[2-20] What is a "Lisp Machine" (LISPM)?

A Lisp machine (or LISPM) is a computer which has been optimized to run lisp
efficiently and provide a good environment for programming in it. The
original Lisp machines were implemented at MIT, with spinoffs as LMI (defunct)
and Symbolics (bankrupt). Xerox also had a series of Lisp machines
(Dandylion, Dandytiger), as did Texas Instruments (TI Explorer). The
TI and Symbolics Lisp machines are currently available as cards that
fit into Macintosh computers (the so-called "Lisp on a chip").

Optimizations typical of Lisp machines include:

   - Hardware Type Checking. Special type bits let the type be checked
     efficiently at run-time.

   - Hardware Garbage Collection. 

   - Fast Function Calls. 

   - Efficient Representation of Lists.

   - System Software and Integrated Programming Environments.

For further information, see:

   Paul Graham, "Anatomy of a Lisp Machine", AI Expert, December 1988.

   Pleszkun and Thazhuthaveetil, "The Architecture of Lisp Machines",
   IEEE Computer, March 1987.

   Ditzel, Schuler and Thomas, "A Lisp Machine Profile: Symbolics 3650",
   AI Expert, January 1987.

   Peter M. Kogge, "The Architecture of Symbolic Computers",
   McGraw-Hill 1991. ISBN 0-07-035596-7.

[Derived from a post by Arthur Pendragon <apendragon@delphi.com>.]