Other six-bit encodings with completely different mappings, such as some FIELDATA[1] variants or Transcode, are sometimes incorrectly termed BCD.
Among the vendors using BCD were Burroughs,[5] Bull, CDC,[6] IBM, General Electric (the computer division was purchased by Honeywell in 1969), NCR, Siemens, and Sperry-UNIVAC.
The closest Unicode equivalent is U+29E7 ⧧ THERMODYNAMIC, but that is not found in many fonts, so U+2021 ‡ DOUBLE DAGGER is often used instead.
The groupmark was proposed for Unicode standardization in 2015,[9] and was assigned to value U+2BD2 ⯒ GROUP MARK.
There are three major categories of difference: In "Spanish speaking countries", the character "Ñ" did not exist in the original system, therefore "@" was chosen by most manufacturers: Bull, NCR, and Control Data, but there was an inconsistency when merging databases to 7-bit ASCII code, for in that coding system the "/" character was chosen, resulting in two different codes for the same character.
The following charts show the numeric values of BCD characters in hexadecimal (base-16) notation, as that most clearly reflects the structure of 4-bit binary coded decimal, plus two extra bits.
This was based on a 40-character punched card code; the original 37 (10 digits, 26 letters, and blank), plus three commercially important characters added around 1932:[1]: 67 hyphen-minus used for printing credit balances and hyphenated names, the ampersand also used in many names and addresses (Procter & Gamble, Mr. & Mrs. Smith), and the asterisk used to overprint unused fields when printing cheques.
The IBM 704 reordered the BCDIC code to allow a normal alphabetic collating order internally, with 0 before 1 and A before Z.
It could automatically translate between this internal form and the earlier BCDIC when reading and writing magnetic tapes.
[13]: 35 (+0 and −0 were rarely used characters that corresponded to the punched-card convention of a digit 0 with an overpunched sign in rows 12 or 11.)
The following table shows the code assignments for the type 716 printer used starting with the IBM 704 computer and through the 7094.
There was some variation; IBM 704 Fortran had a different set of special characters (preserving only the duplicated minus sign).