Editing Pascal (programming language) (section)

===ISO/IEC 7185:1990 Pascal===
In 1983, the language was standardized in the international standard IEC/ISO 7185<ref>{{cite book|title=ISO/IEC 7185:1990 Pascal|url=http://www.pascal-central.com/docs/iso7185.pdf|access-date=16 September 2014|url-status=dead|archive-url=https://web.archive.org/web/20160127044422/http://pascal-central.com/docs/iso7185.pdf|archive-date=27 January 2016}}</ref> and several local country-specific standards, including the American ANSI/IEEE770X3.97-1983, and ISO 7185:1983. These two standards differed only in that the ISO standard included a "level 1" extension for conformant arrays (an array where the boundaries of the array are not known until run time), where ANSI did not allow for this extension to the original (Wirth version) language. In 1989, ISO 7185 was revised (ISO 7185:1990) to correct various errors and ambiguities found in the original document.

The ISO 7185 was stated to be a clarification of Wirth's 1974 language as detailed by the User Manual and Report [Jensen and Wirth], but was also notable for adding "Conformant Array Parameters" as a level 1 to the standard, level 0 being Pascal without conformant arrays. This addition was made at the request of [[C. A. R. Hoare]], and with the approval of Niklaus Wirth. The precipitating cause was that Hoare wanted to create a Pascal version of the [[NAG Numerical Libraries|(NAG) Numerical Algorithms Library]], which had originally been written in FORTRAN, and found that it was not possible to do so without an extension that would allow array parameters of varying size. Similar considerations motivated the inclusion in ISO 7185 of the facility to specify the parameter types of procedural and functional parameters.

Niklaus Wirth himself referred to the 1974 language as "the Standard", for example, to differentiate it from the machine specific features of the [[CDC 6000]] compiler. This language was documented in ''The Pascal Report'',<ref>{{cite book|last1=Wirth|first1=Niklaus|title=The Programming Language Pascal (Revised Report)|date=July 1973|publisher=ETH Zürich|doi=10.3929/ethz-a-000814158}}</ref> the second part of the "Pascal users manual and report".

On the large machines (mainframes and minicomputers) Pascal originated on, the standards were generally followed. On the [[IBM Personal Computer|IBM PC]], they were not. On IBM&nbsp;PCs, the Borland standards Turbo Pascal and Delphi have the greatest number of users. Thus, it is typically important to understand whether a particular implementation corresponds to the original Pascal language, or a Borland dialect of it.

The IBM&nbsp;PC versions of the language began to differ with the advent of UCSD Pascal, an interpreted implementation that featured several extensions to the language, along with several omissions and changes. Many UCSD language features survive today, including in Borland's dialect.