Lisp machine
Despite being modest in number (perhaps 7,000 units total as of 1988[1]) Lisp machines commercially pioneered many now-commonplace technologies, including windowing systems, computer mice, high-resolution bit-mapped raster graphics, computer graphic rendering, laser printing, networking innovations such as Chaosnet, and effective garbage collection.
As integrated circuit technology shrank the size and cost of computers in the 1960s and early 1970s, and the memory needs of AI programs began to exceed the address space of the most common research computer, the Digital Equipment Corporation (DEC) PDP-10, researchers considered a new approach: a computer designed specifically to develop and run large artificial intelligence programs, and tailored to the semantics of the Lisp language.
[citation needed] In 1973, Richard Greenblatt and Thomas Knight, programmers at Massachusetts Institute of Technology (MIT) Artificial Intelligence Laboratory (AI Lab), began what would become the MIT Lisp Machine Project when they first began building a computer hardwired to run certain basic Lisp operations, rather than run them in software, in a 24-bit tagged architecture.
Lisp Machines ran the tests in parallel with the more conventional single instruction additions.
If the simultaneous tests failed, then the result was discarded and recomputed; this meant in many cases a speed increase by several factors.
The first group of extra bits were used to hold type data, making the machine a tagged architecture, and the remaining bits were used to implement CDR coding (wherein the usual linked list elements are compressed to occupy roughly half the space), aiding garbage collection by reportedly an order of magnitude.
It was so well received at an AI conference held at MIT in 1978 that Defense Advanced Research Projects Agency (DARPA) began funding its development.
The newfound firm was named LISP Machine, Inc. (LMI), and was funded by CDC orders, via Jacobson.
It had been hindered by Noftsker's promise to give Greenblatt a year's head start, and by severe delays in procuring venture capital.
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 Lisp Machines, Inc. sold it as the LMI-CADR.
Both firms developed second-generation products based on the CADR: the Symbolics 3600 and the LMI-LAMBDA (of which LMI managed to sell ~200).
Starting in 1987, several machines based on the Ivory processor were developed: boards for Suns and Macs, stand-alone workstations and even embedded systems (I-Machine Custom LSI, 32 bit address, Symbolics XL-400, UX-400, MacIvory II; in 1989 available platforms were Symbolics XL-1200, MacIvory III, UX-1200, Zora, NXP1000 "pizza box").
Texas Instruments shrank the Explorer into silicon as the MicroExplorer which was offered as a card for the Apple Mac II.
The Symbolics Lisp Machines were also sold to some non-AI markets like computer graphics, modeling, and animation.
Bolt, Beranek and Newman (BBN) developed its own Lisp machine, named Jericho,[8] which ran a version of Interlisp.
[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.
[20] In France, two Lisp Machine projects arose: M3L[21] at Toulouse Paul Sabatier University and later MAIA.
[23][24][25][26] With the onset of the AI winter and the early beginnings of the microcomputer revolution, which would sweep away the minicomputer and workstation makers, cheaper desktop PCs soon could run Lisp programs even faster than Lisp machines, with no use of special purpose hardware.
Their high profit margin hardware business eliminated, most Lisp machine makers had gone out of business by the early 90s, leaving only software based firms like Lucid Inc. or hardware makers who had switched to software and services to avoid the crash.
[40] Domains using the Lisp machines were mostly in the wide field of artificial intelligence applications, but also in computer graphics, medical image processing, and many others.
The disassembled machine code for above function (for the Ivory microprocessor from Symbolics): The operating system used virtual memory to provide a large address space.
