FACOM270-20上へのLISPの実現

The implementation of LISP for FACOM 270-20(main memory 16 k words, drum area 131 k words) is described.
LISP language is unfit for the computer with a small main memory because of requiring a large free storage space. In the present system, the specifications of LISP 1.5 were made alterations in order to save the consumption of the main memory and improve an execution time as follows :
(1) A push down stack instead of a-list is used for the binding mechainsm of variables, and the virtualization of its stack is performed.
(2) The atom-headers are placed on the array which is token jointly with a hash table.
(3) A interger is represented by making use of the addresses other than the main memory.