PDP-6 LISP Input-Output for the Display

Abstract

An intermediate level language for display programming has been embedded in LISP 1.5 The language is intended as a basis for higher analysis of display information. Through the construction of a hierarchy of LISP functions it will be possible to assign a complicated meaning to a series of simple light pen motions, or to construct a complex picture. The intermediate level of language should abstract from the light pen trajectory the information which these LISP functions require and provide basis for time, and programming effort. The first section of this memo discusses the system and gives programming examples. The details of the examples can be understood by reading the second section which discusses the implementation and the LISP functions available.