History of the IBM RPG programming language

January 2, 2011

History of the IBM RPG programming language

So, as an RPG* Developer I am definitely biased towards IBM’s best and most versatile language. IBM RPG has evolved massively from the early Report Program Generator that it was designed to be. The latest Incarnation of RPG is a leading edge web -savvy object oriented SOA language.

  • 1960’s(this is a decade of code evoloution): RPG was introduced but called something else.  Programmers started the decade wearing sharp 1950’s style suits and ended it wearing tie-dyes and Greenpeace badges.
  • 1970’s: RPG II was introduced with the System/3 series of computers. It was later used on System/32, System/34, and System/38 and then the System 36 (!), with an improved version of the language. RPG2 was a beautiful language using a logic cycle, arrays and data structures and internal file layouts. Complex, hard to master and quirky… but strangely addictive.
  • 1984: RPG III was created for the System/38 and its successor the AS/400 . RPG III significantly departed from the original language, providing modern structured constructs like IF-ENDIF blocks, DO loops, and subroutines. The is the true building block for the modern RPG language structure.
  • 1990: RPG/400 with a much cleaner syntax, and tighter integration with the integrated database. This language became the mainstay of development on the AS/400, and its editor was a simple line editor with prompt templates for each specification (type of instruction). I cant believe how many programmers, even today, still write in RPG400 ignoring all the fantastic code enhancements in later versions. It proves that RPG400 is robust but come on…
  • 1994: RPG IV  (aka RPGLE aka RPG/ILE) was released in. RPG IV offered a greater variety of expressions within its new Extended Factor-2 Calculation Specification. All older RPG3 and RPG400 code could be upgraded to RPG IV and still looked more spaced out with the step up to longer 10 character field names.