153-563: Symbolics, Inc. , was a privately held American computer manufacturer that acquired the assets of the former company and continues to sell and maintain the Open Genera Lisp system and the Macsyma computer algebra system . The symbolics.com domain was originally registered on March 15, 1985, making it the first .com -domain in the world. In August 2009, it was sold to napkin.com (formerly XF.com) Investments. Symbolics, Inc.
306-706: A Balkanisation of the "Open Source Universe". Linus Torvalds, who decided not to adopt the GPLv3 for the Linux kernel, reiterated his criticism several years later. GPLv3 improved compatibility with several free software licenses such as the Apache License, version 2.0, and the GNU Affero General Public License, which GPLv2 could not be combined with. However, GPLv3 software could only be combined and share code with GPLv2 software if
459-521: A binary system meant that Zuse's machines were easier to build and potentially more reliable, given the technologies available at that time. The Z3 was not itself a universal computer but could be extended to be Turing complete . Zuse's next computer, the Z4 , became the world's first commercial computer; after initial delay due to the Second World War, it was completed in 1950 and delivered to
612-632: A central processing unit (CPU) in the form of a microprocessor , together with some type of computer memory , typically semiconductor memory chips. The processing element carries out arithmetic and logical operations, and a sequencing and control unit can change the order of operations in response to stored information . Peripheral devices include input devices ( keyboards , mice , joysticks , etc.), output devices ( monitors , printers , etc.), and input/output devices that perform both functions (e.g. touchscreens ). Peripheral devices allow information to be retrieved from an external source, and they enable
765-419: A keyboard , and computed and printed the results, demonstrating the feasibility of an electromechanical analytical engine. During the first half of the 20th century, many scientific computing needs were met by increasingly sophisticated analog computers, which used a direct mechanical or electrical model of the problem as a basis for computation . However, these were not programmable and generally lacked
918-524: A mass-production basis, which limited them to a number of specialized applications. At the University of Manchester , a team under the leadership of Tom Kilburn designed and built a machine using the newly developed transistors instead of valves. Their first transistorized computer and the first in the world, was operational by 1953 , and a second version was completed there in April 1955. However,
1071-429: A monolithic integrated circuit (IC) chip. Kilby's IC had external wire connections, which made it difficult to mass-produce. Noyce also came up with his own idea of an integrated circuit half a year later than Kilby. Noyce's invention was the first true monolithic IC chip. His chip solved many practical problems that Kilby's had not. Produced at Fairchild Semiconductor, it was made of silicon , whereas Kilby's chip
1224-622: A patent infringement claim or other litigation to impair users' freedom under the license. By 1990, it was becoming apparent that a less restrictive license would be strategically useful for the C library and for software libraries that essentially did the job of existing proprietary ones; when version 2 of the GPL (GPLv2) was released in June 1991, therefore, a second license – the GNU Library General Public License –
1377-452: A "user" and a "consumer product". It also explicitly removed the section on "Geographical Limitations", the probable removal of this section having been announced at the launch of the public consultation. The fourth discussion draft, which was the last, was released on 31 May 2007. It introduced Apache License version 2.0 compatibility (prior versions are incompatible), clarified the role of outside contractors, and made an exception to avoid
1530-652: A 1998 retrospective, it was the first working machine to contain all of the elements essential to a modern electronic computer. As soon as the Baby had demonstrated the feasibility of its design, a project began at the university to develop it into a practically useful computer, the Manchester Mark 1 . The Mark 1 in turn quickly became the prototype for the Ferranti Mark 1 , the world's first commercially available general-purpose computer. Built by Ferranti , it
1683-404: A 36- bit word (divided up as 4 or 8 bits of tags, and 32 bits of data or 28 bits of memory address). Memory words were 44 bits, the additional 8 bits being used for error-correcting code (ECC). The instruction set was that of a stack machine . The 3600 architecture provided 4,096 hardware registers, of which half were used as a cache for the top of the control stack ; the rest were used by
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#17327835611371836-541: A 3600 depending on the model and the revision of the Ivory chip. The Ivory instruction set was later emulated in software for microprocessors implementing the 64-bit Alpha architecture. The "Virtual Lisp Machine" emulator , combined with the operating system and software development environment from the XL machines, is sold as Open Genera. Sunstone was a processor similar to a reduced instruction set computer (RISC), that
1989-512: A Chip (SoCs) are complete computers on a microchip (or chip) the size of a coin. They may or may not have integrated RAM and flash memory . If not integrated, the RAM is usually placed directly above (known as Package on package ) or below (on the opposite side of the circuit board ) the SoC, and the flash memory is usually placed right next to the SoC. This is done to improve data transfer speeds, as
2142-408: A US federal court ruled that an open-source license is an enforceable contract. In October 2021 SFC sued Vizio over breach of contract as an end user to request source code for Vizio's TVs, a federal judge has ruled in the interim that the GPL is an enforceable contract by end users as well as a license for copyright holders. The text of the GPL is itself copyrighted , and the copyright is held by
2295-531: A cameo appearance in the movie Real Genius . The company was also referenced in Michael Crichton's novel Jurassic Park . Symbolics' Graphics Division was sold to Nichimen Trading Company in the early 1990s, and the S-Graphics software suite (S-Paint, S-Geometry, S-Dynamics, S-Render) ported to Franz Allegro Common Lisp on Silicon Graphics (SGI) and PC computers running Windows NT . Today it
2448-491: A custom Symbolics Hardware Design Language (HDL), addressed a 40-bit word (8 bits tag, 32 bits data/address). Since it only addressed full words and not bytes or half-words, this allowed addressing of 4 Gigawords (GW) or 16 gigabytes (GB) of memory; the increase in address space reflected the growth of programs and data as semiconductor memory and disk space became cheaper. The Ivory processor had 8 bits of ECC attached to each word, so each word fetched from external memory to
2601-489: A hacker's software could remain free software . In this way, Symbolics played a key, albeit adversarial, role in instigating the free software movement . In 1983, a year later than planned, Symbolics introduced the 3600 family of Lisp machines. Code-named the "L-machine" internally, the 3600 family was an innovative new design, inspired by the CADR architecture but sharing few of its implementation details. The main processor had
2754-443: A licensee has no right to redistribute it, not even in modified form (barring fair use ), except under the terms of the license. One is only required to adhere to the terms of the GPL if one wishes to exercise rights normally restricted by copyright law, such as redistribution. Conversely, if one distributes copies of the work without abiding by the terms of the GPL (for instance, by keeping the source code secret), they can be sued by
2907-403: A medieval European counting house , a checkered cloth would be placed on a table, and markers moved around on it according to certain rules, as an aid to calculating sums of money. The Antikythera mechanism is believed to be the earliest known mechanical analog computer , according to Derek J. de Solla Price . It was designed to calculate astronomical positions. It was discovered in 1901 in
3060-460: A modified derivative of a GPL licensed content management system is not required to distribute its changes to the underlying software, because the modified web portal is not being redistributed but rather hosted, and also because the web portal output is also not a derivative work of the GPL licensed content management system. There has been debate on whether it is a violation of the GPLv1 to release
3213-525: A much more general design, an analytical engine , was possible. The input of programs and data was to be provided to the machine via punched cards , a method being used at the time to direct mechanical looms such as the Jacquard loom . For output, the machine would have a printer, a curve plotter and a bell. The machine would also be able to punch numbers onto cards to be read in later. The engine would incorporate an arithmetic logic unit , control flow in
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#17327835611373366-529: A number of successes at breaking encrypted German military communications. The German encryption machine, Enigma , was first attacked with the help of the electro-mechanical bombes which were often run by women. To crack the more sophisticated German Lorenz SZ 40/42 machine, used for high-level Army communications, Max Newman and his colleagues commissioned Flowers to build the Colossus . He spent eleven months from early February 1943 designing and building
3519-646: A parallel variant of Lisp and, initially, was used primarily by the AI community, so the Symbolics Lisp machine was a particularly good fit as a front-end machine. For a long time, the operating system didn't have a name, but was finally named Genera around 1984. The system included several advanced dialects of Lisp. Its heritage was Maclisp on the PDP-10, but it included more data types, and multiple-inheritance object-oriented programming features. This Lisp dialect
3672-562: A sequence of sets of values. The whole machine was to be controlled by a read-only program, which was complete with provisions for conditional branching . He also introduced the idea of floating-point arithmetic . In 1920, to celebrate the 100th anniversary of the invention of the arithmometer , Torres presented in Paris the Electromechanical Arithmometer, which allowed a user to input arithmetic problems through
3825-536: A series of widely used free software licenses , or copyleft licenses, that guarantee end users the freedoms to run, study, share, and modify the software. The GPL was the first copyleft license for general use. It was originally written by Richard Stallman , the founder of the Free Software Foundation (FSF), for the GNU Project . The license grants the recipients of a computer program
3978-681: A simplified version (at right), known simply as the Symbolics keyboard . The Symbolics keyboard featured the many modifier keys used in Zmacs, notably Control/Meta/Super/Hyper in a block, but did not feature the complex symbol set of the space-cadet keyboard. Also contributing to the 3600 series' success was a line of bit-mapped graphics color video interfaces, combined with extremely powerful animation software. Symbolics' Graphics Division, headquartered in Westwood, Los Angeles , California, near to
4131-460: A successful demonstration of its use in computing tables in 1906. In his work Essays on Automatics published in 1914, Leonardo Torres Quevedo wrote a brief history of Babbage's efforts at constructing a mechanical Difference Engine and Analytical Engine. The paper contains a design of a machine capable to calculate formulas like a x ( y − z ) 2 {\displaystyle a^{x}(y-z)^{2}} , for
4284-402: A universal Turing machine. Early computing machines had fixed programs. Changing its function required the re-wiring and re-structuring of the machine. With the proposal of the stored-program computer this changed. A stored-program computer includes by design an instruction set and can store in memory a set of instructions (a program ) that details the computation . The theoretical basis for
4437-559: A user command) would only specify the name of the host and the desired service. For example, a host name and a request for "Terminal Connection" might yield a connection over TCP/IP using the Telnet protocol (although there were many other possibilities). Likewise, requesting a file operation (such as a Copy File command) might pick NFS , FTP , NFILE (the Symbolics network file access protocol), or one of several others, and it might execute
4590-577: A wide range of tasks. The term computer system may refer to a nominally complete computer that includes the hardware , operating system , software , and peripheral equipment needed and used for full operation; or to a group of computers that are linked and function together, such as a computer network or computer cluster . A broad range of industrial and consumer products use computers as control systems , including simple special-purpose devices like microwave ovens and remote controls , and factory devices like industrial robots . Computers are at
4743-418: Is allowed to charge a fee for this service or do this free of charge. This latter point distinguishes the GPL from software licenses that prohibit commercial redistribution. The FSF argues that free software should not place restrictions on commercial use, and the GPL explicitly states that GPL works may be sold at any price. The GPL additionally states that a distributor may not impose "further restrictions on
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4896-449: Is applied to ensure that end users retain the freedoms defined above. However, software running as an application program under a GPL-licensed operating system such as Linux is not required to be licensed under GPL or to be distributed with source-code availability—the licensing depends only on the used libraries and software components and not on the underlying platform. For example, if a program consists only of original source code , or
5049-427: Is combined with source code from other software components , then the custom software components need not be licensed under GPL and need not make their source code available; even if the underlying operating system used is licensed under the GPL, applications running on it are not considered derivative works. Only if GPL licensed parts are used in a program (and the program is distributed), then all other source code of
5202-501: Is how the compiled code was available and there are "clear directions" on where to find the source code. The FSF does not hold the copyright for a work released under the GPL unless an author explicitly assigns copyrights to the FSF (which seldom happens except for programs that are part of the GNU project). Only the individual copyright holders have the authority to sue when a license violation
5355-500: Is prohibited by copyright law . The FSF argues that freedom-respecting free software should also not restrict commercial use and distribution (including redistribution): In purely private (or internal) use—with no sales and no distribution—the software code may be modified and parts reused without requiring the source code to be released. For sales or distribution, the entire source code needs to be made available to end users, including any code changes and additions—in that case, copyleft
5508-713: Is sold as Mirai by Izware LLC, and continues to be used in major motion pictures (most famously in New Line Cinema's The Lord of the Rings ), video games, and military simulations. Symbolics' 3600-series computers were also used as the first front end controller computers for the Connection Machine massively parallel computers manufactured by Thinking Machines Corporation , another MIT spinoff based in Cambridge, Massachusetts. The Connection Machine ran
5661-557: Is still registered, the oldest) registered .com domain of the Internet . The symbolics.com domain was purchased by Napkin.com in 2009. Genera also featured the most extensive networking interoperability software seen to that point. A local area network system called Chaosnet had been invented for the Lisp Machine (predating the commercial availability of Ethernet ). The Symbolics system supported Chaosnet, but also had one of
5814-499: Is suspected. Software under the GPL may be run for all purposes, including commercial purposes and even as a tool for creating proprietary software , such as when using GPL-licensed compilers . Users or companies who distribute GPL-licensed works (e.g. software), may charge a fee for copies or give them free of charge. This distinguishes the GPL from shareware software licenses that allow copying for personal use but prohibit commercial distribution or proprietary licenses where copying
5967-463: Is the stored program , where all the instructions for computing are stored in memory. Von Neumann acknowledged that the central concept of the modern computer was due to this paper. Turing machines are to this day a central object of study in theory of computation . Except for the limitations imposed by their finite memory stores, modern computers are said to be Turing-complete , which is to say, they have algorithm execution capability equivalent to
6120-698: The ASP loophole in the GPL . As there were concerns expressed about the administrative costs of checking code for this additional requirement, it was decided to keep the GPL and the AGPL license separated. Others, notably some high-profile Linux kernel developers such as Linus Torvalds , Greg Kroah-Hartman , and Andrew Morton , commented to the mass media and made public statements about their objections to parts of discussion drafts 1 and 2. The kernel developers referred to GPLv3 draft clauses regarding DRM / Tivoization , patents, and "additional restrictions", and warned of
6273-508: The AGPL (v1) , and patent deals between Microsoft and distributors of free and open-source software, which some viewed as an attempt to use patents as a weapon against the free software community. Version 3 was developed as an attempt to address these concerns and was officially released on 29 June 2007. Version 1 of the GNU GPL, released on 25 February 1989, was written to protect against
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6426-619: The Antikythera wreck off the Greek island of Antikythera , between Kythera and Crete , and has been dated to approximately c. 100 BCE . Devices of comparable complexity to the Antikythera mechanism would not reappear until the fourteenth century. Many mechanical aids to calculation and measurement were constructed for astronomical and navigation use. The planisphere was a star chart invented by Abū Rayhān al-Bīrūnī in
6579-556: The Defense Advanced Research Projects Agency ( DARPA ) had invested heavily in AI solutions, severely damaged Symbolics. An internal war between Noftsker and the CEO the board had hired in 1986, Brian Sear, over whether to follow Sun's suggested lead and focus on selling their software, or to re-emphasize their superior hardware, and the ensuing lack of focus when both Noftsker and Sear were fired from
6732-507: The E6B circular slide rule used for time and distance calculations on light aircraft. In the 1770s, Pierre Jaquet-Droz , a Swiss watchmaker , built a mechanical doll ( automaton ) that could write holding a quill pen. By switching the number and order of its internal wheels different letters, and hence different messages, could be produced. In effect, it could be mechanically "programmed" to read instructions. Along with two other complex machines,
6885-641: The ETH Zurich . The computer was manufactured by Zuse's own company, Zuse KG , which was founded in 1941 as the first company with the sole purpose of developing computers in Berlin. The Z4 served as the inspiration for the construction of the ERMETH , the first Swiss computer and one of the first in Europe. Purely electronic circuit elements soon replaced their mechanical and electromechanical equivalents, at
7038-492: The Software Freedom Law Center . According to Stallman, the most important changes were in relation to software patents , free software license compatibility, the definition of "source code", and hardware restrictions on software modifications, such as tivoization . Other changes related to internationalization, how license violations are handled, and how additional permissions could be granted by
7191-555: The WIPO Copyright Treaty , and that those who convey the work waive all legal power to prohibit circumvention of the technical protection measure "to the extent such circumvention is effected by exercising rights under this License with respect to the covered work". This means that users cannot be held liable for circumventing DRM implemented using GPLv3-licensed code under laws such as the U.S. Digital Millennium Copyright Act (DMCA). The distribution rights granted by
7344-476: The microcode and time-critical routines of the operating system and Lisp run-time environment. Hardware support was provided for virtual memory , which was common for machines in its class, and for garbage collection , which was unique. The original 3600 processor was a microprogrammed design like the CADR, and was built on several large circuit boards from standard TTL integrated circuits , both features being common for commercial computers in its class at
7497-497: The microcomputer revolution in the 1970s. The speed, power, and versatility of computers have been increasing dramatically ever since then, with transistor counts increasing at a rapid pace ( Moore's law noted that counts doubled every two years), leading to the Digital Revolution during the late 20th and early 21st centuries. Conventionally, a modern computer consists of at least one processing element , typically
7650-504: The "second generation" of computers. Compared to vacuum tubes, transistors have many advantages: they are smaller, and require less power than vacuum tubes, so give off less heat. Junction transistors were much more reliable than vacuum tubes and had longer, indefinite, service life. Transistorized computers could contain tens of thousands of binary logic circuits in a relatively compact space. However, early junction transistors were relatively bulky devices that were difficult to manufacture on
7803-525: The 1920s, Vannevar Bush and others developed mechanical differential analyzers. In the 1890s, the Spanish engineer Leonardo Torres Quevedo began to develop a series of advanced analog machines that could solve real and complex roots of polynomials , which were published in 1901 by the Paris Academy of Sciences . Charles Babbage , an English mechanical engineer and polymath , originated
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#17327835611377956-427: The 3600 family were popular for artificial intelligence (AI) research and commercial applications throughout the 1980s. The AI commercialization boom of the 1980s led directly to Symbolics' success during the decade. Symbolics computers were widely believed to be the best platform available for developing AI software. The LM-2 used a Symbolics-branded version of the complex space-cadet keyboard , while later models used
8109-619: The Cambridge EDSAC of 1949, became operational in April 1951 and ran the world's first routine office computer job . The concept of a field-effect transistor was proposed by Julius Edgar Lilienfeld in 1925. John Bardeen and Walter Brattain , while working under William Shockley at Bell Labs , built the first working transistor , the point-contact transistor , in 1947, which was followed by Shockley's bipolar junction transistor in 1948. From 1955 onwards, transistors replaced vacuum tubes in computer designs, giving rise to
8262-591: The EDVAC in 1945. The Manchester Baby was the world's first stored-program computer . It was built at the University of Manchester in England by Frederic C. Williams , Tom Kilburn and Geoff Tootill , and ran its first program on 21 June 1948. It was designed as a testbed for the Williams tube , the first random-access digital storage device. Although the computer was described as "small and primitive" by
8415-455: The ENIAC were six women, often known collectively as the "ENIAC girls". It combined the high speed of electronics with the ability to be programmed for many complex problems. It could add or subtract 5000 times a second, a thousand times faster than any other machine. It also had modules to multiply, divide, and square root. High speed memory was limited to 20 words (about 80 bytes). Built under
8568-657: The Free Software Foundation. The FSF permits people to create new licenses based on the GPL, as long as the derived licenses do not use the GPL preamble without permission. This is discouraged, however, since such a license might be incompatible with the GPL and causes a perceived license proliferation . Other licenses created by the GNU project include the GNU Lesser General Public License , GNU Free Documentation License , and GNU Affero General Public License . The text of
8721-404: The GPL for modified versions of the work are not unconditional. When someone distributes a GPL licensed work plus their own modifications, the requirements for distributing the whole work cannot be any greater than the requirements that are in the GPL. This requirement is known as copyleft. It earns its legal power from the use of copyright on software programs. Because a GPL work is copyrighted,
8874-527: The GPL is not itself under the GPL. The license's copyright disallows modification of the license. Copying and distributing the license is allowed since the GPL requires recipients to get "a copy of this License along with the Program". According to the GPL FAQ, anyone can make a new license using a modified version of the GPL as long as they use a different name for the license, do not mention "GNU", and remove
9027-539: The GPL license family has been one of the most popular software licenses in the free and open-source software (FOSS) domain. Prominent free software programs licensed under the GPL include the Linux kernel and the GNU Compiler Collection (GCC). David A. Wheeler argues that the copyleft provided by the GPL was crucial to the success of Linux -based systems, giving the programmers who contributed to
9180-588: The GPL license includes an optional "any later version" clause, allowing users to choose between the original terms or the terms in new versions as updated by the FSF. Software projects licensed with the optional "or later" clause include the GNU Project, while projects like the Linux kernel is licensed under GPLv2 only. The "or any later version" clause is sometimes known as a "lifeboat clause" since it allows combinations between different versions of GPL-licensed software to maintain compatibility. The original GPL
9333-431: The GPL licensed program, they may still use the software within their organization however they like, and works (including programs) constructed by the use of the program are not required to be covered by this license. Software developer Allison Randal argued that the GPLv3 as a license is unnecessarily confusing for lay readers, and could be simplified while retaining the same conditions and legal force. In April 2017,
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#17327835611379486-464: The GPLv2 license used had the optional "or later" clause and the software was upgraded to GPLv3. While the "GPLv2 or any later version" clause is considered by FSF as the most common form of licensing GPLv2 software, Toybox developer Rob Landley described it as a lifeboat clause . Software projects licensed with the optional "or later" clause include the GNU Project , while a prominent example without
9639-881: The Ivory chip. The initial Ivory processors were fabricated by VLSI Technology Inc in San Jose, California , on a 2 μm CMOS process, with later generations fabricated by Hewlett-Packard in Corvallis, Oregon , on 1.25 μm and 1 μm CMOS processes. The Ivory had a stack architecture and operated a 4-stage pipeline: Fetch, Decode, Execute and Write Back. Ivory processors were marketed in stand-alone Lisp Machines (the XL400, XL1200, and XL1201), headless Lisp Machines (NXP1000), and on add-in cards for Sun Microsystems (UX400, UX1200) and Apple Macintosh (MacIvory I, II, III) computers. The Lisp Machines with Ivory processors operated at speeds that were between two and six times faster than
9792-531: The MOS transistor, was invented at Bell Labs between 1955 and 1960 and was the first truly compact transistor that could be miniaturized and mass-produced for a wide range of uses. With its high scalability , and much lower power consumption and higher density than bipolar junction transistors, the MOSFET made it possible to build high-density integrated circuits . In addition to data processing, it also enabled
9945-488: The OS and environment. Symbolics felt that they no longer had sufficient control over their product. At that point, Symbolics began using their own copy of the software, located on their company servers, while Stallman says that Symbolics did that to prevent its Lisp improvements from flowing to Lisp Machines, Inc. From that base, Symbolics made extensive improvements to every part of the software, and continued to deliver almost all
10098-455: The Scottish scientist Sir William Thomson in 1872 was of great utility to navigation in shallow waters. It used a system of pulleys and wires to automatically calculate predicted tide levels for a set period at a particular location. The differential analyser , a mechanical analog computer designed to solve differential equations by integration , used wheel-and-disc mechanisms to perform
10251-540: The Software Package Data Exchange (SPDX). The license includes instructions to specify "version 2 of the License, or (at your option) any later version" to allow the flexible optional use of either version 2 or 3, but some developers change this to specify "version 2" only. In late 2005, the Free Software Foundation (FSF) announced work on version 3 of the GPL (GPLv3). On 16 January 2006,
10404-493: The U.S. Although the ENIAC was similar to the Colossus, it was much faster, more flexible, and it was Turing-complete. Like the Colossus, a "program" on the ENIAC was defined by the states of its patch cables and switches, a far cry from the stored program electronic machines that came later. Once a program was written, it had to be mechanically set into the machine with manual resetting of plugs and switches. The programmers of
10557-586: The US, John Vincent Atanasoff and Clifford E. Berry of Iowa State University developed and tested the Atanasoff–Berry Computer (ABC) in 1942, the first "automatic electronic digital computer". This design was also all-electronic and used about 300 vacuum tubes, with capacitors fixed in a mechanically rotating drum for memory. During World War II, the British code-breakers at Bletchley Park achieved
10710-898: The advent of the integrated circuit (IC). The idea of the integrated circuit was first conceived by a radar scientist working for the Royal Radar Establishment of the Ministry of Defence , Geoffrey W.A. Dummer . Dummer presented the first public description of an integrated circuit at the Symposium on Progress in Quality Electronic Components in Washington, D.C. , on 7 May 1952. The first working ICs were invented by Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor . Kilby recorded his initial ideas concerning
10863-647: The basic concept which underlies all electronic digital computers. By 1938, the United States Navy had developed an electromechanical analog computer small enough to use aboard a submarine . This was the Torpedo Data Computer , which used trigonometry to solve the problem of firing a torpedo at a moving target. During World War II similar devices were developed in other countries as well. Early digital computers were electromechanical ; electric switches drove mechanical relays to perform
11016-530: The best Arithmetician that euer [ sic ] breathed, and he reduceth thy dayes into a short number." This usage of the term referred to a human computer , a person who carried out calculations or computations . The word continued to have the same meaning until the middle of the 20th century. During the latter part of this period, women were often hired as computers because they could be paid less than their male counterparts. By 1943, most human computers were women. The Online Etymology Dictionary gives
11169-570: The calculation. These devices had a low operating speed and were eventually superseded by much faster all-electric computers, originally using vacuum tubes . The Z2 , created by German engineer Konrad Zuse in 1939 in Berlin , was one of the earliest examples of an electromechanical relay computer. In 1941, Zuse followed his earlier machine up with the Z3 , the world's first working electromechanical programmable , fully automatic digital computer. The Z3
11322-420: The chip was actually 48 bits wide. Each Ivory instruction was 18 bits wide and two instructions plus a 2-bit CDR code and 2-bit Data Type were in each instruction word fetched from memory. Fetching two instruction words at a time from memory enhanced the Ivory's performance. Unlike the 3600's microprogrammed architecture, the Ivory instruction set was still microcoded, but was stored in a 1200 × 180-bit ROM inside
11475-429: The clause is the Linux kernel. The final version of the license text was published on 29 June 2007. The terms and conditions of the GPL must be made available to anybody receiving a copy of a work that has a GPL applied to it ("the licensee"). Any licensee who adheres to the terms and conditions is given permission to modify the work, as well as to copy and redistribute the work or any derivative version. The licensee
11628-706: The commercial advantages of purpose-built Lisp machines. By 1995, the Lisp machine era had ended, and with it Symbolics' hopes for success. Symbolics continued as an enterprise with very limited revenues, supported mainly by service contracts on the remaining MacIvory, UX-1200, UX-1201, and other machines still used by commercial customers. Symbolics also sold Virtual Lisp Machine (VLM) software for DEC, Compaq, and HP Alpha-based workstations ( AlphaStation ) and servers ( AlphaServer ), refurbished MacIvory IIs, and Symbolics keyboards. In July 2005, Symbolics closed its Chatsworth, California , maintenance facility. The reclusive owner of
11781-554: The company caused sales to plummet. This, combined with some ill-advised real estate deals by company management during the boom years (they had entered into large long-term lease obligations in California), drove Symbolics into bankruptcy . Rapid evolution in mass market microprocessor technology (the PC revolution ), advances in Lisp compiler technology, and the economics of manufacturing custom microprocessors severely diminished
11934-558: The company, Andrew Topping, died that same year. The current legal status of Symbolics software is uncertain. An assortment of Symbolics hardware was still available for purchase as of August 2007. In 2011, the United States Department of Defense (US DoD) awarded Symbolics a 5 year contract for maintenance work, ending in September 2016. On March 15, 1985, symbolics.com became the first (and currently, since it
12087-458: The company, was housed in a cabinet derived from the 3640s. Denser memory and smaller disk drives enabled the introduction of the 3620, about the size of a modern full-size tower PC. The 3630 was a fat 3620 with room for more memory and video interface cards. The 3610 was a lower priced variant of the 3620, essentially identical in every way except that it was licensed for application deployment rather than general development. The various models of
12240-565: The concept of a programmable computer. Considered the " father of the computer ", he conceptualized and invented the first mechanical computer in the early 19th century. After working on his difference engine he announced his invention in 1822, in a paper to the Royal Astronomical Society , titled "Note on the application of machinery to the computation of astronomical and mathematical tables". He also designed to aid in navigational calculations, in 1833 he realized that
12393-470: The copyright holder. The concept of "software propagation", as a term for the copying and duplication of software, was explicitly defined. The public consultation process was coordinated by the Free Software Foundation with assistance from Software Freedom Law Center, Free Software Foundation Europe , and other free software groups. Comments were collected from the public via the gplv3.fsf.org web portal, using purpose-written software called stet . During
12546-704: The core of general-purpose devices such as personal computers and mobile devices such as smartphones . Computers power the Internet , which links billions of computers and users. Early computers were meant to be used only for calculations. Simple manual instruments like the abacus have aided people in doing calculations since ancient times. Early in the Industrial Revolution , some mechanical devices were built to automate long, tedious tasks, such as guiding patterns for looms . More sophisticated electrical machines did specialized analog calculations in
12699-499: The data signals do not have to travel long distances. Since ENIAC in 1945, computers have advanced enormously, with modern SoCs (such as the Snapdragon 865) being the size of a coin while also being hundreds of thousands of times more powerful than ENIAC, integrating billions of transistors, and consuming only a few watts of power. The first mobile computers were heavy and ran from mains power. The 50 lb (23 kg) IBM 5100
12852-515: The decision of the British Government to cease funding. Babbage's failure to complete the analytical engine can be chiefly attributed to political and financial difficulties as well as his desire to develop an increasingly sophisticated computer and to move ahead faster than anyone else could follow. Nevertheless, his son, Henry Babbage , completed a simplified version of the analytical engine's computing unit (the mill ) in 1888. He gave
13005-460: The direction of John Mauchly and J. Presper Eckert at the University of Pennsylvania, ENIAC's development and construction lasted from 1943 to full operation at the end of 1945. The machine was huge, weighing 30 tons, using 200 kilowatts of electric power and contained over 18,000 vacuum tubes, 1,500 relays, and hundreds of thousands of resistors, capacitors, and inductors. The principle of
13158-483: The doll is at the Musée d'Art et d'Histoire of Neuchâtel , Switzerland , and still operates. In 1831–1835, mathematician and engineer Giovanni Plana devised a Perpetual Calendar machine , which through a system of pulleys and cylinders could predict the perpetual calendar for every year from 0 CE (that is, 1 BCE) to 4000 CE, keeping track of leap years and varying day length. The tide-predicting machine invented by
13311-481: The early 11th century. The astrolabe was invented in the Hellenistic world in either the 1st or 2nd centuries BCE and is often attributed to Hipparchus . A combination of the planisphere and dioptra , the astrolabe was effectively an analog computer capable of working out several different kinds of problems in spherical astronomy . An astrolabe incorporating a mechanical calendar computer and gear -wheels
13464-513: The early 1980s. At the 3600's introduction, the smallest disk that could support the ZetaLisp software was 14 inches (360 mm) wide (most 3600s shipped with the 10½-inch Fujitsu Eagle ). The 3670 and 3675 were slightly shorter in height, but were essentially the same machine packed a little tighter. The advent of 8 inches (200 mm), and later 5 + 1 ⁄ 4 inches (130 mm), disk drives that could hold hundreds of megabytes led to
13617-445: The early 2000s. These smartphones and tablets run on a variety of operating systems and recently became the dominant computing device on the market. These are powered by System on a Chip (SoCs), which are complete computers on a microchip the size of a coin. Computers can be classified in a number of different ways, including: GNU General Public License The GNU General Public Licenses ( GNU GPL or simply GPL ) are
13770-399: The early 20th century. The first digital electronic calculating machines were developed during World War II , both electromechanical and using thermionic valves . The first semiconductor transistors in the late 1940s were followed by the silicon -based MOSFET (MOS transistor) and monolithic integrated circuit chip technologies in the late 1950s, leading to the microprocessor and
13923-477: The exact definition of the term "microprocessor", it is largely undisputed that the first single-chip microprocessor was the Intel 4004 , designed and realized by Federico Faggin with his silicon-gate MOS IC technology, along with Ted Hoff , Masatoshi Shima and Stanley Mazor at Intel . In the early 1970s, MOS IC technology enabled the integration of more than 10,000 transistors on a single chip. System on
14076-507: The first TCP/IP implementations. It also supported DECnet and IBM's SNA network protocols. A Dialnet protocol used phone lines and modems . Genera would, using hints from its distributed namespace database (somewhat similar to Domain Name System (DNS), but more comprehensive, like parts of Xerox's Grapevine), automatically select the best protocol combination to use when connecting to network service. An application program (or
14229-399: The first "discussion draft" of GPLv3 was published, and the public consultation began. The public consultation was originally planned for nine to fifteen months, but ultimately lasted eighteen months, with four drafts being published. The official GPLv3 was released by the FSF on 29 June 2007. GPLv3 was written by Richard Stallman, with legal counsel from Eben Moglen and Richard Fontana from
14382-508: The first Colossus. After a functional test in December 1943, Colossus was shipped to Bletchley Park, where it was delivered on 18 January 1944 and attacked its first message on 5 February. Colossus was the world's first electronic digital programmable computer. It used a large number of valves (vacuum tubes). It had paper-tape input and was capable of being configured to perform a variety of boolean logical operations on its data, but it
14535-725: The first attested use of computer in the 1640s, meaning 'one who calculates'; this is an "agent noun from compute (v.)". The Online Etymology Dictionary states that the use of the term to mean " 'calculating machine' (of any type) is from 1897." The Online Etymology Dictionary indicates that the "modern use" of the term, to mean 'programmable digital electronic computer' dates from "1945 under this name; [in a] theoretical [sense] from 1937, as Turing machine ". The name has remained, although modern computers are capable of many higher-level functions. Devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with fingers . The earliest counting device
14688-542: The first implementation of the Hewlett-Packard Precision Architecture ( PA-RISC ). Symbolics' research and development staff (first at MIT, and then later at the company) produced several major innovations in software technology: The Symbolics Graphics Division (SGD, founded in 1982, sold to Nichimen Graphics in 1992) developed the S-Graphics software suite (S-Paint, S-Geometry, S-Dynamics, S-Render) for Symbolics Genera. This software
14841-409: The form of conditional branching and loops , and integrated memory , making it the first design for a general-purpose computer that could be described in modern terms as Turing-complete . The machine was about a century ahead of its time. All the parts for his machine had to be made by hand – this was a major problem for a device with thousands of parts. Eventually, the project was dissolved with
14994-466: The integrated circuit in July 1958, successfully demonstrating the first working integrated example on 12 September 1958. In his patent application of 6 February 1959, Kilby described his new device as "a body of semiconductor material ... wherein all the components of the electronic circuit are completely integrated". However, Kilby's invention was a hybrid integrated circuit (hybrid IC), rather than
15147-411: The integration. In 1876, Sir William Thomson had already discussed the possible construction of such calculators, but he had been stymied by the limited output torque of the ball-and-disk integrators . In a differential analyzer, the output of one integrator drove the input of the next integrator, or a graphing output. The torque amplifier was the advance that allowed these machines to work. Starting in
15300-410: The introduction of the 3640 and 3645, which were roughly the size of a two-drawer file cabinet. Later versions of the 3600 architecture were implemented on custom integrated circuits, reducing the five cards of the original processor design to two, at a large manufacturing cost savings and with performance slightly better than the old design. The 3650, first of the G machines , as they were known within
15453-416: The kernel assurance that their work would benefit the whole world and remain free, rather than being exploited by software companies that would not have to give anything back to the community. In 2007, the third version of the license (GPLv3) was released to address some perceived problems with the second version (GPLv2) which were discovered during the latter's long-time usage. To keep the license current,
15606-536: The legal distinction between a license and a contract is an important one: contracts are enforceable by contract law , whereas licenses are enforced under copyright law . However, this distinction is not useful in the many jurisdictions where there are no differences between contracts and licenses, such as civil law systems. Those who do not accept the GPL's terms and conditions do not have permission, under copyright law, to copy or distribute GPL-licensed software or derivative works. However, if they do not redistribute
15759-420: The license. Copyleft applies only when a person seeks to redistribute the program. Developers may make private modified versions with no obligation to divulge the modifications, as long as they do not distribute the modified software to anyone else. Copyleft applies only to the software, and not to its output (unless that output is itself a derivative work of the program). For example, a public web portal running
15912-590: The machine did make use of valves to generate its 125 kHz clock waveforms and in the circuitry to read and write on its magnetic drum memory , so it was not the first completely transistorized computer. That distinction goes to the Harwell CADET of 1955, built by the electronics division of the Atomic Energy Research Establishment at Harwell . The metal–oxide–silicon field-effect transistor (MOSFET), also known as
16065-521: The major Hollywood movie and television studios, made its S-Render and S-Paint software into industry leaders in the animation business and its 24 fps lock displays were featured in Star Trek movies. Symbolics developed the first workstations able to process high-definition television (HDTV) quality video, which enjoyed a popular following in Japan. A 3600, with the standard black-and-white monitor, made
16218-431: The major change in GPLv2 was the "Liberty or Death" clause, as he calls it – Section 7. The section says that licensees may distribute a GPL-covered work only if they can satisfy all of the license's obligations, despite any other legal obligations they might have. In other words, the obligations of the license may not be severed due to conflicting obligations. This provision is intended to discourage any party from using
16371-452: The modern computer was proposed by Alan Turing in his seminal 1936 paper, On Computable Numbers . Turing proposed a simple device that he called "Universal Computing machine" and that is now known as a universal Turing machine . He proved that such a machine is capable of computing anything that is computable by executing instructions (program) stored on tape, allowing the machine to be programmable. The fundamental concept of Turing's design
16524-403: The more famous Sir William Thomson. The art of mechanical analog computing reached its zenith with the differential analyzer , built by H. L. Hazen and Vannevar Bush at MIT starting in 1927. This built on the mechanical integrators of James Thomson and the torque amplifiers invented by H. W. Nieman. A dozen of these devices were built before their obsolescence became obvious. By the 1950s,
16677-453: The original author under copyright law. Copyright law has historically been used to prevent distribution of work by parties not authorized by the creator. Copyleft uses the same copyright laws to accomplish a very different goal. It grants rights to distribution to all parties insofar as they provide the same rights to subsequent ones, and they to the next, etc. In this way, the GPL and other copyleft licenses attempt to enforce libre access to
16830-509: The parties who would receive the covered work from you, a discriminatory patent license ... This aimed to make such future deals ineffective. The license was also meant to cause Microsoft to extend the patent licenses it granted to Novell customers for the use of GPLv3 software to all users of that GPLv3 software; this was possible only if Microsoft was legally a "conveyor" of the GPLv3 software. Early drafts of GPLv3 also let licensors add an AGPL -like requirement that would have plugged
16983-457: The perceived problems of a Microsoft–Novell style agreement, saying in Section 11 paragraph 6 that: You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of
17136-486: The practical use of MOS transistors as memory cell storage elements, leading to the development of MOS semiconductor memory , which replaced earlier magnetic-core memory in computers. The MOSFET led to the microcomputer revolution , and became the driving force behind the computer revolution . The MOSFET is the most widely used transistor in computers, and is the fundamental building block of digital electronics . The next great advance in computing power came with
17289-409: The preamble, though the preamble can be used in a modified license if permission to use it is obtained from the Free Software Foundation (FSF). According to the FSF, "The GPL does not require you to release your modified version or any part of it. You are free to make modifications and use them privately, without ever releasing them." However, if one releases a GPL-licensed entity to the public, there
17442-533: The premier software development environments of the 1980s and 1990s, now sold commercially as Open Genera for Tru64 UNIX on the Hewlett-Packard (HP) Alpha . The Lisp Machine was the first commercially available workstation , although that word had not yet been coined. Symbolics was a spinoff from the MIT AI Lab , one of two companies to be founded by AI Lab staffers and associated hackers for
17595-526: The program needs to be made available under the same license terms. The GNU Lesser General Public License (LGPL) was created to have a weaker copyleft than the GPL, in that it does not require custom-developed source code (distinct from the LGPL licensed parts) to be made available under the same license terms. The fifth section of version 3 states that no GPL-licensed code shall be considered an effective "technical protection measure" as defined by Article 11 of
17748-420: The public consultation process, 962 comments were submitted for the first draft. By the end of the comment period, a total of 2,636 comments had been submitted. The third draft was released on 28 March 2007. This draft included language intended to prevent patent-related agreements such as the controversial Microsoft-Novell patent agreement , and restricted the anti-tivoization clauses to a legal definition of
17901-570: The purpose of manufacturing Lisp machines. The other was Lisp Machines , Inc., although Symbolics attracted most of the hackers, and more funding. Symbolics' initial product, the LM-2, introduced in 1981, was a repackaged version of the MIT CADR Lisp machine design. The operating system and software development environment, over 500,000 lines, was written in Lisp from the microcode up, based on MIT's Lisp Machine Lisp . The software bundle
18054-530: The request over TCP/IP, Chaosnet, or whatever other network was most suitable. The most popular application program for the Symbolics Lisp Machine was the ICAD computer-aided engineering system. One of the first networked multi-player video games, a version of Spacewar , was developed for the Symbolics Lisp Machine in 1983. Electronic CAD software on the Symbolics Lisp Machine was used to develop
18207-548: The results of operations to be saved and retrieved. It was not until the mid-20th century that the word acquired its modern definition; according to the Oxford English Dictionary , the first known use of the word computer was in a different sense, in a 1613 book called The Yong Mans Gleanings by the English writer Richard Brathwait : "I haue [ sic ] read the truest computer of Times, and
18360-426: The rights granted by the GPL". This forbids activities such as distributing the software under a non-disclosure agreement or contract. The fourth section for version 2 of the license and the seventh section of version 3 require that programs distributed as pre-compiled binaries be accompanied by a copy of the source code, a written offer to distribute the source code via the same mechanism as the pre-compiled binary, or
18513-566: The rights of the Free Software Definition . The licenses in the GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. It is more restrictive than the Lesser General Public License and even further distinct from the more widely-used permissive software licenses such as BSD , MIT , and Apache . Historically,
18666-591: The same time that digital calculation replaced analog. The engineer Tommy Flowers , working at the Post Office Research Station in London in the 1930s, began to explore the possible use of electronics for the telephone exchange . Experimental equipment that he built in 1934 went into operation five years later, converting a portion of the telephone exchange network into an electronic data processing system, using thousands of vacuum tubes . In
18819-459: The slower peripherals during normal operation. An Ethernet interface was standard equipment, replacing the Chaosnet interface of the LM-2. The 3600 was roughly the size of a household refrigerator. This was partly due to the size of the processor (the cards were widely spaced to allow wire-wrap prototype cards to fit without interference) and partly due to the size of disk drive technology in
18972-440: The source code in obfuscated form, such as in cases in which the author is less willing to make the source code available. The consensus was that while unethical, it was not considered a violation. The issue was clarified when the license was altered with v2 to require that the "preferred" version of the source code be made available. The GPL was designed as a license , rather than a contract. In some common law jurisdictions,
19125-575: The source code to their customers (including MIT). However, the policy prohibited MIT staff from distributing the Symbolics version of the software to others. With the end of open collaboration came the end of the MIT hacker community. As a reaction to this, Stallman initiated the GNU project to make a new community. Eventually, Copyleft and the GNU General Public License would ensure that
19278-490: The stored-program computer was laid out by Alan Turing in his 1936 paper. In 1945, Turing joined the National Physical Laboratory and began work on developing an electronic stored-program digital computer. His 1945 report "Proposed Electronic Calculator" was the first specification for such a device. John von Neumann at the University of Pennsylvania also circulated his First Draft of a Report on
19431-443: The success of digital electronic computers had spelled the end for most analog computing machines, but analog computers remained in use during the 1950s in some specialized applications such as education ( slide rule ) and aircraft ( control systems ). Claude Shannon 's 1937 master's thesis laid the foundations of digital computing, with his insight of applying Boolean algebra to the analysis and synthesis of switching circuits being
19584-417: The terms of GPLv1 could be combined with software under more permissive terms, as this would not change the terms under which the whole could be distributed. However, software distributed under GPLv1 could not be combined with software distributed under a more restrictive license, as this would conflict with the requirement that the whole be distributable under the terms of GPLv1. According to Richard Stallman,
19737-402: The time. Central processing unit (CPU) clock speed varied depending on which instruction was being executed, but was typically around 5 MHz. Many Lisp primitives could be executed in a single clock cycle . Disk input/output (I/O) was handled by multitasking at the microcode level. A 68000 processor (termed the front-end processor , (FEP)) started the main computer up, and handled
19890-446: The two main methods by which software distributors restricted the freedoms that define free software. The first problem was that distributors might publish only binary files that are executable, but not readable or modifiable by humans. To prevent this, GPLv1 stated that copying and distributing copies of any portion of the program must also make the human-readable source code available under the same licensing terms. The second problem
20043-412: The versatility and accuracy of modern digital computers. The first modern analog computer was a tide-predicting machine , invented by Sir William Thomson (later to become Lord Kelvin) in 1872. The differential analyser , a mechanical analog computer designed to solve differential equations by integration using wheel-and-disc mechanisms, was conceptualized in 1876 by James Thomson , the elder brother of
20196-459: The work and all derivatives. Many distributors of GPL licensed programs bundle the source code with the executables . An alternative method of satisfying the copyleft is to provide a written offer to provide the source code on a physical medium (such as a CD) upon request. In practice, many GPL licensed programs are distributed over the Internet, and the source code is made available over FTP or HTTP . For Internet distribution, this complies with
20349-510: The written offer to obtain the source code that the user got when they received the pre-compiled binary under the GPL. The second section of version 2 and the fifth section of version 3 also require giving "all recipients a copy of this License along with the Program". Version 3 of the license allows making the source code available in additional ways in fulfillment of the seventh section. These include downloading source code from an adjacent network server or by peer-to-peer transmission, provided that
20502-660: Was a computer manufacturer headquartered in Cambridge, Massachusetts , and later in Concord, Massachusetts , with manufacturing facilities in Chatsworth, California (a suburban section of Los Angeles ). Its first CEO, chairman, and founder was Russell Noftsker . Symbolics designed and manufactured a line of Lisp machines , single-user computers optimized to run the programming language Lisp . Symbolics also made significant advances in software technology, and offered one of
20655-406: Was a 16-transistor chip built by Fred Heiman and Steven Hofstein at RCA in 1962. General Microelectronics later introduced the first commercial MOS IC in 1964, developed by Robert Norman. Following the development of the self-aligned gate (silicon-gate) MOS transistor by Robert Kerwin, Donald Klein and John Sarace at Bell Labs in 1967, the first silicon-gate MOS IC with self-aligned gates
20808-403: Was also used to create a few computer-animated movies and was used for some popular movies. Computer A computer is a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations ( computation ). Modern digital electronic computers can perform generic sets of operations known as programs . These programs enable computers to perform
20961-625: Was an early example. Later portables such as the Osborne 1 and Compaq Portable were considerably lighter but still needed to be plugged in. The first laptops, such as the Grid Compass , removed this requirement by incorporating batteries – and with the continued miniaturization of computing resources and advancements in portable battery life, portable computers grew in popularity in the 2000s. The same developments allowed manufacturers to integrate computing resources into cellular mobile phones by
21114-537: Was built with 2000 relays , implementing a 22 bit word length that operated at a clock frequency of about 5–10 Hz . Program code was supplied on punched film while data could be stored in 64 words of memory or supplied from the keyboard. It was quite similar to modern machines in some respects, pioneering numerous advances such as floating-point numbers . Rather than the harder-to-implement decimal system (used in Charles Babbage 's earlier design), using
21267-690: Was called Lisp Machine Lisp at MIT. Symbolics used the name ZetaLisp. Symbolics later wrote new software in Symbolics Common Lisp , its version of the Common Lisp standard. In the late 1980s (2 years later than planned), the Ivory family of single-chip Lisp Machine processors superseded the G-Machine 3650, 3620, and 3630 systems. The Ivory 390k transistor VLSI implementation designed in Symbolics Common Lisp using NS,
21420-511: Was delivered to the University of Manchester in February 1951. At least seven of these later machines were delivered between 1953 and 1957, one of them to Shell labs in Amsterdam . In October 1947 the directors of British catering company J. Lyons & Company decided to take an active role in promoting the commercial development of computers. Lyons's LEO I computer, modelled closely on
21573-443: Was developed by Federico Faggin at Fairchild Semiconductor in 1968. The MOSFET has since become the most critical device component in modern ICs. The development of the MOS integrated circuit led to the invention of the microprocessor , and heralded an explosion in the commercial and personal use of computers. While the subject of exactly which device was the first microprocessor is contentious, partly due to lack of agreement on
21726-825: Was developed in the late 16th century and found application in gunnery, surveying and navigation. The planimeter was a manual instrument to calculate the area of a closed figure by tracing over it with a mechanical linkage. The slide rule was invented around 1620–1630, by the English clergyman William Oughtred , shortly after the publication of the concept of the logarithm . It is a hand-operated analog computer for doing multiplication and division. As slide rule development progressed, added scales provided reciprocals, squares and square roots, cubes and cube roots, as well as transcendental functions such as logarithms and exponentials, circular and hyperbolic trigonometry and other functions . Slide rules with special scales are still used for quick performance of routine calculations, such as
21879-439: Was introduced at the same time and numbered with version 2 to show that both were complementary. The version numbers diverged in 1999 when version 2.1 of the LGPL was released, which renamed it the GNU Lesser General Public License to reflect its place in the philosophy. The GPLv2 was also modified to refer to the new name of the LGPL, but its version number remained the same, resulting in the original GPLv2 not being recognised by
22032-449: Was invented by Abi Bakr of Isfahan , Persia in 1235. Abū Rayhān al-Bīrūnī invented the first mechanical geared lunisolar calendar astrolabe, an early fixed- wired knowledge processing machine with a gear train and gear-wheels, c. 1000 AD . The sector , a calculating instrument used for solving problems in proportion, trigonometry , multiplication and division, and for various functions, such as squares and cube roots,
22185-529: Was later renamed ZetaLisp , to distinguish the Symbolics' product from other vendors who had also licensed the MIT software. Symbolics' Zmacs text editor, a variant of Emacs , was implemented in a text-processing package named ZWEI , an acronym for Zwei was Eine initially , with Eine being an acronym for Eine Is Not Emacs . Both are recursive acronyms and puns on the German words for one ( eins , eine ) and two ( zwei ). The Lisp Machine system software
22338-477: Was made of germanium . Noyce's monolithic IC was fabricated using the planar process , developed by his colleague Jean Hoerni in early 1959. In turn, the planar process was based on Carl Frosch and Lincoln Derick work on semiconductor surface passivation by silicon dioxide. Modern monolithic ICs are predominantly MOS ( metal–oxide–semiconductor ) integrated circuits, built from MOSFETs (MOS transistors). The earliest experimental MOS IC to be fabricated
22491-643: Was most likely a form of tally stick . Later record keeping aids throughout the Fertile Crescent included calculi (clay spheres, cones, etc.) which represented counts of items, likely livestock or grains, sealed in hollow unbaked clay containers. The use of counting rods is one example. The abacus was initially used for arithmetic tasks. The Roman abacus was developed from devices used in Babylonia as early as 2400 BCE. Since then, many other forms of reckoning boards or tables have been invented. In
22644-434: Was not Turing-complete. Nine Mk II Colossi were built (The Mk I was converted to a Mk II making ten machines in total). Colossus Mark I contained 1,500 thermionic valves (tubes), but Mark II with 2,400 valves, was both five times faster and simpler to operate than Mark I, greatly speeding the decoding process. The ENIAC (Electronic Numerical Integrator and Computer) was the first electronic programmable computer built in
22797-426: Was that distributors might add restrictions, either to the license or by combining the software with other software that had other restrictions on distribution. The union of two sets of restrictions would apply to the combined work, thus adding unacceptable constrictions. To prevent this, GPLv1 stated that modified versions, as a whole, had to be distributed under the terms of GPLv1. Therefore, software distributed under
22950-632: Was then copyrighted by MIT, and was licensed to both Symbolics and LMI. Until 1981, Symbolics shared all its copyrighted enhancements to the source code with MIT and kept it on an MIT server. According to Richard Stallman , Symbolics engaged in a business tactic in which it forced MIT to make all Symbolics' copyrighted fixes and improvements to the Lisp Machine OS available only to Symbolics (and MIT but not to Symbolics competitors), and thereby choke off its competitor LMI, which at that time had insufficient resources to independently maintain or develop
23103-682: Was to be released shortly after the Ivory. It was designed by Ron Lebel's group at the Symbolics Westwood office. However, the project was canceled the day it was supposed to tape out. As quickly as the commercial AI boom of the mid-1980s had propelled Symbolics to success, the AI Winter of the late 1980s and early 1990s, combined with the slowdown of the Ronald Reagan administration's Strategic Defense Initiative , popularly termed Star Wars , missile defense program, for which
23256-594: Was to produce one license that could be used for any project, thus making it possible for many projects to share code. The second version of the license, version 2, was released in 1991. Over the following 15 years, members of the free software community became concerned over problems in the GPLv2 license that could let someone exploit GPL-licensed software in ways contrary to the license's intent. These problems included tivoization (the inclusion of GPL-licensed software in hardware that refuses to run modified versions of its software), compatibility issues similar to those of
23409-480: Was written by Richard Stallman in 1989, for use with programs released as part of the GNU project. It was based on a unification of similar licenses used for early versions of GNU Emacs (1985), the GNU Debugger , and the GNU C Compiler . These licenses contained similar provisions to the modern GPL, but were specific to each program, rendering them incompatible, despite being the same license. Stallman's goal
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