Editing Pascal (programming language) (section)

===Early compilers===
The first Pascal [[compiler]] was designed in [[Zürich]] for the [[CDC 6000 series]] [[mainframe computer]] family. [[Niklaus Wirth]] reports that a first attempt to implement it in [[Fortran|FORTRAN 66]] in 1969 was unsuccessful due to FORTRAN 66's inadequacy to express complex data structures. The second attempt was implemented in a C-like language (Scallop by Max Engeli) and then translated by hand (by R. Schild) to Pascal itself for boot-strapping.<ref>[https://www.inf.ethz.ch/personal/wirth/Miscellaneous/ComputersAndComputing.pdf Computers and Computing. A Personal Perspective.] {{webarchive|url=https://web.archive.org/web/20170510101203/https://www.inf.ethz.ch/personal/wirth/Miscellaneous/ComputersAndComputing.pdf |date=2017-05-10}} by Niklaus Wirth</ref> It was operational by mid-1970. Many Pascal compilers since have been similarly [[Self-hosting (compilers)|self-hosting]], that is, the compiler is itself written in Pascal, and the compiler is usually capable of recompiling itself when new features are added to the language, or when the compiler is to be [[porting|ported]] to a new environment. The [[GNU Pascal]] compiler is one notable exception, being written in C.

The first successful port of the CDC Pascal compiler to another mainframe was completed by Welsh and Quinn at the [[Queen's University of Belfast]] (QUB) in 1972. The target was the [[International Computers Limited]] (ICL) [[ICT 1900 series|1900 series]]. This compiler, in turn, was the parent of the Pascal compiler for the Information Computer Systems (ICS) [[Multum]] minicomputer. The Multum port was developed – with a view to using Pascal as a systems programming language – by Findlay, Cupples, Cavouras and Davis, working at the Department of Computing Science in [[Glasgow University]]. It is thought that Multum Pascal, which was completed in the summer of 1973, may have been the first [[16-bit computing|16-bit]] implementation.

A completely new compiler was completed by Welsh et al. at QUB in 1977. It offered a source-language diagnostic feature (incorporating profiling, tracing and type-aware formatted postmortem dumps) that was implemented by Findlay and Watt at Glasgow University. This implementation was ported in 1980 to the [[ICL 2900]] series by a team based at [[Southampton University]] and Glasgow University. The Standard Pascal Model Implementation was also based on this compiler, having been adapted, by Welsh and Hay at [[Manchester University]] in 1984, to check rigorously for conformity to the BSI 6192/ISO 7185 Standard and to generate code for a portable abstract machine.

The first Pascal [[compiler]] written in North America was constructed at the [[University of Illinois at Urbana–Champaign|University of Illinois]] under [[Donald B. Gillies#Later career|Donald B. Gillies]] for the [[PDP-11]] and generated native machine code.  Microsoft had Pascal compilers for IBM PCs, see [[Microsoft Pascal]].