Unix is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, development starting in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, others. Intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Microsoft, IBM, Sun Microsystems. In the early 1990s, AT&T sold its rights in Unix to Novell, which sold its Unix business to the Santa Cruz Operation in 1995; the UNIX trademark passed to The Open Group, a neutral industry consortium, which allows the use of the mark for certified operating systems that comply with the Single UNIX Specification. As of 2014, the Unix version with the largest installed base is Apple's macOS. Unix systems are characterized by a modular design, sometimes called the "Unix philosophy"; this concept entails that the operating system provides a set of simple tools that each performs a limited, well-defined function, with a unified filesystem as the main means of communication, a shell scripting and command language to combine the tools to perform complex workflows.
Unix distinguishes itself from its predecessors as the first portable operating system: the entire operating system is written in the C programming language, thus allowing Unix to reach numerous platforms. Unix was meant to be a convenient platform for programmers developing software to be run on it and on other systems, rather than for non-programmers; the system grew larger as the operating system started spreading in academic circles, as users added their own tools to the system and shared them with colleagues. At first, Unix was not designed to be multi-tasking. Unix gained portability, multi-tasking and multi-user capabilities in a time-sharing configuration. Unix systems are characterized by various concepts: the use of plain text for storing data; these concepts are collectively known as the "Unix philosophy". Brian Kernighan and Rob Pike summarize this in The Unix Programming Environment as "the idea that the power of a system comes more from the relationships among programs than from the programs themselves".
In an era when a standard computer consisted of a hard disk for storage and a data terminal for input and output, the Unix file model worked quite well, as I/O was linear. In the 1980s, non-blocking I/O and the set of inter-process communication mechanisms were augmented with Unix domain sockets, shared memory, message queues, semaphores, network sockets were added to support communication with other hosts; as graphical user interfaces developed, the file model proved inadequate to the task of handling asynchronous events such as those generated by a mouse. By the early 1980s, users began seeing Unix as a potential universal operating system, suitable for computers of all sizes; the Unix environment and the client–server program model were essential elements in the development of the Internet and the reshaping of computing as centered in networks rather than in individual computers. Both Unix and the C programming language were developed by AT&T and distributed to government and academic institutions, which led to both being ported to a wider variety of machine families than any other operating system.
Under Unix, the operating system consists of many libraries and utilities along with the master control program, the kernel. The kernel provides services to start and stop programs, handles the file system and other common "low-level" tasks that most programs share, schedules access to avoid conflicts when programs try to access the same resource or device simultaneously. To mediate such access, the kernel has special rights, reflected in the division between user space and kernel space - although in microkernel implementations, like MINIX or Redox, functions such as network protocols may run in user space; the origins of Unix date back to the mid-1960s when the Massachusetts Institute of Technology, Bell Labs, General Electric were developing Multics, a time-sharing operating system for the GE-645 mainframe computer. Multics featured several innovations, but presented severe problems. Frustrated by the size and complexity of Multics, but not by its goals, individual researchers at Bell Labs started withdrawing from the project.
The last to leave were Ken Thompson, Dennis Ritchie, Douglas McIlroy, Joe Ossanna, who decided to reimplement their experiences in a new project of smaller scale. This new operating system was without organizational backing, without a name; the new operating system was a single-tasking system. In 1970, the group coined the name Unics for Uniplexed Information and Computing Service, as a pun on Multics, which stood for Multiplexed Information and Computer Services. Brian Kernighan takes credit for the idea, but adds that "no one can remember" the origin of the final spelling Unix. Dennis Ritchie, Doug McIlroy, Peter G. Neumann credit Kernighan; the operating system was written in assembly language, but in 1973, Version 4 Unix was rewritten in C. Version 4 Unix, still had many PDP-11 dependent codes, is not suitable for porting; the first port to other platform was made five years f
Jerry Eugene Pournelle was an American polymath: scientist in the area of operations research and human factors research, science fiction writer, essayist and one of the first bloggers. In the 1960s and early 1970s he worked in the aerospace industry, but focused on his writing career. In an obituary in gizmodo, he is described as "a tireless ambassador for the future."Pournelle is known for writing hard science fiction, received multiple awards for his writing. In addition to his solo writing, he wrote several novels with collaborators, most notably Larry Niven. Pournelle served a term as President of the Science Fantasy Writers of America. Pournelle's journalism focused on the computer industry and space exploration. From the 1970s until the early 1990s, he contributed to the computer magazine Byte, writing from the viewpoint of an intelligent user, with the oft-cited credo, “We do this stuff so you won’t have to.” He created one of the first blogs, entitled "Chaos Manor", which included commentary about politics, computer technology, space technology, science fiction.
Pournelle was known for his paleoconservative political views, which were sometimes expressed in his fiction. He was one of the founders of the Citizens' Advisory Council on National Space Policy, which developed some of the Reagan Administration's space initiatives, including the earliest versions of what would become the Strategic Defense Initiative. Pournelle was born in Shreveport, the seat of Caddo Parish in northwestern Louisiana, lived with his family in Capleville, Tennessee, an unincorporated area near Memphis, TN. Percival Pournelle, his father, was a radio advertising executive and general manager of several radio stations. Ruth Pournelle, his mother, was a teacher, although during World War II, she worked in a munitions factory, he attended first grade at St. Anne’s Elementary School which had two grades to a classroom, was located in Memphis. Beginning with third grade, he attended Coleville Consolidated Elementary School, which had about 25 pupils per grade and four rooms and four teachers for 8 grades, was located in Coleville, near Memphis, TN.
Pournelle attended high school at Christian Brothers College in Memphis, TN, which despite its name, was a High School at that time. He served in the U. S. Army during the Korean War. In 1953–54, after his military service, Pournelle attended the State University of Iowa in Iowa City. Subsequently, he studied at the University of Washington, where he received a B. S. in psychology on June 11, 1955. S. in psychology on March 21, 1958. D. in political science in March 1964. The thesis for his M. S. is titled "Behavioural observations of the effects of personality needs and leadership in small discussion groups", is dated 1957. Pournelle's PhD dissertation is titled "The American political continuum. Pournelle married Roberta Jane Isdell in 1969. In 2008, Pournelle battled a brain tumor, which appeared to respond favorably to radiation treatment. An August 28, 2008 report on his weblog claimed. Pournelle suffered a stroke for which he was hospitalized for a time. By June 2015, he was writing again. Pournelle died in his sleep of heart failure at his home in Studio City, California, on September 8, 2017.
Pournelle was raised a Unitarian. He converted to Roman Catholicism while attending Christian Brothers College, despite its name, was a High School run by the De La Salle Christian Brothers and located in Memphis, TN. Pournelle was introduced to Malthusian principles upon reading the book Road to Survival by the ecologist William Vogt, who depicted an Earth denuded of species other than humans, all of them headed for squalor. Concerned about the Malthusian dangers of human overpopulation, considering the position of the Roman Catholic church on contraception to be untenable, he left the Catholic church while an undergraduate at State University of Iowa. Pournelle returned to religion, for a number of years was a high church Anglican, in part because Anglican theology was identical to Catholic theology, with the exception that the Anglicans accepted as moral the use of birth control. Pournelle returned to the Roman Catholic church, as his other beliefs were consistent with the Catholic communion, although he did not agree with the Church's position on birth control.
Notably, he opposed having the government require that Catholic institutions provide access to birth control or abortion. In his online blog, the view from Chaos Manor, he exhibited familiarity with and admiration for Catholic theology quoting Catholic liturgical phrases. Pournelle describes Sunday church attendance as part of his family's routine. Upon his death his family arranged at noon Saturday, 16 September 2017, at St. Francis De Sales Church. Pournelle was an intellectual protégé of Stefan T. Possony. Pournelle wrote numerous publications including The Strategy of Technology; the Strategy has been used as a textbook at the United States Military Academy, the United States Air Force Academy, the Air War College, the National War College. In 1949, while conducting operations research at Boeing, he envisioned a weapon consisting of massive tungsten rods dropped from high above the Earth; these super-dense, super-fast kinetic en
Recursion occurs when a thing is defined in terms of itself or of its type. Recursion is used in a variety of disciplines ranging from linguistics to logic; the most common application of recursion is in mathematics and computer science, where a function being defined is applied within its own definition. While this defines an infinite number of instances, it is done in such a way that no loop or infinite chain of references can occur. In mathematics and computer science, a class of objects or methods exhibit recursive behavior when they can be defined by two properties: A simple base case —a terminating scenario that does not use recursion to produce an answer A set of rules that reduce all other cases toward the base caseFor example, the following is a recursive definition of a person's ancestors: One's parents are one's ancestors; the ancestors of one's ancestors are one's ancestors. The Fibonacci sequence is a classic example of recursion: Fib = 0 as base case 1, Fib = 1 as base case 2, For all integers n > 1, Fib:= Fib + Fib.
Many mathematical axioms are based upon recursive rules. For example, the formal definition of the natural numbers by the Peano axioms can be described as: 0 is a natural number, each natural number has a successor, a natural number. By this base case and recursive rule, one can generate the set of all natural numbers. Recursively defined mathematical objects include functions and fractals. There are various more tongue-in-cheek "definitions" of recursion. Recursion is the process a procedure goes through when one of the steps of the procedure involves invoking the procedure itself. A procedure that goes through recursion is said to be'recursive'. To understand recursion, one must recognize the distinction between a procedure and the running of a procedure. A procedure is a set of steps based on a set of rules; the running of a procedure involves following the rules and performing the steps. An analogy: a procedure is like a written recipe. Recursion is related to, but not the same as, a reference within the specification of a procedure to the execution of some other procedure.
For instance, a recipe might refer to cooking vegetables, another procedure that in turn requires heating water, so forth. However, a recursive procedure is where one of its steps calls for a new instance of the same procedure, like a sourdough recipe calling for some dough left over from the last time the same recipe was made; this creates the possibility of an endless loop. If properly defined, a recursive procedure is not easy for humans to perform, as it requires distinguishing the new from the old invocation of the procedure. For this reason recursive definitions are rare in everyday situations. An example could be the following procedure to find a way through a maze. Proceed forward until reaching either an exit or a branching point. If the point reached is an exit, terminate. Otherwise try each branch in turn, using the procedure recursively. Whether this defines a terminating procedure depends on the nature of the maze: it must not allow loops. In any case, executing the procedure requires recording all explored branching points, which of their branches have been exhaustively tried.
Linguist Noam Chomsky among many others has argued that the lack of an upper bound on the number of grammatical sentences in a language, the lack of an upper bound on grammatical sentence length, can be explained as the consequence of recursion in natural language. This can be understood in terms of a recursive definition of a syntactic category, such as a sentence. A sentence can have a structure in which what follows the verb is another sentence: Dorothy thinks witches are dangerous, in which the sentence witches are dangerous occurs in the larger one. So a sentence can be defined recursively as something with a structure that includes a noun phrase, a verb, optionally another sentence; this is just a special case of the mathematical definition of recursion. This provides a way of understanding the creativity of language—the unbounded number of grammatical sentences—because it predicts that sentences can be of arbitrary length: Dorothy thinks that Toto suspects that Tin Man said that.... There are many structures apart from sentences that can be defined recursively, therefore many ways in which a sentence can embed instances of one
The Amiga is a family of personal computers introduced by Commodore in 1985. The original model was part of a wave of 16- and 32-bit computers that featured 256 KB or more of RAM, mouse-based GUIs, improved graphics and audio over 8-bit systems; this wave included the Atari ST—released the same year—Apple's Macintosh, the Apple IIGS. Based on the Motorola 68000 microprocessor, the Amiga differed from its contemporaries through the inclusion of custom hardware to accelerate graphics and sound, including sprites and a blitter, a pre-emptive multitasking operating system called AmigaOS; the Amiga 1000 was released in July 1985, but a series of production problems kept it from becoming available until early 1986. The best selling model, the Amiga 500, was introduced in 1987 and became one of the leading home computers of the late 1980s and early 1990s with four to six million sold; the A3000, introduced in 1990, started the second generation of Amiga systems, followed by the A500+, the A600 in March 1992.
As the third generation, the A1200 and the A4000 were released in late 1992. The platform became popular for gaming and programming demos, it found a prominent role in the desktop video, video production, show control business, leading to video editing systems such as the Video Toaster. The Amiga's native ability to play back multiple digital sound samples made it a popular platform for early tracker music software; the powerful processor and ability to access several megabytes of memory enabled the development of several 3D rendering packages, including LightWave 3D, Aladdin4D, TurboSilver and Traces, a predecessor to Blender. Although early Commodore advertisements attempt to cast the computer as an all-purpose business machine when outfitted with the Amiga Sidecar PC compatibility add-on, the Amiga was most commercially successful as a home computer, with a wide range of games and creative software. Poor marketing and the failure of the models to repeat the technological advances of the first systems meant that the Amiga lost its market share to competing platforms, such as the fourth generation game consoles and the dropping prices of IBM PC compatibles which gained 256-color VGA graphics in 1987.
Commodore went bankrupt in April 1994 after the Amiga CD32 model failed in the marketplace. Since the demise of Commodore, various groups have marketed successors to the original Amiga line, including Genesi, Eyetech, ACube Systems Srl and A-EON Technology. AmigaOS has influenced replacements and compatible systems such as MorphOS, AmigaOS 4 and AROS. "The Amiga was so far ahead of its time that nobody—including Commodore's marketing department—could articulate what it was all about. Today, it's obvious the Amiga was the first multimedia computer, but in those days it was derided as a game machine because few people grasped the importance of advanced graphics and video. Nine years vendors are still struggling to make systems that work like 1985 Amigas." Jay Miner joined Atari in the 1970s to develop custom integrated circuits, led development of the Atari 2600's TIA. As soon as its development was complete, the team began developing a much more sophisticated set of chips, CTIA, ANTIC and POKEY, that formed the basis of the Atari 8-bit family.
With the 8-bit line's launch in 1979, the team once again started looking at a next generation chipset. Nolan Bushnell had sold the company to Warner Communications in 1978, the new management was much more interested in the existing lines than development of new products that might cut into their sales. Miner wanted to start work with the new Motorola 68000, but management was only interested in another 6502 based system. Miner left the company, for a time, the industry. In 1979, Larry Kaplan founded Activision. In 1982, Kaplan was approached by a number of investors. Kaplan hired Miner to run the hardware side of the newly formed company, "Hi-Toro"; the system was code-named "Lorraine" in keeping with Miner's policy of giving systems female names, in this case the company president's wife, Lorraine Morse. When Kaplan left the company late in 1982, Miner was promoted to head engineer and the company relaunched as Amiga Corporation. A breadboard prototype was completed by late 1983, shown at the January 1984 Consumer Electronics Show.
At the time, the operating system was not ready, so the machine was demonstrated with the Boing Ball demo. A further developed version of the system was demonstrated at the June 1984 CES and shown to many companies in hopes of garnering further funding, but found little interest in a market, in the final stages of the North American video game crash of 1983. In March, Atari expressed a tepid interest in Lorraine for its potential use in a games console or home computer tentatively known as the 1850XLD, but the talks were progressing and Amiga was running out of money. A temporary arrangement in June led to a $500,000 loan from Atari to Amiga to keep the company going; the terms required the loan to be repaid at the end of the month, otherwise Amiga would forfeit the Lorraine design to Atari. During 1983, Atari lost over $1 million a week, due to the combined effects of the crash and the ongoing price war in the home computer market. By the end of the year, Warner was desperate to sell the company.
In January 1984, Jack Tramiel resigned from Commodore due to internal battles over the future direction of the company. A number of Commodore employees followed him to Tramiel Technology; this included a number of the senior technical staff, where they began development of a 68000-based machine of the
The Atari ST is a line of home computers from Atari Corporation and the successor to the Atari 8-bit family. The initial ST model, the 520ST, saw limited release in April–June 1985 and was available in July; the Atari ST is the first personal computer to come with a bitmapped color GUI, using a version of Digital Research's GEM released in February 1985. The 1040ST, released in 1986, is the first personal computer to ship with a megabyte of RAM in the base configuration and the first with a cost-per-kilobyte of less than US$1; the Atari ST is part of a mid-1980s generation of home computers that have 16 or 32-bit processors, 256 KB or more of RAM, mouse-controlled graphical user interfaces. This generation includes the Macintosh, Commodore Amiga, Apple IIGS, and, in certain markets, the Acorn Archimedes. "ST" stands for "Sixteen/Thirty-two", which refers to the Motorola 68000's 16-bit external bus and 32-bit internals. The ST was sold with the less expensive monochrome monitor; the system's two color graphics modes are only available on the former while the highest-resolution mode needs the monochrome monitor.
In some markets Germany, the machine gained a strong foothold as a small business machine for CAD and desktop publishing work. Thanks to its built-in MIDI ports, the ST enjoyed success for running music-sequencer software and as a controller of musical instruments among amateurs and well-known musicians alike; the ST was superseded by the Atari STE, Atari TT, Atari MEGA STE, Falcon computers. The Atari ST was born from the rivalry between home-computer makers Atari, Inc. and Commodore International. Jay Miner, one of the original designers for the custom chips found in the Atari 2600 and Atari 8-bit family, tried to convince Atari management to create a new chipset for a video game console and computer; when his idea was rejected, Miner left Atari to form a small think tank called Hi-Toro in 1982 and began designing the new "Lorraine" chipset. The company, renamed Amiga Corporation, was pretending to sell video game controllers to deceive competition while it developed a Lorraine-based computer.
Amiga ran out of capital to complete Lorraine's development, Atari, owned by Warner Communications, paid Amiga to continue development work. In return Atari received exclusive use of the Lorraine design for one year as a video game console. After one year Atari would have the right to add a keyboard and market the complete computer, designated the 1850XLD; as Atari was involved with Disney at the time, it was code-named "Mickey", the 256K memory expansion board was codenamed "Minnie". After leaving Commodore International in January 1984, Jack Tramiel formed Tramel Technology with his sons and other ex-Commodore employees and, in April, began planning a new computer; the company considered the National Semiconductor NS320xx microprocessor but was disappointed with its performance. This started the move to the 68000; the lead designer of the Atari ST was ex-Commodore employee Shiraz Shivji, who had worked on the Commodore 64's development. Atari in mid-1984 was losing about a million dollars per day.
Interested in Atari's overseas manufacturing and worldwide distribution network for his new computer, Tramiel negotiated with Warner in May and June 1984. He bought Atari's Consumer Division in July; as executives and engineers left Commodore to join Tramiel's new Atari Corporation, Commodore responded by filing lawsuits against four former engineers for theft of trade secrets. The Tramiels did not purchase the employee contracts when they bought the assets of Atari Inc. so one of their first acts was to interview Atari Inc. employees to decide whom to hire at what was a brand new company. This company was called TTL renamed to Atari Corp. At the time of the purchase of Atari Inc's assets, there were 900 employees remaining from a high point of 10,000. After the interviews 100 employees were hired to work at Atari Corp. At one point a custom sound processor called AMY was a planned component for the new ST computer design, but the chip needed more time to complete, so AMY was dropped in favor of an off-the-shelf Yamaha sound chip.
It was during this time in late July/early August that Leonard Tramiel discovered the original Amiga contract, which required Amiga Corporation to deliver the Lorraine chipset to Atari on June 30, 1984. Amiga Corp. had sought more monetary support from investors in spring 1984. Having heard rumors that Tramiel was negotiating to buy Atari, Amiga Corp. entered into discussions with Commodore. The discussions led to Commodore wanting to purchase Amiga Corporation outright, which Commodore believed would cancel any outstanding contracts, including Atari's. Instead of Amiga Corp. delivering Lorraine to Atari, Commodore delivered a check of $500,000 to Atari on Amiga's behalf, in effect returning the funds Atari invested into Amiga for the chipset. Tramiel countersued Amiga Corp. on August 13, 1984. He sought an injunction to bar Amiga from producing anything with its technology. At Commodore, the Amiga team was in limbo during the summer of 1984 because of the lawsuit. No word on the status of the chipset, the Lorraine computer, or the team's fate was known.
In the fall of 1984, Commodore informed the team that the Lorraine project was active again, the chipset was to be improved, the operating system developed, the hardware design completed. While Commodore announced the Amiga 1000 with the Lorraine chipset in July 1985, the delay gave Atari, with its ma
The IBM Personal Computer Basic shortened to IBM BASIC, is a programming language first released by IBM with the IBM Personal Computer in 1981. IBM released four different versions of the Microsoft BASIC interpreter, licensed from Microsoft for the PC and PCjr, they are known as Cassette BASIC, Disk BASIC, Advanced BASIC, Cartridge BASIC. Versions of Disk BASIC and Advanced BASIC were included with IBM PC DOS up to PC DOS 4. In addition to the features of an ANSI standard BASIC, the IBM versions offered support for the graphics and sound hardware of the IBM PC line. Source code could be typed in with a full screen editor, limited facilities were provided for rudimentary program debugging. IBM released a version of the Microsoft BASIC compiler for the PC, concurrently with the release of PC DOS 1.10 in 1982. IBM licensed Microsoft BASIC for the PC despite having its own version for the company's mainframes. Don Estridge said, "Microsoft BASIC had hundreds of thousands of users around the world.
How are you going to argue with that?" IBM Cassette BASIC came in 32 kilobytes of read-only memory, separate from the 8 KB BIOS ROM of the original IBM PC, did not require an operating system to run. Cassette BASIC provided the default user interface invoked by the BIOS through INT 18h if there was no floppy disk drive installed, or if the boot code did not find a bootable floppy disk at power up; the name Cassette BASIC came from its use of cassette tapes rather than floppy disks to store programs and data. Cassette BASIC was built into the ROMs of the original PC and XT, early models in the PS/2 line, it only supported loading and saving programs to the IBM cassette tape interface, unavailable on models after the original Model 5150. The entry-level version of the 5150 came with just 16 KB of random-access memory, sufficient to run Cassette BASIC. However, Cassette BASIC was used because few PCs were sold without a disk drive, most were sold with PC DOS and sufficient RAM to at least run Disk BASIC—many could run Advanced BASIC as well.
There were three versions of Cassette BASIC: C1.00, C1.10, C1.20. IBM Disk BASIC was included in the original IBM PC DOS; because it uses the 32 KB Cassette BASIC ROM, BASIC. COM did not run on highly compatible PC clones such as the Compaq Portable; the name Disk BASIC came from its use of floppy disks as well as cassette tapes to store programs and data. Disk-based code corrected errata in the ROM-resident code and added floppy disk and serial port support. Disk BASIC could be identified by its use of the letter D preceding the version number, it added disk support and some features lacking in Cassette BASIC, but did not include the extended sound/graphics functions of BASICA. The primary purpose of Disk BASIC was as a "lite" version for IBM PCs with only 48K of memory: BASIC. COM would have about 23K free for user code, whereas BASICA would only have about 17K. By 1986, all new PCs shipped with at least 256k and DOS versions after 3.00 reduced Disk BASIC to only a small stub that called BASICA.
COM for compatibility with batch files. With all this excess RAM, BASIC would still only allocate and manage just under 61K for user programs. IBM Advanced BASIC was included in the original IBM PC DOS, required the ROM-resident code of Cassette BASIC, it added functions such as diskette file access, storing programs on disk, monophonic sound using the PC's built-in speaker, graphics functions to set and clear pixels, draw lines and circles, set colors, event handling for communications and joystick presses. BASICA would not run on non-IBM computers or IBM models, since those lack the needed ROM BASIC. BASICA versions were the same as their respective DOS, beginning with v1.00 and ending with v3.30. The early versions of BASICA did not support subdirectories and some graphics commands functioned differently; as an example, if the LINE statement was used to draw lines that trailed off-screen, BASIC would intersect them with the nearest adjacent line while in BASIC 2.x and up, they went off the screen and did not intersect.
The PAINT command in BASIC 1.x begins filling at the coordinate specified and expands outward in alternating up and down directions while in BASIC 2.x it fills everything below the starting coordinate and after finishing, everything above it. BASIC 1.x's PAINT command makes use of the system stack for storage and when filling in complex areas, it was possible to produce an OVERFLOW error. To remedy this, the CLEAR statement can be used to expand BASIC's stack. BASIC 2.x does not use the stack when thus is free of this problem. Compaq BASIC 1.13 was the first standalone BASIC for the PC as well as the only version of BASIC besides IBM BASICA 1.00 and 1.10 to use FCBs and include the original LINE statement with intersecting lines. Early versions of PC DOS included several sample BASIC programs demonstrating the capabilities of the PC, including the BASICA game DONKEY. BAS. GW-BASIC is identical to BASICA, with the exception of including the Cassette BASIC code in the program, thus allowing it to run on non-IBM computers and IBM models that lack Cassette BASIC in ROM.
A ROM cartridge version of BASIC was only available on the IBM PCjr and supported the additional graphics modes and sound capa
BASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use. In 1964, John G. Kemeny and Thomas E. Kurtz designed the original BASIC language at Dartmouth College, they wanted to enable students in fields other than mathematics to use computers. At the time, nearly all use of computers required writing custom software, something only scientists and mathematicians tended to learn. In addition to the language itself and Kurtz developed the Dartmouth Time Sharing System, which allowed multiple users to edit and run BASIC programs at the same time; this general model became popular on minicomputer systems like the PDP-11 and Data General Nova in the late 1960s and early 1970s. Hewlett-Packard produced an entire computer line for this method of operation, introducing the HP2000 series in the late 1960s and continuing sales into the 1980s. Many early video games trace their history to one of these versions of BASIC; the emergence of early microcomputers in the mid-1970s led to the development of the original Microsoft BASIC in 1975.
Due to the tiny main memory available on these machines 4 kB, a variety of Tiny BASIC dialects were created. BASIC was available for any system of the era, became the de facto programming language for the home computer systems that emerged in the late 1970s; these machines always had a BASIC installed by default in the machine's firmware or sometimes on a ROM cartridge. BASIC fell from use during the 1980s as newer machines with far greater capabilities came to market and other programming languages became tenable. In 1991, Microsoft released Visual Basic, combining a updated version of BASIC with a visual forms builder; this reignited use of the language and "VB" remains a major programming language in the form of VB. NET. John G. Kemeny was the math department chairman at Dartmouth College, on his reputation as an innovator in math teaching, in 1959 the school won an Alfred P. Sloan Foundation award for $500,000 to build a new department building. Thomas E. Kurtz had joined the department in 1956, from the 1960s they agreed on the need for programming literacy among students outside the traditional STEM fields.
Kemeny noted that “Our vision was that every student on campus should have access to a computer, any faculty member should be able to use a computer in the classroom whenever appropriate. It was as simple as that."Kemeny and Kurtz had made two previous experiments with simplified languages, DARSIMCO and DOPE. These did not progress past a single freshman class. New experiments using Fortran and ALGOL followed, but Kurtz concluded these languages were too tricky for what they desired; as Kurtz noted, Fortran had numerous oddly-formed commands, notably an "almost impossible-to-memorize convention for specifying a loop:'DO 100, I = 1, 10, 2'. Is it'1, 10, 2' or'1, 2, 10', is the comma after the line number required or not?"Moreover, the lack of any sort of immediate feedback was a key problem. Kurtz suggested. Small programs would return results in a few seconds; this led to increasing interest in a system using time-sharing and a new language for use by non-STEM students. Kemeny wrote the first version of BASIC.
The acronym BASIC comes from the name of an unpublished paper by Thomas Kurtz. The new language was patterned on FORTRAN II. However, the syntax was changed. For instance, the difficult to remember DO loop was replaced by the much easier to remember FOR I = 1 TO 10 STEP 2, the line number used in the DO was instead indicated by the NEXT I; the cryptic IF statement of Fortran, whose syntax matched a particular instruction of the machine on which it was written, became the simpler IF I=5 THEN GOTO 100. These changes made the language much less idiosyncratic while still having an overall structure and feel similar to the original FORTRAN; the project received a $300,000 grant from the National Science Foundation, used to purchase a GE-225 computer for processing, a Datanet-30 realtime processor to handle the Teletype Model 33 teleprinters used for input and output. A team of a dozen undergraduates worked on the project for about a year, writing both the DTSS system and the BASIC compiler; the main CPU was replaced by a GE-235, still by a GE-635 The first version BASIC language was released on 1 May 1964.
One of the graduate students on the implementation team was Sr. Mary Kenneth Keller, one of the first people in the United States to earn a Ph. D. in computer science and the first woman to do so. BASIC concentrated on supporting straightforward mathematical work, with matrix arithmetic support from its initial implementation as a batch language, character string functionality being added by 1965. Wanting use of the language to become widespread, its designers made the compiler available free of charge, they made it available to high schools in the Hanover, New Hampshire area and put considerable effort into