A68toc is a compiler that translates Algol 68 code to C code. It is an offshot of the Algol 68RS compiler project (see the Algol 68RS wikipedia entry). Available source code archives are
version 1.14: https://sourceforge.net/projects/algol68/files/algol68toc/algol68toc_1.14/
version 1.15: http://www.algol68.org/algol68toc_1.15.tar.gz
To enable a 64-bit build for a68toc some modifications had to be applied. The archive
contains the modified source. It comprises two folders: 1.) a68toc (modified compiler source code) and 2.) a68toc_test (Algol 68 sample code + Makefile).
The Algol68 source file src/modes.a68 had to be modified at one place to get the 64-bit alignment right. The C-code for memory allocation/garbage collection had been replaced with the Boehm garbage collector (hence for building a68toc resp. building programs with a68toc libgc and gc.h has to be installed with the libgc_dev package). The make setup had been modified as well:
buildtype.mk configures the debug/release and 32-bit/64-bit build of a68toc (admissible values for the variable ARCH are either 32 or 64)
a68toc might be build from the Algol 68 sources (self-compilation)
The compiler is initially build from C-sources by cd-ing into the a68toc directory and issuing
make
Once a68toc has been built from the C-sources (as a68toc/src/a68toc) it can compile itself to C code, thus by issuing
make selfcompile && make
a68toc reproduces itself.
Ctrans: portable Algol 68 compiler (on building and running a68toc)
Algol 68-R Users Guide (Algol 68-R being the predecessor of Algol 68-RS)
Informal Introduction to ALGOL 68 Revised Edition, a scan of the 1980 version of the introduction to the language by C. H. Lindsey and S. G. van der Meulen.
van Wijngaarden et. al. Revised report on the algorithmic language ALGOL 68 or this link