ALGOL 68RS - History

History

Although the ALGOL 68R compiler written by I.F. Currie, J.D. Morrison and S.G. Bond was a great success it suffered from two major problems—it had been written for the nearly obsolete ICL 1900 computer and it implemented an out-of-date version of the language as it was released before the Revised Report on ALGOL 68 was available.

RSRE needed a newer compiler for various internal projects so the team of Currie and Morrison wrote a new compiler designed for machine independence. The compiler itself dealt with the parsing of ALGOL 68, producing a high level intermediate language known as stream language that would then be compiled to machine code by a translator. The compiler only needed to know the sizes of the various object machine types and the character set available.

The compiler was written in ALGOL 68, bootstrapped initially using the ALGOL 68R compiler.

A team of two programmers at Oxford University Computing Services wrote a code generator for the ICL 2900 series. Martyn Thomas of SWURCC arranged that this system be sponsored by ICL and sold as an official ICL product.

Later the Avon Universities Joint Computer Centre, a large user of MULTICS requested the SWURCC team to produce a MULTICS version of ALGOL 68RS. A version for the DEC VAX computer was also written.

Eventually the team at SWURCC formed a company Praxis, initially supporting the MULTICS version of ALGOL 68RS.

RSRE also used the ALGOL 68RS compiler for internal projects, including the Flex machine and the ELLA hardware design language. When it was decided to make ELLA freely available Praxis was commissioned to write an ALGOL 68 to C translator, ctrans, based on the ALGOL 68RS compiler.