Lisp Machines, Inc. was a company formed in 1979 by Richard Greenblatt of MIT 's Artificial Intelligence Laboratory to build Lisp machines . It was based in Cambridge, Massachusetts .
85-555: By 1979, the Lisp Machine Project at MIT, originated and headed by Greenblatt, had constructed over 30 CADR computers for various projects at MIT. Russell Noftsker , who had formerly been administrator of the MIT Artificial Intelligence lab some years previously and who had since started and run a small company, was convinced that computers based on the artificial intelligence language LISP had
170-476: A trade secret . Software can be made available with fewer restrictions on licensing or source-code access; software that satisfies certain conditions of freedom and openness is known as " free " or " open-source ." Since license agreements do not override applicable copyright law or contract law , provisions in conflict with applicable law are not enforceable. Some software is specifically licensed and not sold, in order to avoid limitations of copyright such as
255-507: A "mixed source" model including both free and non-free software in the same distribution. Most if not all so-called proprietary UNIX distributions are mixed source software, bundling open-source components like BIND , Sendmail , X Window System , DHCP , and others along with a purely proprietary kernel and system utilities. Some free software packages are also simultaneously available under proprietary terms. Examples include MySQL , Sendmail and ssh. The original copyright holders for
340-645: A 1989 Canadian political scandal which, as a side-effect, resulted in the seizure of all the assets of GigaMos, rendering the company unable to meet payroll. According to Richard Stallman, the dispute between LMI and Symbolics inspired Stallman to start software development for the GNU operating system in January 1984, and the Free Software Foundation (FSF) in October 1985. These were forerunners of
425-415: A 24-bit tagged architecture . The machine also did incremental (or Arena ) garbage collection . More specifically, since Lisp variables are typed at runtime rather than compile time, a simple addition of two variables could take five times as long on conventional hardware, due to test and branch instructions. Lisp Machines ran the tests in parallel with the more conventional single instruction additions. If
510-468: A February 21, 1997, internal Microsoft memo drafted for Bill Gates : Early versions of the iPhone SDK were covered by a non-disclosure agreement . The agreement forbade independent developers from discussing the content of the interfaces. Apple discontinued the NDA in October 2008. Any dependency on the future versions and upgrades for a proprietary software package can create vendor lock-in , entrenching
595-467: A Government Security Program (GSP) to allow governments to view source code and Microsoft security documentation, of which the Chinese government was an early participant. The program is part of Microsoft's broader Shared Source Initiative which provides source code access for some products. The Reference Source License (Ms-RSL) and Limited Public License (Ms-LPL) are proprietary software licenses where
680-917: 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). There were several attempts by Japanese manufacturers to enter the Lisp machine market: the Fujitsu Facom-alpha mainframe co-processor, NTT's Elis, Toshiba's AI processor (AIP) and NEC's LIME. Several university research efforts produced working prototypes, among them are Kobe University's TAKITAC-7, RIKEN's FLATS, and Osaka University's EVLIS. In France, two Lisp Machine projects arose: M3L at Toulouse Paul Sabatier University and later MAIA. In Germany Siemens designed
765-543: A board, and a partner, F. Stephen Wyle, for Greenblatt. The newfound company was named LISP Machine, Inc. (LMI), and was funded mostly by order flow including CDC orders, via Jacobson. The following parable-like story is told about LMI by Steven Levy and used for the first time in Hackers: Heroes of the Computer Revolution (1984). Levy's account of hackers is in large part based on the values of
850-548: 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. 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
935-446: A bright future commercially. There were a number of ready customers who were anxious to get machines similar to ones they had seen at MIT. Greenblatt and Noftsker had differing ideas about the structure and financing of the proposed company. Greenblatt believed the company could be "bootstrapped", i.e. financed practically from scratch from the order flow from customers (some of whom were willing to pay in advance). This would mean that
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#17327915924381020-550: 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
1105-401: A copy can decide whether, and how much, to charge for a copy or related services. Proprietary software that comes for no cost is called freeware . Proponents of commercial proprietary software argue that requiring users to pay for software as a product increases funding or time available for the research and development of software. For example, Microsoft says that per-copy fees maximize
1190-453: A function that counts the number of elements of a list for which a predicate returns true . 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. Memory management was done with garbage collection. All code shared a single address space . All data objects were stored with
1275-564: A license for the Internet forum software vBulletin can modify the source for their own site but cannot redistribute it. This is true for many web applications, which must be in source code form when being run by a web server. The source code is covered by a non-disclosure agreement or a license that allows, for example, study and modification, but not redistribution. The text-based email client Pine and certain implementations of Secure Shell are distributed with proprietary licenses that make
1360-560: A monopoly position. Proprietary software may also have licensing terms that limit the usage of that software to a specific set of hardware. Apple has such a licensing model for macOS , an operating system which is limited to Apple hardware, both by licensing and various design decisions. This licensing model has been affirmed by the United States Court of Appeals for the Ninth Circuit . Proprietary software which
1445-612: A separate chain of events, was being developed by Western Digital Corporation. This allowed the popular LAMBDA "2x2" configuration whereby two machines shared one infrastructure, with considerable savings. Texas Instruments (TI) joined the fray by investing in LMI after it ran out of money, purchasing and relocating the NuBus engineering workstation unit from Western Digital, licensing the LMI-LAMBDA design and later producing its own variant,
1530-481: A single user or computer. In some cases, software features are restricted during or after the trial period, a practice sometimes called crippleware . Proprietary software often stores some of its data in file formats that are incompatible with other software, and may also communicate using protocols which are incompatible. Such formats and protocols may be restricted as trade secrets or subject to patents . A proprietary application programming interface (API)
1615-462: A software package may be ended to force users to upgrade and pay for newer versions ( planned obsolescence ). Sometimes another vendor or a software's community themselves can provide support for the software, or the users can migrate to either competing systems with longer support life cycles or to FOSS -based systems. Some proprietary software is released by their owner at end-of-life as open-source or source available software, often to prevent
1700-492: A tag in memory, so that the type could be determined at runtime. Multiple execution threads were supported and termed processes . All processes ran in the one address space. All operating system software was written in Lisp. Xerox used Interlisp. Symbolics, LMI, and TI used Lisp Machine Lisp (descendant of MacLisp). With the appearance of Common Lisp, Common Lisp was supported on the Lisp Machines and some system software
1785-425: A technical measure, such as product activation , a product key or serial number, a hardware key , or copy protection . Vendors may also distribute versions that remove particular features, or versions which allow only certain fields of endeavor, such as non-commercial, educational, or non-profit use. Use restrictions vary by license: Vendors typically distribute proprietary software in compiled form, usually
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#17327915924381870-408: A version of Interlisp . It was never marketed. Frustrated, the whole AI group resigned, and were hired mostly by Xerox. So, Xerox Palo Alto Research Center had, simultaneously with Greenblatt's own development at MIT, developed their own Lisp machines which were designed to run InterLisp (and later Common Lisp ). The same hardware was used with different software also as Smalltalk machines and as
1955-406: A work of free software, even copyleft free software, can use dual-licensing to allow themselves or others to redistribute proprietary versions. Non-copyleft free software (i.e. software distributed under a permissive free software license or released to the public domain) allows anyone to make proprietary redistributions. Free software that depends on proprietary software is considered "trapped" by
2040-529: 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, a solid 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
2125-435: Is software that grants its creator, publisher, or other rightsholder or rightsholder partner a legal monopoly by modern copyright and intellectual property law to exclude the recipient from freely sharing the software or modifying it, and—in some cases, as is the case with some patent-encumbered and EULA -bound software—from making use of the software on their own, thereby restricting their freedoms. Proprietary software
2210-484: Is a software library interface "specific to one device or, more likely to a number of devices within a particular manufacturer's product range." The motivation for using a proprietary API can be vendor lock-in or because standard APIs do not support the device's functionality. The European Commission , in its March 24, 2004, decision on Microsoft's business practices, quotes, in paragraph 463, Microsoft general manager for C++ development Aaron Contorer as stating in
2295-625: Is a subset of non-free software , a term defined in contrast to free and open-source software ; non-commercial licenses such as CC BY-NC are not deemed proprietary, but are non-free. Proprietary software may either be closed-source software or source-available software . Until the late 1960s, computers—especially large and expensive mainframe computers , machines in specially air-conditioned computer rooms—were usually leased to customers rather than sold . Service and all software available were usually supplied by manufacturers without separate charge until 1969. Computer vendors usually provided
2380-525: Is blocking the user's freedom that he believes is a "crime", not the act of charging for a copy of the software. Symbolics had recruited most of the remaining MIT hackers including notable hacker Bill Gosper, who then left the AI Lab. Symbolics forced Greenblatt to also resign at the AI lab, by citing MIT policies. So for two years at the MIT AI Lab, from 1982 to the end of 1983, Stallman singlehandedly duplicated
2465-489: Is no longer marketed, supported or sold by its owner is called abandonware , the digital form of orphaned works . If the proprietor of a software package should cease to exist, or decide to cease or limit production or support for a proprietary software package, recipients and users of the package may have no recourse if problems are found with the software. Proprietors can fail to improve and support software because of business problems. Support for older or existing versions of
2550-436: Is not synonymous with commercial software , although the two terms are sometimes used synonymously in articles about free software. Proprietary software can be distributed at no cost or for a fee, and free software can be distributed at no cost or for a fee. The difference is that whether proprietary software can be distributed, and what the fee would be, is at the proprietor's discretion. With free software, anyone who has
2635-400: Is required for another party to use the software. In the case of proprietary software with source code available, the vendor may also prohibit customers from distributing their modifications to the source code. Shareware is closed-source software whose owner encourages redistribution at no cost, but which the user sometimes must pay to use after a trial period. The fee usually allows use by
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2720-785: The TI Explorer . Symbolics continued to develop the 3600 family and its operating system, Genera , and produced the Ivory, a VLSI chip implementation of the Symbolics architecture . Texas Instruments shrunk the Explorer into silicon as the Explorer II and later the MicroExplorer. LMI abandoned the CADR architecture and developed its own K-Machine, but LMI went bankrupt in 1987 before the machine could be brought to market. LMI
2805-595: The TI Explorer . Some of the LMI-LAMBDAs and the TI Explorer were dual systems with both a Lisp and a Unix processor. TI also developed a 32-bit microprocessor version of its Lisp CPU for the TI Explorer. This Lisp chip also was used for the MicroExplorer – a NuBus board for the Apple Macintosh II (NuBus was initially developed at MIT for use in Lisp machines). Symbolics continued to develop
2890-679: The Xerox Star office system. These included the Xerox 1100, Dolphin (1979); the Xerox 1132, Dorado ; the Xerox 1108, Dandelion (1981); the Xerox 1109, Dandetiger ; and the Xerox 1186/6085 , Daybreak . The operating system of the Xerox Lisp machines has also been ported to a virtual machine and is available for several platforms as a product named Medley . The Xerox machine was well known for its advanced development environment (InterLisp-D),
2975-425: The first-sale doctrine . The owner of proprietary software exercises certain exclusive rights over the software. The owner can restrict the use, inspection of source code, modification of source code, and redistribution. Vendors typically limit the number of computers on which software can be used, and prohibit the user from installing the software on extra computers. Restricted use is sometimes enforced through
3060-430: The hackers at MIT Artificial Intelligence Laboratory. Among these hackers was Richard Stallman , whom Levy at the time called the last true hacker. The people at the lab came together, and together created a true hacker 's machine, the original Lisp Machines . When Russell Noftsker suggested that they move on, and spread the gospel beyond the walls of the lab, the hackers at the lab differed wildly in how they wanted
3145-468: The machine language understood by the computer's central processing unit . They typically retain the source code , or human-readable version of the software, often written in a higher level programming language . This scheme is often referred to as closed source. While most proprietary software is distributed without the source code, some vendors distribute the source code or otherwise make it available to customers. For example, users who have purchased
3230-860: The open-source-software movement and the Linux operating system. Lisp machine Lisp machines are general-purpose computers designed to efficiently run Lisp as their main software and programming language , usually via hardware support. They are an example of a high-level language computer architecture . In a sense, they were the first commercial single-user workstations . Despite being modest in number (perhaps 7,000 units total as of 1988 ) Lisp machines commercially pioneered many now-commonplace technologies, including effective garbage collection , laser printing , windowing systems , computer mice , high-resolution bit-mapped raster graphics , computer graphic rendering, and networking innovations such as Chaosnet . Several firms built and sold Lisp machines in
3315-538: The operating system (relatively) simple, these machines would not be shared, but would be dedicated to single users. 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
3400-547: The 1980s: Symbolics (3600, 3640, XL1200, MacIvory, and other models), Lisp Machines Incorporated (LMI Lambda), Texas Instruments ( Explorer, MicroExplorer ), and Xerox ( Interlisp -D workstations). The operating systems were written in Lisp Machine Lisp , Interlisp (Xerox), and later partly in Common Lisp . Artificial intelligence (AI) computer programs of the 1960s and 1970s intrinsically required what
3485-550: The 3600 family and its operating system, Genera , and produced the Ivory, a VLSI implementation of the Symbolics architecture. 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
Lisp Machines - Misplaced Pages Continue
3570-482: The 3600 family of Lisp machines was supposed to ship quickly, but the 3600s were repeatedly delayed, and Symbolics ended up producing ~100 LM-2s, each of which sold for $ 70,000. Both firms developed second-generation products based on the CADR: the Symbolics 3600 and the LMI-LAMBDA (of which LMI managed to sell ~200). The 3600, which shipped a year late, expanded on the CADR by widening the machine word to 36-bits, expanding
3655-555: 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. 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. Symbolics did not intend to produce many LM-2s, since
3740-461: The CADR: the Symbolics 3600 and the LMI-LAMBDA (of which LMI managed to sell around 200). The 3600, which shipped a year late, expanded on the CADR by widening the machine word to 36-bits, expanding the address space to 28-bits, and adding hardware to accelerate certain common functions that were implemented in microcode on the CADR. The LMI-LAMBDA, which came out a year after the 3600, in 1983,
3825-580: The E3 Project (TI Explorer II Emulation), Meroko (TI Explorer I), and Nevermore (TI Explorer I). On 3 October 2005, the MIT released the CADR Lisp Machine source code as open source. In September 2014, Alexander Burger, developer of PicoLisp , announced PilMCU, an implementation of PicoLisp in hardware. The Bitsavers' PDF Document Archive has PDF versions of the extensive documentation for
3910-687: The Explorer into silicon as the MicroExplorer which was offered as a card for the Apple Mac II . LMI abandoned the CADR architecture and developed its own K-Machine, but LMI went bankrupt before the machine could be brought to market. Before its demise, LMI was working on a distributed system for the LAMBDA using Moby space. 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
3995-625: The Free Software Foundation. This includes software written only for Microsoft Windows, or software that could only run on Java , before it became free software. Most of the software is covered by copyright which, along with contract law , patents , and trade secrets , provides legal basis for its owner to establish exclusive rights. A software vendor delineates the specific terms of use in an end-user license agreement (EULA). The user may agree to this contract in writing, interactively on screen ( clickwrap ), or by opening
4080-765: The LMI-CADR. After a series of internal battles, Symbolics began selling the CADR from the MIT Lab as the LM-2. Symbolics 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 none of the AI Lab hackers had gone to work for Greenblatt, a solid 14 had signed onto Symbolics. There were two AI Lab people who choose not to be employed by either: Richard Stallman and Marvin Minsky . Symbolics ended up producing around 100 LM-2s, each of which sold for $ 70,000. Both companies developed second-generation products based on
4165-462: The Lisp machines were designed as personal workstations for software development in Lisp. They were used by one person and offered no multi-user mode. The machines provided a large, black and white, bitmap display, keyboard and mouse, network adapter, local hard disks, more than 1 MB RAM, serial interfaces, and a local bus for extension cards. Color graphics cards, tape drives, and laser printers were optional. The processor did not run Lisp directly, but
4250-548: The RISC-based Lisp co-processor COLIBRI. 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
4335-522: The ROOMS window manager, for its early graphical user interface and for novel applications like NoteCards (one of the first hypertext applications). Xerox also worked on a Lisp machine based on reduced instruction set computing (RISC), using the 'Xerox Common Lisp Processor' and planned to bring it to market by 1987, which did not occur. In the mid-1980s, Integrated Inference Machines (IIM) built prototypes of Lisp machines named Inferstar. In 1984–85
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#17327915924384420-709: The Symbolics Lisp Machines, the TI Explorer and MicroExplorer Lisp Machines and the Xerox Interlisp-D Lisp Machines. 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 main commercial expert systems of the 80s were available: Intellicorp's Knowledge Engineering Environment (KEE), Knowledge Craft, from The Carnegie Group Inc., and ART ( Automated Reasoning Tool ) from Inference Corporation. Initially
4505-404: The address space to 28-bits, and adding hardware to accelerate certain common functions that were implemented in microcode on the CADR. The LMI-LAMBDA, which came out a year after the 3600, in 1983, was compatible with the CADR (it could run CADR microcode), but hardware differences existed. Texas Instruments (TI) joined the fray when it licensed the LMI-LAMBDA design and produced its own variant,
4590-416: The box containing the software ( shrink wrap licensing ). License agreements are usually not negotiable . Software patents grant exclusive rights to algorithms, software features, or other patentable subject matter , with coverage varying by jurisdiction. Vendors sometimes grant patent rights to the user in the license agreement. The source code for a piece of proprietary software is routinely handled as
4675-413: The company run. Greenblatt insisted that the company remain true to the hacker spirit, in that it should bow to no one, and focus solely on the creation of a good product. Some other hackers felt that this was not the way to lead a company. If this was done, it would never grow and truly spread the word of the hacker ethic . Furthermore, Greenblatt demanded control over the company, to ensure that his vision
4760-622: 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. As of January 2015 , besides Xerox and TI, Symbolics is the only Lisp machine firm still operating, selling the Open Genera Lisp machine software environment and the Macsyma computer algebra system. Several attempts to write open-source emulators for various Lisp Machines have been made: CADR Emulation, Symbolics L Lisp Machine Emulation,
4845-452: The efforts of the Symbolics programmers, in order to prevent them from gaining a monopoly on the lab's computers. Although LMI was able to benefit from Stallman's freely available code, he was the last of the "hackers" at the lab. Later programmers would have to sign non-disclosure agreements not to share source code or technical information with other software developers. Lisp Machines, Inc. sold its first LISP machines, designed at MIT, as
4930-404: The legal characteristics of software was triggered by the U.S. Copyright Act of 1976 ; see software copyright . While both companies delivered proprietary software , Richard Stallman believed that LMI, unlike Symbolics, had tried to avoid hurting the lab. Stallman had proclaimed that "the prospect of charging money for software was a crime against humanity." He clarified, years later, that it
5015-619: The legal status of software copyright , especially for object code , was not clear until the 1983 appeals court ruling in Apple Computer, Inc. v. Franklin Computer Corp . According to Brewster Kahle the legal characteristic of software changed also due to the U.S. Copyright Act of 1976 . Starting in February 1983 IBM adopted an " object-code -only" model for a growing list of their software and stopped shipping much of
5100-508: 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
5185-402: The principals of the company would retain control. Noftsker favored a more conventional venture capital model, raising a considerable sum of money, but with the investors having control of the company. The two negotiated at length, but neither would compromise. The ensuing discussions of the choice rent the lab into two factions. In February, 1979, matters came to a head. Greenblatt believed that
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#17327915924385270-411: The proceeds from the construction and sale of a few machines could be profitably reinvested in the funding of the company. Most sided with Noftsker, believing that a commercial venture fund-backed company had a better chance of surviving and commercializing Lisp Machines than Greenblatt's proposed self-sustaining start-up. They went on to start Symbolics Inc. Alexander Jacobson, a consultant from CDC ,
5355-403: 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
5440-523: The same architecture. About 25 of what were essentially prototype CADRs were sold within and without MIT for ~$ 50,000; it quickly became the favorite machine for hacking – many of the most favored software tools were quickly ported to it (e.g. Emacs was ported from ITS in 1975 ). 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. In 1979, Russell Noftsker , being convinced that Lisp machines had
5525-422: The simultaneous tests failed, then the result was discarded and recomputed; this meant in many cases a speed increase by several factors. This simultaneous checking approach was used as well in testing the bounds of arrays when referenced, and other memory management necessities (not merely garbage collection or arrays). Type checking was further improved and automated when the conventional byte word of 32 bits
5610-548: 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. To keep
5695-445: 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
5780-442: The software Symbolics developed. Unfortunately this openness would later lead to accusations of intellectual property theft . In the early 1980s, to prevent software from being used on their competitors' computers, manufacturers stopped distributing source code and began using copyright and restrictive software licenses to limit or prohibit copying and redistribution. Such proprietary software had existed before, but this shift in
5865-561: The software from becoming unsupported and unavailable abandonware . 3D Realms and id Software are famous for the practice of releasing closed source software into the open source . Some of those kinds are free-of-charge downloads ( freeware ), some are still commercially sold (e.g. Arx Fatalis ). More examples of formerly closed-source software in the List of commercial software with available source code and List of commercial video games with available source code . Proprietary software
5950-484: The software. This is particularly common with certain programming languages . For example, the bytecode for programs written in Java can be easily decompiled to somewhat usable code, and the source code for programs written in scripting languages such as PHP or JavaScript is available at run time . Proprietary software vendors can prohibit the users from sharing the software with others. Another unique license
6035-402: The source code available. Some licenses for proprietary software allow distributing changes to the source code, but only to others licensed for the product, and some of those modifications are eventually picked up by the vendor. Some governments fear that proprietary software may include defects or malicious features which would compromise sensitive information. In 2003 Microsoft established
6120-826: The source code for installed software to customers. Customers who developed software often made it available to the public without charge. Closed source means computer programs whose source code is not published except to licensees. It is available to be modified only by the organization that developed it and those licensed to use the software. In 1969, IBM, which had antitrust lawsuits pending against it, led an industry change by starting to charge separately for mainframe software and services, by unbundling hardware and software. Bill Gates ' " Open Letter to Hobbyists " in 1976 decried computer hobbyists' rampant copyright infringement of software, particularly Microsoft's Altair BASIC interpreter, and asserted that their unauthorized use hindered his ability to produce quality software. But
6205-476: The source code is made available . Governments have also been accused of adding such malware to software themselves. According to documents released by Edward Snowden , the NSA has used covert partnerships with software companies to make commercial encryption software exploitable to eavesdropping, or to insert backdoors . Software vendors sometimes use obfuscated code to impede users who would reverse engineer
6290-606: The source code, even to licensees. In 1983, binary software became copyrightable in the United States as well by the Apple vs. Franklin law decision, before which only source code was copyrightable. Additionally, the growing availability of millions of computers based on the same microprocessor architecture created for the first time an unfragmented and big enough market for binary distributed software. Software distributions considered as proprietary may in fact incorporate
6375-506: The space), aiding garbage collection by reportedly an order of magnitude. A further improvement was two microcode instructions which specifically supported Lisp functions , reducing the cost of calling a function to as little as 20 clock cycles, in some Symbolics implementations. The first machine was called the CONS machine (named after the list construction operator cons in Lisp). Often it
6460-454: Was a stack machine with instructions optimized for compiled Lisp. The early Lisp machines used microcode to provide the instruction set. For several operations, type checking and dispatching was done in hardware at runtime. For example, only one addition operation could be used with various numeric types (integer, float, rational, and complex numbers). The result was a very compact compiled representation of Lisp code. The following example uses
6545-454: Was affectionately referred to as the Knight machine , perhaps since Knight wrote his master's thesis on the subject; it was extremely well received. It was subsequently improved into a version called CADR (a pun; in Lisp, the cadr function, which returns the second item of a list, is pronounced /ˈkeɪ.dəɹ/ or /ˈkɑ.dəɹ/ , as some pronounce the word "cadre") which was based on essentially
6630-450: Was carried forth. Others (including Bill Gosper and Tom Knight ) felt that to be under the rule of Greenblatt was unacceptable. When Noftsker started Symbolics , while he was able to pay salaries, he didn't actually have a building or any equipment for the programmers 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
6715-686: 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 Lisp Machine Lisp , descended from MIT's Maclisp . The operating systems were written from the ground up in Lisp, often using object-oriented extensions. Later, these Lisp machines also supported various versions of Common Lisp (with Flavors , New Flavors , and Common Lisp Object System (CLOS)). Bolt, Beranek and Newman (BBN) developed its own Lisp machine, named Jericho, which ran
6800-453: Was lengthened to 36 bits for Symbolics 3600-model Lisp machines and eventually to 40 bits or more (usually, the excess bits not accounted for by the following were used for error-correcting codes ). 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
6885-500: Was mostly upward compatible with the CADR (source CADR microcode fragments could be reassembled), but there were improvements in instruction fetch and other hardware differences including use of a multiplier chip and a faster logic family and cache memory . The LAMBDA's processor cards were designed to work in a NuBus -based engineering workstation, the NuMachine , which had been originated by Steve Ward 's group at MIT, and, through
6970-897: Was ported to Common Lisp or later written in Common Lisp. Some later Lisp machines (like the TI MicroExplorer, the Symbolics MacIvory or the Symbolics UX400/1200) were no longer complete workstations, but boards designed to be embedded in host computers: Apple Macintosh II and Sun-3 or Sun-4 . Some Lisp machines, such as the Symbolics XL1200, had extensive graphics abilities using special graphics boards. These machines were used in domains like medical image processing, 3D animation, and CAD. Proprietary software Proprietary software
7055-399: Was reincarnated as GigaMos Systems ; Greenblatt was one of its officers. GigaMos, through the ownership of a Canadian backer named Guy Montpetit , bought the assets of LMI through a Chapter 11 bankruptcy reorganization. Prior to the incorporation of GigaMos, LMI developed a new Lisp machine called the "K-machine" which used a RISC -like architecture. Montpetit subsequently became embroiled in
7140-444: Was then considered a huge amount of computer power, as measured in processor time and memory space. The power requirements of AI research were exacerbated by the Lisp symbolic programming language, when commercial hardware was designed and optimized for assembly - and Fortran -like programming languages. At first, the cost of such computer hardware meant that it had to be shared among many users. As integrated circuit technology shrank
7225-507: Was trying to put together an AI natural language computer application, came to Greenblatt, seeking a Lisp machine for his group to work with. Eight months after Greenblatt had his disastrous conference with Noftsker, he had yet to produce anything. Alexander Jacobson decided that the only way Greenblatt was going to actually start his company and build the Lisp machines that Jacobson needed, was if he pushed and financially helped Greenblatt launch his company. Jacobson pulled together business plans,
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