ALGOL 68S is a
programming language
A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language.
The description of a programming l ...
designed as a subset of
ALGOL 68
ALGOL 68 (short for ''Algorithmic Language 1968'') is an imperative programming language that was conceived as a successor to the ALGOL 60 programming language, designed with the goal of a much wider scope of application and more rigorously ...
, to allow compiling via a
one-pass compiler.
It was mostly for
numerical analysis
Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics). It is the study of numerical methods th ...
.
Implementations
A compiler for ALGOL 68S was available for the
PDP-11
The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation (DEC) from 1970 into the 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of all models were so ...
, written in the language
BLISS. The multiprocessor version designed for the
C.mmp[ Description of C.mmp A68S implementation.] has been preserved at the PDP Unix Preservation Society archive.
created another implementation of ALGOL 68, named ALGOL 68S, for
Sun-3, Sun
SPARC
SPARC (Scalable Processor Architecture) is a reduced instruction set computer (RISC) instruction set architecture originally developed by Sun Microsystems. Its design was strongly influenced by the experimental Berkeley RISC system developed ...
(under
SunOS
SunOS is a Unix-branded operating system developed by Sun Microsystems for their workstation and server computer systems. The ''SunOS'' name is usually only used to refer to versions 1.0 to 4.1.4, which were based on BSD, while versions 5.0 ...
4.1), Sun SPARC (under
Solaris 2),
Atari ST (under
GEMDOS
GEM (for Graphics Environment Manager) is an operating environment released by Digital Research (DRI) in 1985 for use with the DOS operating system on Intel 8088 and Motorola 68000 microprocessors.
GEM is known primarily as the graphical user i ...
) and
Acorn Archimedes
Acorn Archimedes is a family of personal computers designed by Acorn Computers of Cambridge, England. The systems are based on Acorn's own ARM architecture processors and the proprietary operating systems Arthur and RISC OS. The first models ...
(under
RISC OS
RISC OS is a computer operating system originally designed by Acorn Computers Ltd in Cambridge, England. First released in 1987, it was designed to run on the ARM chipset, which Acorn had designed concurrently for use in its new line of Archi ...
), c.f
Charles Lindsey's Home Page
Chief differences from ALGOL 68
The main differences between ALGOL 68 and 68S, as summarised from Appendix 4 of the Informal Introduction,
include:
* No ''union''
* No ''flex'', but ''string''s are handled specially
* No arrays inside structures (but references to arrays were allowed) and a similar restriction on arrays of arrays (multidimensional arrays are nonetheless permitted)
* Limits on use of ''long'' and ''short'' to aid implementing on small computers
* No ''heap''
* No
parallel processing
* Limits on the order of declaration and other small syntactic differences to allow one-pass compiling
* No ''format''s
References
Subset
In mathematics, set ''A'' is a subset of a set ''B'' if all elements of ''A'' are also elements of ''B''; ''B'' is then a superset of ''A''. It is possible for ''A'' and ''B'' to be equal; if they are unequal, then ''A'' is a proper subset o ...
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