LLOGO: An Implementation of LOGO in LISP

Abstract

This paper describes LLOGO, an implementation of the LOGO language written in MACLISP for the ITS, TEN50 and TENEX PDP-10 systems, and MULTICS. The relative merits of LOGO and LISP as educational languages are discussed. Design decisions in the LISP implementation of LOGO are contrasted with those of two other implementations: CLOGO for the PDP-10 and 11LOGO for the PDP-11, both written in assembler language. LLOGO's special facilities for character-oriented display terminals, graphic display 'turtles', and music generation are also described.