Lisp is a programming language famous for its use in Artificial Intelligence and advanced Computer Science research. First developed in 1958, it is the second oldest (after Fortran) high-level programming language still in common use.

Two dialects of Lisp are available at TWENEX.ORG, Maclisp and InterLisp-10.

(@MACLISP)

Maclisp was developed in the mid-1960's as part of MIT's Project MAC¹⁾, originally for the PDP-6 ITS operating system.

Maclisp was a highly influential language and was the primary inspiration for Common Lisp, with contributions form other dialects like InterLisp.

Before running MACLISP, you must define the following logical name:

@DEFINE MACLISP: PS:<MACLISP>

(You can add the above line to your LOGIN.CMD file to automatically define the logical name for all of you TWENEX sessions.)

It is also recommended that you create a Maclisp init file (LISP.INI) in your home directory with the following contents:

;;; A very typical init file / Emacs mode--> -*- Mode:LISP; -*-
(COMMENT) ;magic
(PROGN ; real init file stuff
  (SETQ BASE 10. IBASE 10. *NOPRINT NIL) ;base-10 display
  (SETQ NOUUO T *RSET T) ;these make debugging easier
  (SSTATUS FEATURE NOLDMSG) ;supress module load messages
  '*) ;return an asterisk for Maclisp to print out

LEDIT is a software package that allows a programmer to inspect, modify, and save Lisp source expressions from within a Maclisp session, abilities Maclisp itself lacks. This is achieved by calling the Emacs editor from the programmer's Maclisp session.

To use LEDIT:

1. Start Maclisp and load your source file.
2. Evaluate (LOAD “LISP:LEDIT.FASL”) (You may add this line to your LISP.INI file and eliminate this step.)
3. Evaluate (LEDIT) to switch to Emacs.
4. Load the source file into Emacs (^X ^F).
5. View, change, save source with Emacs commands.
6. Flag function definitions to update in Maclisp with M-Z.
7. Return to Maclisp with ^X Z.

K.M. Pitman. (2007, December 16). The Revised Maclisp Manual [Online]. Available: http://www.maclisp.info/pitmanual