*Lisp

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The *Lisp (StarLisp) programming language was conceived of in 1985 by Cliff Lasser and Steve Omohundro (employees of the Thinking Machines Corporation) as a way of providing an efficient yet high-level language for programming the nascent Connection Machine.

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[edit] History

[edit] Prelude

At the time the Connection Machine was being designed and built, the only language being actively developed for it was an Assembly-level language known as PARIS (Parallel Instruction Set). It became evident that a better way to program the machine was needed and needed quickly. Waiting for the completion of CM Lisp, or "Connection Machine Lisp" (an implementation of the very high-level programming language Lisp with parallel programming extensions) was not an option. CM Lisp had been proposed by Danny Hillis, and development was expected to continue for several more years.

[edit] Development

A *Lisp interpreter was initially developed. It quickly became apparent that a *Lisp compiler, translating *Lisp into Lisp and PARIS, would be needed to attain the gigaflop speeds that were theoretically attainable by a Connection Machine. The *Lisp compiler was written by Jeff Mincy and was first released in 1986. (An application achieving more than two gigaflops, a helicopter wake simulator, was developed by Alan Egolf, then an employee of United Technologies, and J. P. Massar, a Thinking Machines employee, in 1987; see "Helicopter Free Wake Implementation On Advanced Computer Architectures", International Conference on Basic Rotorcraft Research, 1988)

A *Lisp Simulator, an emulator meant to run *Lisp code on standard, non-parallel machines, was developed at the same time by JP Massar. This simulator still exists [1], and was ported to ANSI Common Lisp in 2001. An older version written in the original Common Lisp, exists in the Carnegie Mellon University AI Archives [2].

Later versions of *Lisp, involving significant upgrades to its functionality and performance, were worked on by Cliff Lasser, Jeff Mincy and J. P. Massar through 1989.

StarLisp was implemented on the Thinking Machines CM5 circa 1990-1991 by J. P. Massar and Mario Bourgoin.

[edit] Implementation

StarLisp was essentially a set of macros written on top of Common Lisp, and therefore had the full power of Common Lisp behind it. To use a Connection Machine, one needed a host or 'front-end'. To use *Lisp, that front-end had to run Common Lisp. Symbolics' machines using Genera OS and Sun Microsystems workstations running Lucid Inc.'s Lucid Common Lisp were both used for *Lisp.

StarLisp operated on PVARS (Parallel Variables). PVARS represented Connection Machine memory, and were essentially vectors: one element per CM processor (or virtual processor).

StarLisp consisted of standard operations on PVARS, like vector addition and multiplication, along with communications primitives that essentially reordered the elements of a PVAR using the CM's communications hardware to optimally route the data.