IBM RPG - History

History

RPG is one of the few languages created for punched card machines that is still in common use today. This is because the language has evolved considerably over time. It was originally developed by IBM in 1959. The name Report Program Generator was descriptive of the purpose of the language: generation of reports from data files, including matching record and sub-total reports.

FARGO (Fourteen-o-one Automatic Report Generation Operation) was the predecessor to RPG on the IBM 1401 . Both languages were intended to facilitate ease of transition for IBM tabulating machine (Tab) unit record equipment technicians to the then new computers.

Tab machine technicians were accustomed to plugging wires into control panels to implement input, output, control and counter operations (add, subtract, multiply, divide). Tab machines programs were executed by impulses emitted in a machine cycle; hence, FARGO and RPG emulated the notion of the machine cycle with the program cycle. RPG was superior to and rapidly replaced FARGO as the report generator program of choice.

The alternative languages generally available at the time were Assembler, COBOL or FORTRAN. COBOL was a natural language-like business oriented language and FORTRAN was a language that facilitated mathematical applications. Other languages of the era included ALGOL and Autocoder and a few years later PL/I. Assembler and COBOL were more common in mainframe business operations (System/360 models 30 and above) and RPG more commonly used by customers who were in transition from tabulating equipment (System/360 model 20).