EBCDIC

Definitions

1. Extended Binary Coded Decimal Interchange Code, an 8-bit character encoding that IBM introduced with the System/360 mainframe in the early 1960s. It evolved from the binary coded decimal codes used on punched cards, which explains its unusual layout: the letters are not contiguous but split into groups with gaps between i and j and between r and s, so code that assumes the alphabet is a continuous range, such as checking c >= 'a' && c <= 'z', misbehaves. EBCDIC is incompatible with ASCII, which appeared at around the same time and became the standard almost everywhere else, and it exists in many national variants, known as code pages, such as CP037 and CP1047. It remains in daily use on IBM Z mainframes and IBM i systems, so data moving between mainframes and other systems must be converted, which is a persistent source of corrupted characters, mangled packed-decimal fields, and file-transfer bugs, such as those from FTP's ASCII mode translating binary data.

   In plain English: IBM's old way of turning letters into numbers for mainframe computers — different from the ASCII standard everyone else uses, and still haunting banks today.

   Example: "The bank's COBOL system sends data in EBCDIC, so our integration layer has to convert everything to UTF-8."

Related Terms

• COBOL
• Common Block
• Copybook
• JCL
• Working Storage
• Brownfield
• Base64
• Unicode
• UTF-8
• Character Set