblue;"| 76 35 || ^2

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| style="background:#cff;"| 126 ||style="background:lightblue;"| 7E || ~ ||style="background:#CFF;"| 62 30 ||style="background:lightblue;"| 76 36 || ^3

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| style="background:#CFF;"| 127 ||style="background:lightblue;"| 7F || DEL ||style="background:#CFF;"| 62 31 ||style="background:lightblue;"| 76 37 || ^4

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External links

  • {{cite web |title=Computer Arithmetic |at=The Early Days of Hexadecimal |author-first=John J. G. |author-last=Savard |date=2018 |orig-year=2005 |work=quadibloc |url=http://www.quadibloc.com/comp/cp02.htm |access-date=2018-07-16 |url-status=live |archive-url=https://web.archive.org/web/20180716102439/http://www.quadibloc.com/comp/cp02.htm |archive-date=2018-07-16}}
  • {{cite web |title=Charsets for CDC machines |url=http://www.informatik.uni-hamburg.de/RZ/software/gnu/utilities/recode_9.html |author=Francois Pinard |date=1999-04-27 |url-status=dead |archive-url=https://web.archive.org/web/20110623004850/http://www.informatik.uni-hamburg.de/RZ/software/gnu/utilities/recode_9.html |archive-date=2011-06-23}}

{{Control Data Corporation}}

{{Character encodings}}

Category:Character sets

Category:Control Data Corporation software