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Revision as of 21:04, 21 February 2019 edit 99Electrons (talk \| contribs) Extended confirmed users 1,897 edits removed Category:IBM; added Category:IBM computer hardware using HotCat ← Previous edit		Latest revision as of 15:58, 31 March 2025 edit undo Neiltonks (talk \| contribs) Extended confirmed users, Pending changes reviewers 20,287 edits Importing Wikidata short description: "IBM 6-bit data transmission code" Tag: Shortdesc helper
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Line 1: {{Short description\|IBM 6-bit data transmission code}} {{Other uses\|Transcode (disambiguation)}} {{Use dmy dates\|date=May 2019\|cs1-dates=y}} '''Transcode''', or ''Transmission Code'', is a no longer used 6-bit plus parity [[BCD (6-bit)\|BCD]] [[character encoding\|character set]] which was used by [[IBM]] for a short time for [[Binary Synchronous Communications\|Binary Synchronous communications]]. The [[IBM 2780]] data transmission terminal was announced with Transcode support in 1967. The [[IBM 2780#3780\|IBM 3780]] data communication terminal, the 2780 successor announced in 1972, dropped Transcode support. '''Six-Bit Transcode''', or '''Six-Bit Transmission Code''', was, for a few years, one of the three [[character encoding\|character sets]] used by [[IBM]] for [[Binary Synchronous Communications]]. Transmission using 6-bit Transcode had higher throughput than transmission using 8-bit EBCDIC or ASCII, provided that the data to be transmitted used a limited set of 48 characters. The [[IBM 2780]] data transmission terminal was announced with Transcode support in 1967. Its successor, the [[IBM 2780#3780\|IBM 3780]] [[data communication]] terminal, announced in 1972, dropped Transcode support and added a "space compression" option. Transcode was a 64 character set including twenty-six upper case alphabetic characters, ten numerics, thirteen special characters, and sixteen [[control characters]]. Characters were transmitted with [[odd parity]].<ref>{{cite book\|last=IBM Corporation \|title=Component Description: IBM 2780 Communications Terminal \|year=1971 \|url=http://computer-refuge.org/bitsavers/pdf/ibm/27xx/GA27-3005-3-2780_Data_Terminal_Description_Aug71.pdf \|deadurl=yes \|archiveurl=https://web.archive.org/web/20110929024649/http://computer-refuge.org/bitsavers/pdf/ibm/27xx/GA27-3005-3-2780_Data_Terminal_Description_Aug71.pdf \|archivedate=September 29, 2011 }}</ref> Transcode is a [[six-bit character code]]. It relates to IBM's [[punched card code]] but, like [[EBCDIC]], it is not [[BCD (character encoding)\|BCD]]. Its 64 values consist of the 26 uppercase letters, 10 numbers, 11 symbols, [[space (character)\|space]], and 16 [[control character]]s. Its 48 printable characters are <code>ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 .'-/@#$%&⌑</code>; it cannot represent <code>,:;!?"()[]<>+^=_\`{}\|~</code>. Characters are transmitted with [[odd parity]]. The 2780 cannot use the 16 control characters as data characters in Transcode mode.<ref>{{cite book \|last=IBM Corporation \|title=Component Description: IBM 2780 Communications Terminal \|year=1971 \|url=http://www.bitsavers.org/pdf/ibm/2780/GA27-3005-3-2780_Data_Terminal_Description_Aug71.pdf \|url-status=live \|archive-url=https://web.archive.org/web/20200726231256/http://www.bitsavers.org/pdf/ibm/2780/GA27-3005-3-2780_Data_Terminal_Description_Aug71.pdf \|archive-date=2020-07-26}}</ref> ==Code table== {\|{{chset-table-header1\|Six-Bit Transcode}} \|- \|{{chset-left1\|0x}} \|{{chset-ctrl1\|U+0001 START OF HEADING\|{{Control code link\|SOH}}}} \|{{chset-cell1\|U+0041 LATIN CAPITAL LETTER A\|[[A]]\|1}} \|{{chset-cell1\|U+0042 LATIN CAPITAL LETTER B\|[[B]]\|2}} \|{{chset-cell1\|U+0043 LATIN CAPITAL LETTER C\|[[C]]\|3}} \|{{chset-cell1\|U+0044 LATIN CAPITAL LETTER D\|[[D]]\|4}} \|{{chset-cell1\|U+0045 LATIN CAPITAL LETTER E\|[[E]]\|5}} \|{{chset-cell1\|U+0046 LATIN CAPITAL LETTER F\|[[F]]\|6}} \|{{chset-cell1\|U+0047 LATIN CAPITAL LETTER G\|[[G]]\|7}} \|{{chset-cell1\|U+0048 LATIN CAPITAL LETTER H\|[[H]]\|8}} \|{{chset-cell1\|U+0049 LATIN CAPITAL LETTER I\|[[I]]\|9}} \|{{chset-ctrl1\|U+0002 START OF TEXT\|{{Control code link\|STX}}}} \|{{chset-cell1\|U+002E FULL STOP\|[[Full stop\|.]]}} \|{{chset-cell1\|U+2311 SQUARE LOZENGE\|[[Lozenge (shape)\|⌑]]}} \|{{chset-ctrl1\|U+0007 BELL\|{{Control code link\|BEL}}}} \|{{chset-ctrl1\|U+001A SUBSTITUTE\|{{Control code link\|SUB}}}} \|{{chset-ctrl1\|U+0017 END OF TRANSMISSION BLOCK\|{{Control code link\|ETB}}}} \|- \|{{chset-left1\|1x}} \|{{chset-cell1\|U+0026 AMPERSAND\|[[Ampersand\|&]]}} \|{{chset-cell1\|U+004A LATIN CAPITAL LETTER J\|[[J]]}} \|{{chset-cell1\|U+004B LATIN CAPITAL LETTER K\|[[K]]}} \|{{chset-cell1\|U+004C LATIN CAPITAL LETTER L\|[[L]]}} \|{{chset-cell1\|U+004D LATIN CAPITAL LETTER M\|[[M]]}} \|{{chset-cell1\|U+004E LATIN CAPITAL LETTER N\|[[N]]}} \|{{chset-cell1\|U+004F LATIN CAPITAL LETTER O\|[[O]]}} \|{{chset-cell1\|U+0050 LATIN CAPITAL LETTER P\|[[P]]}} \|{{chset-cell1\|U+0051 LATIN CAPITAL LETTER Q\|[[Q]]}} \|{{chset-cell1\|U+0052 LATIN CAPITAL LETTER R\|[[R]]}} \|{{chset-ctrl1\|U+0020 SPACE\|[[Space character\|SP]]}} \|{{chset-cell1\|U+0024 DOLLAR SIGN\|[[Dollar sign\|$]]}} \|{{chset-cell1\|U+002A ASTERISK\|[[Asterisk\|]]}} \|{{chset-ctrl1\|U+001F INFORMATION SEPARATOR ONE\|{{Control code link\|US\|IUS}}/<br/>{{Control code link\|IUS/ITB\|ITB}}\|style=line-height:1}} \|{{chset-ctrl1\|U+0004 END OF TRANSMISSION\|{{Control code link\|EOT}}}} \|{{chset-ctrl1\|U+0010 DATA LINK ESCAPE\|{{Control code link\|DLE}}}} \|- \|{{chset-left1\|2x}} \|{{chset-cell1\|U+002D HYPHEN-MINUS\|[[Hyphen-minus\|-]]}} \|{{chset-cell1\|U+002F SOLIDUS\|[[Slash (punctuation)\|/]]}} \|{{chset-cell1\|U+0053 LATIN CAPITAL LETTER S\|[[S]]}} \|{{chset-cell1\|U+0054 LATIN CAPITAL LETTER T\|[[T]]}} \|{{chset-cell1\|U+0055 LATIN CAPITAL LETTER U\|[[U]]}} \|{{chset-cell1\|U+0056 LATIN CAPITAL LETTER V\|[[V]]}} \|{{chset-cell1\|U+0057 LATIN CAPITAL LETTER W\|[[W]]}} \|{{chset-cell1\|U+0058 LATIN CAPITAL LETTER X\|[[X]]}} \|{{chset-cell1\|U+0059 LATIN CAPITAL LETTER Y\|[[Y]]}} \|{{chset-cell1\|U+005A LATIN CAPITAL LETTER Z\|[[Z]]}} \|{{chset-ctrl1\|U+001B ESCAPE\|{{Control code link\|ESC}}}} \|{{chset-cell1\|U+0027 APOSTROPHE\|[[Apostrophe\|']]}} \|{{chset-cell1\|U+0025 PERCENT SIGN\|[[Percent sign\|%]]}} \|{{chset-ctrl1\|U+0005 ENQUIRY\|{{Control code link\|ENQ}}}} \|{{chset-ctrl1\|U+0003 END OF TEXT\|{{Control code link\|ETX}}}} \|{{chset-ctrl1\|U+0009 CHARACTER TABULATION\|{{Control code link\|HT}}}} \|- \|{{chset-left1\|3x}} \|{{chset-cell1\|U+0030 DIGIT ZERO\|[[0]]}} \|{{chset-cell1\|U+0031 DIGIT ONE\|[[1]]}} \|{{chset-cell1\|U+0032 DIGIT TWO\|[[2]]}} \|{{chset-cell1\|U+0033 DIGIT THREE\|[[3]]}} \|{{chset-cell1\|U+0034 DIGIT FOUR\|[[4]]}} \|{{chset-cell1\|U+0035 DIGIT FIVE\|[[5]]}} \|{{chset-cell1\|U+0036 DIGIT SIX\|[[6]]}} \|{{chset-cell1\|U+0037 DIGIT SEVEN\|[[7]]}} \|{{chset-cell1\|U+0038 DIGIT EIGHT\|[[8]]}} \|{{chset-cell1\|U+0039 DIGIT NINE\|[[9]]}} \|{{chset-ctrl1\|U+0016 SYNCHRONOUS IDLE\|{{Control code link\|SYN}}}} \|{{chset-cell1\|U+0023 NUMBER SIGN\|[[Number sign\|#]]}} \|{{chset-cell1\|U+0040 COMMERCIAL AT\|[[At sign\|@]]}} \|{{chset-ctrl1\|U+0015 NEGATIVE ACKNOWLEDGE\|{{Control code link\|NAK}}}} \|{{chset-ctrl1\|U+0019 END OF MEDIUM\|{{Control code link\|EM }}}} \|{{chset-ctrl1\|U+007F DELETE\|{{Control code link\|DEL}}}} \|} ==Code table (from 2780 manual)== {\| class="wikitable" style="font-family: 'Courier New';" ! Character<br>  !! [[Punched card]]<br>code !! 6-bit<br>transcode !! Hex  Line 27 ⟶ 109: \| I \|\| 12-9 \|\|      2     5 P \|\| 09 \|- \| STX \|\| 12-09-2 \|\|      2   4   P \|\| 0A \|- \| . \|\| 12-98-3 \|\|      2   4 5   \|\| 0B \|- \| ~~⌑~~⌑ \|\| 12-98-4 \|\|      2 3     P \|\| 0C \|- \| BEL \|\| 0-9-8-7 \|\|      2 3   5   \|\| 0D Line 37 ⟶ 119: \| Sub \|\| 9-8-7 \|\|      2 3 4     \|\| 0E \|- \| ETB \|\| 90-89-6 \|\|      2 3 4 5 P \|\| 0F \|- \| & \|\| 12 \|\|    1           \|\| 10 Line 91 ⟶ 173: \| Z \|\| 0-9 \|\|  0   2     5   \|\| 29 \|- \| ESC \|\| 90-89-7 \|\|  0   2   4     \|\| 2A \|- \| ' \|\| 0-8-3 \|\|  0   2   4 5 P \|\| 2B \|- \| ~~%~~% \|\| 0-8-4 \|\|  0   2 3       \|\| 2C \|- \| ENQ \|\| 0-9-8-5 \|\|  0   2 3   5 P \|\| 2D Line 137 ⟶ 219: ==Devices using Transcode== * [[IBM 2701]] Data Adapter Unit. * [[IBM 2703]] Transmission Control. * [[IBM 2780/3780\|IBM 2780]] Data Transmission Terminal. * [[IBM System/370]] model 135 Integrated Communications Adapter (ICA). ==References== {{Reflist}} {{~~character~~Character ~~encoding~~encodings}} [[Category:Character encoding]]