ALGOL 68C is an imperative computer programming language, a dialect of ALGOL 68, that was developed by Stephen R. Bourne and Michael Guy to program the Cambridge Algebra System (CAMAL). The initial compiler was written in the Princeton Syntax Compiler (PSYCO,<!-- Do not link to Python JIT compiler. --> by Edgar T. Irons) that was implemented by J. H. Mathewman at Cambridge.

ALGOL 68C was later used for the CHAOS OS<!-- Do not link to Linux distribution. --> for the capability-based security CAP computer at University of Cambridge 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 ALGOL 68C compiler generated output in ZCODE, a register-based intermediate language, which could then be either interpreted or compiled to a native executable. This ability to interpret or compile ZCODE encouraged the porting of ALGOL 68C to many different computing platforms. Aside from the CAP computer, the compiler was ported to systems including Conversational Monitor System (CMS), TOPS-10, and Zilog Z80.

ALGOL 68C extensions to ALGOL 68

Below is a sampling of some notable extensions:

NAME

adb - debugger

SYNOPSIS

adb [-w] [ objfil [ corfil ] ]

[...]

COMMANDS

[...]

$modifier

Miscellaneous commands. The available modifiers

are:

[...]

a ALGOL 68 stack backtrace. If address is

given then it is taken to be the address of

the current frame (instead of r4). If count

is given then only the first count frames

are printed.

References

</references>

  • Cambridge ALGOL 68: on the historical roster of computer languages – includes 10+ publication references.
  • A Transportation of ALGOL 68C – PJ Gardner, University of Essex – March 1977 (From 370 to DECsystem-10)
  • Running ALGOL 68C on MVS - how to install ALGOL 68C on an emulated MVS system