Fourth Generation

(1972-1984)


The next generation of computer systems saw the use of large scale integration (LSI - 1000 devices per chip) and very large scale integration (VLSI - 100,000 devices per chip) in the construction of computing elements. At this scale entire processors will fit onto a single chip, and for simple systems the entire computer (processor, main memory, and I/O controllers) can fit on one chip. Gate delays dropped to about 1ns per gate.

Semiconductor memories replaced core memories as the main memory in most systems; until this time the use of semiconductor memory in most systems was limited to registers and cache. During this period, high speed vector processors, such as the CRAY 1, CRAY X-MP and CYBER 205 dominated the high performance computing scene. Computers with large main memory, such as the CRAY 2, began to emerge. A variety of parallel architectures began to appear; however, during this period the parallel computing efforts were of a mostly experimental nature and most computational science was carried out on vector processors. Microcomputers and workstations were introduced and saw wide use as alternatives to time-shared mainframe computers.

The First PC

Developments in software include very high level languages such as FP (functional programming) and Prolog (programming in logic). These languages tend to use a declarative programming style as opposed to the imperative style of Pascal, C, FORTRAN, et al. In a declarative style, a programmer gives a mathematical specification of what should be computed, leaving many details of how it should be computed to the compiler and/or runtime system. These languages are not yet in wide use, but are very promising as notations for programs that will run on massively parallel computers (systems with over 1,000 processors). Compilers for established languages started to use sophisticated optimization techniques to improve code, and compilers for vector processors were able to vectorize simple loops (turn loops into single instructions that would initiate an operation over an entire vector).

Two important events marked the early part of the third generation: the development of the C programming language and the UNIX operating system, both at Bell Labs. In 1972, Dennis Ritchie, seeking to meet the design goals of CPL and generalize Thompson's B, developed the C language. Thompson and Ritchie then used C to write a version of UNIX for the DEC PDP-11. This C-based UNIX was soon ported to many different computers, relieving users from having to learn a new operating system each time they change computer hardware. UNIX or a derivative of UNIX is now a de facto standard on virtually every computer system.

An important event in the development of computational science was the publication of the Lax report. In 1982, the US Department of Defense (DOD) and National Science Foundation (NSF) sponsored a panel on Large Scale Computing in Science and Engineering, chaired by Peter D. Lax. The Lax Report stated that aggressive and focused foreign initiatives in high performance computing, especially in Japan, were in sharp contrast to the absence of coordinated national attention in the United States. The report noted that university researchers had inadequate access to high performance computers. One of the first and most visible of the responses to the Lax report was the establishment of the NSF supercomputing centers. Phase I on this NSF program was designed to encourage the use of high performance computing at American universities by making cycles and training on three (and later six) existing supercomputers immediately available. Following this Phase I stage, in 1984-1985 NSF provided funding for the establishment of five Phase II supercomputing centers.

The Phase II centers, located in San Diego (San Diego Supercomputing Center); Illinois (National Center for Supercomputing Applications); Pittsburgh (Pittsburgh Supercomputing Center); Cornell (Cornell Theory Center); and Princeton (John von Neumann Center), have been extremely successful at providing computing time on supercomputers to the academic community. In addition they have provided many valuable training programs and have developed several software packages that are available free of charge. These Phase II centers continue to augment the substantial high performance computing efforts at the National Laboratories, especially the Department of Energy (DOE) and NASA sites.

Year wise summery of development

1972 : Hand-held calculators become popular, making the slide rule obsolete. Intel's 8008, the first 8-bit microprocessor, appears but is soon replaced by the 8080. Nolan Bushnell's Pong video game is so successful that he founds Atari. Dennis Ritchie develops C at Bell Labs, so named because its predecessor was named B. Smalltalk is developed by Xerox PARC's Learning Research Group, based largely on the ideas of Alan Kay. Alain Colmerauer at the University of Marseille develops Prolog, which popularizes key logic programming concepts. Analytic complexity theory develops the idea of NP-completeness, showing that a large class of computing problems, such as the "traveling salesman problem," may be computationally intractable. Wang, VYDEC, and Lexitron all introduce word processing systems. In Wimbledon, England, an experimental computerized axial tomography imager finds a brain tumor in a patient. DEC's PDP 11/45 is introduced, its circuitry encased in chips. Steve Wozniak builds a "blue box" tone generator to make free phone calls and sells them in the dorm at UC Berkeley.

Gary Kildall at Naval Postgraduate School writes PL/1, the first programming language for the Intel 4004 microprocessor. Intel introduces the 8008, an 8 bit microprocessor.

1973: First National Computer Conference (NCC) is held in New York City. IBM settles a lawsuit by Control Data, selling Service Bureau Corporation (SBC) to Control Data. PROLOG language is developed by Alain Comerauer at the University of Marseilles-Luminy, France. R2E markets the MICRAL, the first microcomputer in France. chester disk drives are first introduced by IBM, who uses the term as a code name for its Model 3340 direct-access storage device.

1974 : An article in Radio Electronics describes how to build a "personal minicomputer," the Mark-8. At Xerox PARC, Charles Simonyi writes the first WYSIWYG application, Bravo. A 4-Kbit D-RAM chip becomes commercially available. In Stockholm, chess-playing computer engage in their first tournament. . Intel introduces the 8080, an 8 bit microprocessor that will be used in numerous personal computers. Zilog is formed.

1975: Cray-1 supercomputer is introduced. Homebrew Computer Club, considered the first personal computer users group, is formed. MITS introduces the Altair personal computer, named after a Star Trek episode, A Voyage to Altair. The kit cost $397 for a 256 byte computer. The I/O consisted of switches and lights. It was designed by Ed Roberts and Bill Yates. Microsoft is founded after Bill Gates and Paul Allen adapt and sell BASIC to MITS for the Altair PC. The first computer store opens in Santa Monica, CA. Xerox withdraws from the mainframe computer industry.

1976: First fault-tolerant computer, the T/16, is introduced by Tandem. MYCIN, an expert system to diagnose and treat infectious blood diseases, is developed at Stanford University by E. Shortliffe. NEC System 800 and 900 general-purpose mainframes are introduced. Seymour Cray engineers and delivers Cray 1 with 200,000 freon-cooled ICs and 100 million floating point operations per second (MFLOP) performance. Superminicomputers are introduced by Perkin-Elmer and Gould SEL. Zilog Z-80 chip is introduced.

1977: Apple Computer is founded and introduces the Apple II personal computer. Apple, Commodore, and Tandy begin selling personal computers. DEC introduces its first 32-bit superminicomputer, the VAX-11/780. Datapoint introduces ARC system, the first local area network. First ComputerLand franchise store opens in Morristown, NJ under the name Computer Shack.

1978: SPRINT business service is inaugurated. Texas Instruments introduces the Speak-and-Spell educational toy featuring digital speech synthesis. Total computers in use in the U.S. exceed a half million units. The first COMDEX trade show is held. Intel's first 16-bit processor, the 8086, debuts. 1978.Wordstar is introduced and goes on to become a widely used word processor with CP/M systems and later on DOS computers.Intel's first 16-bit processor, the 8086, debuts.

1979: Benoit Mandelbrot continues his research into fractals by generating a Mandelbrot set, derived from z(n + 1) = z(n) * z(n) - (0). The first electronic spreadsheet program, Don Bricklin's and Bob Franston's VisiCalc, is uneveiled on May 11 and proves to be the "killer app" for early PCs. Motorola introduces the 68000 chip, which will later support the Macintosh. Digital videodisks appear trough the efforts of Sony an Philips. Cellular telephones are tested in Japan and Chicago. Ada language is developed by a team at CII-Honeywell Bull (France) directed by Jean Ichbiah.

1980: Control Data Corporation introduces the Cyber 205 supercomputer. First issue of InfoWorld is published. Microsoft licenses UNIX operating system from Bell Laboratories and introduces its XENIX adaptation. Total computers in use in the U.S. exceed one million units.

1981: Barry Boehm devices Cocomo (Constructive Cost Modell), a software cost-estimation model. Japan grabs a big piece of the chip market by producing chips with 64 Kbits of memory. Xerox introduces a commercial version of the Alto called the Xerox Star. The open-architecture IBM PC is launched in August, signaling to corporate America that desktop computing is going mainstream.

1982: AT&T agrees to give up 22 Bell System companies in settling a 13-year-old lawsuit brought by the Justice Department. Compaq Computer incorporates. Sun Microsystems is founded. Microsoft licenses MS-DOS to 50 microcomputer manufacturers in the first 16 months of availability. Time Magazine names the computer its Man of the Year. U.S. drops IBM antitrust suit begun in 1969.

1983: Compaq ships its first computer in January and sells $111M, the greatest first-year sales in the history of American business. Cray 2 computer introduced with one billion FLOPs (floating point operations per second) performance rating. Lotus 1-2-3 replaces VisiCalc as the spreadsheet software of choice for microcomputers. NEC announces the SX-1 and SX-2 supercomputers. Total computers in use in the U.S. exceed ten million units.

1984: Apple introduces the Macintosh computer. IBM introduces the PC AT (Advanced Technology). IBM merges with Rolm Corp., which becomes a telecommunications subsidiary. The Tandy 1000 personal computer becomes the #1 selling IBM PC-compatible in its first year. MIDI (Musical Instrument Digital Interafce) standards are developed for computers and digital music synthesizers.

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