Editing GPSS (section)

==History==
GPSS was developed in the 1960s by [[Geoffrey Gordon (computer scientist)|Geoffrey Gordon]], an employee of IBM's Advanced Systems Development Division (ASDD). This division was heavily involved with research into the design of teleprocessing systems, trying to achieve an economic balance of the use of computer resources and shared lines between server terminals. The simulation system, then known as the Gordon Simulator, became very popular in the study of teleprocessing systems within ASDD. It subsequently was fixed and documented on October 25, 1960 in an internal IBM memorandum.<ref>{{cite book |doi=10.1145/800025.1198386 |quote=In developing GPSS there was no conscious effort to base the design on analog computers, but I feel sure the block diagram notation and the emphasis on making the simulation directly accessible to system analysts rather than through programmers, that are characteristics of GPSS, were unconsciously influenced by the analog computer experience. |chapter=The development of the General Purpose Simulation System (GPSS) |title=History of programming languages |date=1978 |last1=Gordon |first1=Geoffrey |pages=403–426 |isbn=0-12-745040-8 }}</ref> Between the winter and summer of 1961, a group of three programmers (including Gordon) rewrote the simulation system with a new algorithm and new block types. It was officially released as a supported IBM-label program on September 27, 1961 with 25 block types. At this point, Gordon stopped working on the simulation system.

In 1963, GPSS II was released with 32 block types. It introduced system numerical attributes, which allowed tracking the current content of a ''Storage'', the length of a ''Queue'', or the current clock time.

In 1965, GPSS III was released. It was made available for IBM Systems [[IBM 7090|7090/94]] and [[IBM 7040|7040/44]].

In 1967, GPSS/360 was released to run on the newly released [[IBM System/360|System 360]].

In 1970, GPSS V was released with 49 block types.

In the 1980s, GPSS/VAC and GPSS/PC were released. These appear to be the last official IBM-label releases before the language became unlicensed.<ref name="Schriber Introduction to GPSS">{{cite conference |first1=Thomas J |last1=Schriber |date=1984 |title=Introduction to GPSS |conference=Proceedings of the 16th conference on Winter simulation (WSC '84) |publisher=IEEE Press |pages=12–15 |isbn=978-0-911801-04-0 |url=https://dl.acm.org/doi/10.5555/800013.809426 }}</ref>

Subsequently, there were releases for [[IBM 360]],<ref>(GPSS/360, on MFT/MVT but not DOS)</ref> [[Univac 1108]], and CDC.<ref>{{cite journal |title=Technical Note |journal=IEEE Transactions on Systems Science and Cybernetics
|author=D. C. Div 
|volume=4
|issue=4
|pages=446–447
|quote=IBM has available GPSS III for the 7044 and 7090 series and GPSS/360 for the larger 360 ... GPSS II has also been available on the UNIVAC 1108
|date=1968 |doi=10.1109/TSSC.1968.300174
}}</ref>
<ref name="Schriber Introduction to GPSS"/>
<ref>{{cite book |doi=10.1016/B978-0-12-745040-7.50013-2 |chapter=GPSS Session |title=History of Programming Languages |date=1981 |last1=Liskov |first1=Barbara |last2=Gordon |first2=Geoffrey |pages=403–437 |isbn=978-0-12-745040-7 }}</ref>

Over time, other implementations were developed for systems including [[Digital Equipment Corporation|DEC]]'s VAX, a specialized [[APL (programming language)|APL]] version for large-scale Univac systems,<ref>{{cite book 
|title=Current Issues in Computer Simulation |page=25
|url=https://books.google.com/books?isbn=1483258033  |isbn=978-1483258034
|author1=Nabil R. Adam  |author2=Ali Dogramaci |date=2014
|publisher=Academic Press
|quote=GPSS-like ... in the APL version of GPSS, although APL happens to be an interpretive language. ... Univac Corporation, GPSS 1100 for UNIVAC 1108 system.}}</ref> and [[Macintosh]].<ref>{{cite book |title=Introduction to Simulation With Gpss on the Pc, MacIntosh and Vax 
|isbn=0-1348-323-10|last1=Ståhl|first1=Ingolf|year=1990|publisher=Prentice Hall }}</ref>

In 2001, the [[Microsoft Windows|Windows]] program GPSS World<ref>{{Cite web |title=GPSS World REFERENCE MANUAL |url=https://athena.ecs.csus.edu/~mitchell/csc148/gpssW/Reference%20Manual/rpreface.htm |access-date=2023-12-11 |website=athena.ecs.csus.edu}}</ref> was released with new features to GPSS. It includes scripting with PLUS (a [[Pascal (programming language)|Pascal]]-like language), graphical system state displays, graphing, and optimization experiments.

In 2009, a graphical [[Java (programming language)|Java]]-based tool called JGPSS (Java General Purpose Simulation System) was developed to teach the GPSS simulation language.<ref name="J.GPSS">{{cite web |author=P. Fonseca Casas |date=2009 |title=jgpss, an open source gpss framework to teach simulation |url=http://www.informs-sim.org/wsc09papers/022.pdf |quote=simplify the development of a complete simulation tool following the GPSS syntax. This paper presents ... In the original, GPSS meant Gordon's Programmable Simulation System, in honor of Geoffrey Gordon, its creator.}}</ref><ref>{{cite web 
|title=Java General Purpose Simulation System.
|url=https://jgpss.liam.upc.edu/en
|quote=Learn simulation building a simulation engine. JGPSS is an implementation of the GPSS system based in Java.}}</ref>