Lisp machine

In 1979, Russell Noftsker, being convinced that Lisp machines had a bright commercial future due to the strength of the Lisp language and the enabling factor of hardware acceleration, proposed to Greenblatt that they commercialize the technology.^{[citation needed]} In a counter-intuitive move for an AI Lab hacker, Greenblatt acquiesced, hoping perhaps that he could recreate the informal and productive atmosphere of the Lab in a real business. These ideas and goals were considerably different from those of Noftsker. The two negotiated at length, but neither would compromise. As the proposed firm could succeed only with the full and undivided assistance of the AI Lab hackers as a group, Noftsker and Greenblatt decided that the fate of the enterprise was up to them, and so the choice should be left to the hackers.

The ensuing discussions of the choice divided the lab into two factions. In February 1979, matters came to a head. The hackers sided with Noftsker, believing that a commercial venture-fund-backed firm had a better chance of surviving and commercializing Lisp machines than Greenblatt's proposed self-sustaining start-up. Greenblatt lost the battle.

It was at this juncture that Symbolics, Noftsker's enterprise, slowly came together. While Noftsker was paying his staff a salary, he had no building or any equipment for the hackers to work on. He bargained with Patrick Winston that, in exchange for allowing Symbolics' staff to keep working out of MIT, Symbolics would let MIT use internally and freely all the software Symbolics developed. A consultant from CDC, who was trying to put together a natural language computer application with a group of West-coast programmers, came to Greenblatt, seeking a Lisp machine for his group to work with, about eight months after the disastrous conference with Noftsker. Greenblatt had decided to start his own rival Lisp machine firm, but he had done nothing. The consultant, Alexander Jacobson, decided that the only way Greenblatt was going to start the firm and build the Lisp machines that Jacobson desperately needed was if Jacobson pushed and otherwise helped Greenblatt launch the firm. Jacobson pulled together business plans, a board, a partner for Greenblatt (one F. Stephen Wyle). The newfound firm was named LISP Machine, Inc. (LMI), and was funded by CDC orders, via Jacobson.

Around this time Symbolics (Noftsker's firm) began operating. It had been hindered by Noftsker's promise to give Greenblatt a year's head start, and by severe delays in procuring venture capital. Symbolics still had the major advantage that while 3 or 4 of the AI Lab hackers had gone to work for Greenblatt, 14 other hackers had signed onto Symbolics. Two AI Lab people were not hired by either: Richard Stallman and Marvin Minsky. Stallman, however, blamed Symbolics for the decline of the hacker community that had centered around the AI lab. For two years, from 1982 to the end of 1983, Stallman worked by himself to clone the output of the Symbolics programmers, with the aim of preventing them from gaining a monopoly on the lab's computers.^[4]

Regardless, after a series of internal battles, Symbolics did get off the ground in 1980/1981, selling the CADR as the LM-2, while

These machines had hardware support for various primitive Lisp operations (data type testing, CDR coding) and also hardware support for incremental garbage collection. They ran large Lisp programs very efficiently. The Symbolics machine was competitive against many commercial super minicomputers, but was never adapted for conventional purposes. The Symbolics Lisp Machines were also sold to some non-AI markets like computer graphics, modeling, and animation.

The MIT-derived Lisp machines ran a Lisp dialect named

In the mid-1980s, Integrated Inference Machines (IIM) built prototypes of Lisp machines named Inferstar.[11]

In 1984–85 a UK firm, Racal-Norsk, a joint subsidiary of Racal and Norsk Data, attempted to repurpose Norsk Data's ND-500 supermini as a microcoded Lisp machine, running CADR software: the Knowledge Processing System (KPS).^[12]

There were several attempts by Japanese manufacturers to enter the Lisp machine market: the Fujitsu Facom-alpha^[13] mainframe co-processor, NTT's Elis,^[14][15] Toshiba's AI processor (AIP)^[16] and NEC's LIME.^[17] Several university research efforts produced working prototypes, among them are Kobe University's TAKITAC-7,^[18] RIKEN's FLATS,^[19] and Osaka University's EVLIS.^[20]

In France, two Lisp Machine projects arose: M3L^[21] at Toulouse Paul Sabatier University and later MAIA.^[22]

In Germany Siemens designed the RISC-based Lisp co-processor COLIBRI.^{[23][24][25][26]}

With the onset of the

(defun example-count (predicate list)
  (let ((count 0))
    (dolist (i list count)
      (when (funcall predicate i)
        (incf count)))))

Command: (disassemble (compile #'example-count))

  0  ENTRY: 2 REQUIRED, 0 OPTIONAL      ;Creating PREDICATE and LIST
  2  PUSH 0                             ;Creating COUNT
  3  PUSH FP|3                          ;LIST
  4  PUSH NIL                           ;Creating I
  5  BRANCH 15
  6  SET-TO-CDR-PUSH-CAR FP|5
  7  SET-SP-TO-ADDRESS-SAVE-TOS SP|-1
 10  START-CALL FP|2                    ;PREDICATE
 11  PUSH FP|6                          ;I
 12  FINISH-CALL-1-VALUE
 13  BRANCH-FALSE 15
 14  INCREMENT FP|4                     ;COUNT
 15  ENDP FP|5
 16  BRANCH-FALSE 6
 17  SET-SP-TO-ADDRESS SP|-2
 20  RETURN-SINGLE-STACK