ALGOL 68C

The language was originally called Z70 and was subsequently morphed into ALGOL 68. ALGOL68C was initially built to develop and program the CAMbridge ALgebra system a.k.a. CAMAL. The initial compiler was written in PSYCO (the Princeton SYntax COmpiler by Edgar T. Irons) that was implemented by J.H. Mathewman at Cambridge. The compiler and language were initially developed by Stephen Bourne and Michael Guy as a dialect of ALGOL 68.

""Algol68C"" was later used for the CHAOS OS for the CAP capability computer at Cambridge University in 1971. Other early contributors were Andrew D. Birrell and Ian Walker.

Subsequent work was done on the compiler after Bourne left Cambridge University in 1975. Garbage collection was added, and the code base is still running on an emulated OS/MVT using Hercules.

The ALGOL68C compiler generated ZCODE output, that could then be either compiled into the local machine code by a ZCODE translator or run interpreted. ZCODE is a register-based intermediate language. This ability to interpret or compile ZCODE encouraged the porting of ALGOL 68C to numerous different computer platforms. Aside from the CAP capability computer the compiler was ported to systems including CMS, TOPS-10, and Z80.

A very early predecessor of this compiler was used by Guy and Bourne to write the first Game of Life programs on the PDP-7 with a DEC 340 display (see Scientific American article) "For long-lived populations such as this one Conway sometimes uses a PDP-7 computer with a screen on which he can observe the changes; The program was written by M. J. T. Guy and S. R. Bourne. Without its help some discoveries about the game would have been difficult to make." Scientific American 223 (October 1970): 120-123.