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IBM 1400 Series

IBM 1400 series

The IBM 1400 series was a family of mid-range buisiness computers that IBM sold in the early 1960s as a replacement for unit record equipment. 1400 machines stored information in magnetic cores as variable length character strings terminated by a special flag. Arithmetic was performed character-by-character. Input and output was on punch card, magnetic tape and high speed line printers. Disk storage was also available Members of the 1400 series included:
- IBM 1401 - 1959
- IBM 1410 - 1960
- IBM 1440 - 1962
- IBM 1460 - 1963
- IBM 7010 Programming languages for the 1400 series included Autocoder (assembly language), COBOL, FORTRAN and Report Program Generator (RPG). The 1400 series was replaced by System/360 and low end machines like IBM System 3, System/32, System/34, System/36, System/38 and AS/400. The 1400's were officially withdrawn in the early 1970s. Category:IBM hardware

1960s

The 1960s in its most obvious sense refers to the decade between 1960 and 1969, but the expression has taken on a wider meaning over the past twenty years. The Sixties has come to refer to the complex of inter-related cultural and political events which occurred in approximately that period, in western countries, particularly Britain, France, the United States and West Germany. Social upheaval was not limited to just these nations, reaching large scale in nations such as Japan, Mexico and Canada as well. The term is used both nostalgically by those who participated in those events, and pejoratively by those who regard the time as a period whose harmful effects are still being felt today. The decade was also labelled the Swinging Sixties because of the libertine attitudes that emerged during the decade. Popular memory has conflated into the Sixties some events which did not actually occur during the period. For example, although some of the most dramatic events of the American civil rights movement occurred in the early 1960s, the movement had already began in earnest during the 1950s. On the other hand, the rise of feminism and gay rights began only in the very late 1960s and did not fully flower until the Seventies. However, the "Sixties" has become synonymous with all the new, exciting, radical, subversive and/or dangerous (according to one's viewpoint) events and trends of the period.

Events and trends

Many of the trends of the 1960s were due to the demographic changes brought about by the baby boom generation, the height of the Cold War, and the dissolution of European colonial empires. The rise in social revolution, civil rights movements, human rights movement, anti-War movements, and the Counterculture movement are only some of the characteristics that defined the 1960s. Many experts attribute the 1960s "counter-culture revolution" as being the result of the major social and political factors that rose in the 1950s like brinksmanship, continued fighting in the 3rd world, and a return to pre-WWII lifestyle. The new generation was determined to reject a pre-WWII conformist lifestyle with men in suits and women in the kitchen. While many believed it to be just a "Western" phenomenon, the '60s revolution spread far beyond the borders of America and Western Europe. In South America, revolutions were at a height, in the Eastern Bloc, movements were made inspired by the Hungarian Revolution to reject Soviet domination, and in the Middle East attempted to resist Soviet and American domination (see Non-Aligned Movement). Overall, the '60s affected almost the entire globe. It was during this time that protectionist, command, and mixed economies reached their peak...

Technology

Non-Aligned Movement Non-Aligned Movement]
- USSR puts first man (Yuri Gagarin) and first woman (Valentina Tereshkova) in outer space
- The United States puts man on Earth's Moon (see Apollo 11)
- Geosynchronous satellites revolutionize global communications
- Start of the development of algorithmic information theory
- The ARPAnet, precursor of the Internet, is founded in 1969 as a United States Department of Defense project. The numbered series of Request For Comments (RFC) documents begins in order to document the standards and practices of this network, and continues to this day
- Direct Use of the Sun's Energy by pioneer solar-energy scientist Farrington Daniels is published (1964)
- Compact audio cassette introduced; begins to displace reel-to-reel audio tape recording for home users

Science


- Discovery of plate tectonics revolutionizes understanding of continental drift
- Jacques Monod and Francois Jacob discover the lac operon
- Rise of the science of ecology in the awareness of the intelligentsia

War, peace and politics

intelligentsia"]] intelligentsia]
- Cultural Revolution in mainland China causes political and economic chaos.
- Nigerian Civil War begins.
- 6-Day War between Israelis and Arabs in 1967.
- Beginning of The Troubles in Northern Ireland
- Berlin Wall built in 1961.
- Bay of Pigs Invasion in 1961, the United States sponsored an attempt to overthrow Cuba's socialist government and Fidel Castro.
- Civil rights movement in the United States; end of official segregation and disenfranchisement of African-Americans; racial tensions continue with large race riots in Watts (Los Angeles) in 1966, Detroit in 1967, and Hough and Glenville in Cleveland.
- Sino-Indian War in late 1962. China attacks India and gains some land in Kashmir.
- Cuban Missile Crisis in 1962.
- Indo-Pakistani War of 1965 over Kashmir ends in a stalemate.
- The Vietnam War and protests, leading to Kent State University shootings in May, 1970.
- Suppression of uprising in Czechoslovakia.
- The Stonewall Riots in New York City give birth to the gay rights movement, June 1969.
- United Nations imposes sanctions against South Africa to protest the policy of Apartheid.
- Students protesting perceived problems with the status-quo are suppressed with violence by police and soldiers in USA, France, Mexico, Czechoslovakia. See New Left.
- The Quiet Revolution (Révolution tranquille) begins in Quebec - precipitous decline of the Roman Catholic church, liberalism, social-democratic programs, and the birth of modern Quebec nationalism.
- The rise of radical feminism.

Economics


- Many countries in The West experience high economic growth (4 to 8% per year)

Culture


- Rock and roll develops, diversifies, and becomes very hip. The Beatles eclipse Elvis Presley and become the most popular musical artists in the world. "Topical" artists like Bob Dylan and Joan Baez worked social commentary into their music.
- 2001: A Space Odyssey hits movie theaters
- The long running BBC family science fiction show Doctor Who begins in 1963
- Star Trek makes its debut in 1966
- James Bond movies begin. Dr. No is the first of the series in 1962, starring Sean Connery as Bond
- Hippies, drug culture & rock and roll converge at the Woodstock festival, 1969
- In the West, the growing popularity of religions other than Christianity (for example, as discussed in the writings of Alan Watts), and of atheism; Time Magazine asks: "Is God Dead?" See Fourth Great Awakening, Consciousness Revolution
- Memorable expositions, or "World's Fairs," are held in Seattle (1962), New York (1964/1965), Montreal (1967) and San Antonio (1968)
- Progressive rock emerges
- The fine arts begins to move away from exclusively consisting of painting, drawing, and sculpture and begins to incorporate elements from popular culture (Pop art) and begins to favour the ideas behind a work, rather than the work itself (Conceptual art)

Others

Conceptual art built in 1969]]
- Post-Colonialism; many new or previously colonized countries achieve independence in Africa, Asia
- U.S. president John F. Kennedy assassinated in 1963; his brother Robert F. Kennedy assassinated in 1968
- U.S. civil rights leader Martin Luther King Jr. assassinated on April 4, 1968
- Charles Manson gave up his ambitions of becoming a popular song writer to become a cult leader and mass murderer, 1969
- Nation of Islam leader Malcolm X assassinated on February 21, 1965
- U.S. president Lyndon B. Johnson's Great Society program
- In the United States, increase in crime; riots in Los Angeles in 1965 and Chicago, Illinois at the 1968 Democratic National Convention
- Rise of the baby boom generation to adulthood
- First widespread availability of practical birth control pill for women; See sexual revolution
- Sweden switches from driving on the left to the right, in order to harmonise with neighbouring countries. See Rules of the road

Big changes during the Sixties

In the United States

The movement for civil and political rights for African Americans (in the early '60s usually called Negroes and in the later '60s Blacks), initially a non-violent movement led by Martin Luther King, Jr. and other Gandhian figures but later producing radical offshoots such as the Black Power movement and competing with the Black Panther Party and the Black Muslims for primacy in the African-American community. The beginning of what was generally seen as a new political era with the election of President John F. Kennedy in 1960, and its ending in tragedy and disillusionment with Kennedy's assassination in 1963, the assassinations of King and Robert F. Kennedy in 1968, and the collapse of Lyndon Johnson's presidency. The rise of a mass movement in opposition to the Vietnam War, culminating in the massive Moratorium protests in 1969, and also the movement of resistance to conscription (“the Draft”) for the war. The antiwar movement was initially based on the older 1950s "Peace movement" controlled by the Communist Party USA, but by the mid '60s it outgrew this and became a broad-based mass movement centred on the universities and churches. Stimulated by this movement, but growing beyond it, the large numbers of student-age youth, beginning with the Free University of California, Berkeley]] in 1964, peaking in the riots at the 1968 Democratic National Convention in Chicago, Illinois and reaching a climax with the shootings at Kent State University in 1970. The rapid rise of a "New Left," employing the rhetoric of Marxism but having little organizational connection with older Marxist organizations such the Communist Party, and even less connection with the supposed focus of Marxist politics, the organized labor movement, and consisting of ephemeral campus-based Trotskyist, Maoist and anarchist groups, some of which by the end of the 1960s had turned to terrorism. terrorism The overlapping, but somewhat different, movement of youth cultural radicalism manifested by the hippies and the counter-culture, whose emblematic moments were the Summer of Love in San Francisco in 1967 and the Woodstock Festival in 1969. The rapid spread, associated with this movement, of the recreational use of cannabis and other drugs, particularly new synthetic psychedelic drugs such as LSD. The breakdown among young people of conventional sexual morality and the flourishing of the sexual revolution. Initially geared mostly to heterosexual male gratification, it soon gave rise to contrary trends, Women's Liberation and Gay Liberation. The rise of an alternative culture among affluent youth, creating a huge market for rock and blues music produced by drug-culture influenced bands such as The Beatles, Jefferson Airplane and The Doors, and also for radical music in the folk tradition pioneered by Bob Dylan.

In other Western countries

The peak of the student and New Left protests in 1968 coincided with political upheavals in a number of other countries. Although these events often sprang from completely different causes, they were influenced by reports and images of what was happening in the United States and France. Students in Mexico City, for example, protested against the corrupt regime of Gustavo Díaz Ordaz: in the resulting Tlatelolco massacre hundreds were killed. The influence of American culture and politics in Western Europe, Japan and Australia was already so great by the early 1960s that most of the trends described above soon spawned counterparts in most Western countries. University students rioted in London, Paris, Berlin and Rome, huge crowds protested against the Vietnam War in Australia and New Zealand (both of which had committed troops to the war), and politicians such as Harold Wilson and Pierre Trudeau modelled themselves on John F. Kennedy. An important difference between the United States and Western Europe, however, was the existence of a mass socialist and/or Communist movement in most European countries (particularly France and Italy), with which the student-based new left was able to forge a connection. The most spectacular manifestation of this was the May 1968 student revolt in Paris, which linked up with a general strike called by the Communist-controlled trade unions and for a few days seemed capable of overthrowing the government of Charles de Gaulle.

In non-Western countries

In Eastern Europe, students also drew inspiration from the protests in the west. In Poland and Yugoslavia they protested against restrictions on free speech by Communist regimes. In Czechoslovakia, 1968 was the year of Alexander Dubček’s Prague Spring, a source of inspiration to many Western leftists who admired Dubček's "socialism with a human face." The Warsaw Pact invasion of Czechoslovakia in August ended these hopes, and also fatally damaged the chances of the orthodox Communist Parties drawing many recruits from the student protest movement. In the People's Republic of China the mid 1960s were also a time of massive upheaval, and the Red Guard rampages of Mao Zedong's Cultural Revolution had some superficial resemblances to the student protests in the West. The Maoist groups that briefly flourished in the West in this period saw in Chinese Communism a more revolutionary, less bureaucratic model of socialism. Most of them were rapidly disillusioned when Mao welcomed Richard Nixon to China in 1972. People in China, however, saw the Nixon visit as a victory in that they believed the United States would concede that Mao Zedong thought was superior to capitalism (this was the Party stance on the visit in late 1971 and early 1972). The Cuban revolutionary Ernesto "Che" Guevara also became an iconic figure for the student left, although he was in fact an orthodox Communist.

People

World leaders

Ernesto "Che" Guevara]]
- Prime Minister Robert Menzies (Australia)
- Prime Minister Harold Holt (Australia)
- Prime Minister John McEwen (Australia)
- Prime Minister John Diefenbaker (Canada)
- Prime Minister Lester B. Pearson (Canada)
- Prime Minister Pierre Elliott Trudeau (Canada)
- Chairman Mao Zedong (People's Republic of China)
- President Chiang Kai-shek (Republic of China on Taiwan)
- President Gamal Abdel Nasser (Egypt)
- President Charles de Gaulle (France)
- Prime Minister Jawaharlal Nehru (India)
- Prime Minister Lal Bahadur Shastri (India)
- Prime Minister Indira Gandhi (India)
- Prime Minister David Ben-Gurion (Israel)
- Prime Minister Levi Eshkol (Israel)
- Emperor Hirohito (Japan)
- Pope John XXIII
- Pope Paul VI
- Prime Minister Basil Brooke (Northern Ireland)
- Prime Minister Terence O'Neill (Northern Ireland)
- Prime Minister James Chichester-Clark (Northern Ireland)
- Governor Luis A. Ferré (Commonwealth of Puerto Rico)
- Taoiseach Sean Lemass (Republic of Ireland)
- Taoiseach Jack Lynch (Republic of Ireland)
- Nikita Khrushchev (Soviet Union)
- Leonid Brezhnev (Soviet Union)
- Queen Elizabeth II (United Kingdom)
- Prime Minister Harold Macmillan (United Kingdom)
- Prime Minister Harold Wilson (United Kingdom)
- President Dwight D. Eisenhower (United States)
- President John F. Kennedy (United States)
- President Lyndon Johnson (United States)
- President Richard Nixon (United States)
- Chancellor Konrad Adenauer (West Germany)
- Chancellor Ludwig Erhard (West Germany)
- Chancellor Kurt Georg Kiesinger (West Germany)
- President for Life Josip Broz Tito (Yugoslavia)

Writers and intellectuals


- Isaac Asimov
- J. G. Ballard
- Truman Capote
- Andy Capp
- Rachel Carson
- Noam Chomsky
- Judith Christ
- Philip K. Dick
- Louise Fitzhugh
- Milton Friedman
- Allen Ginsberg
- Seamus Heaney
- Robert A. Heinlein
- Frank Herbert
- Ken Kesey
- Timothy Leary
- Norman Mailer
- Marshall McLuhan
- Jules Pfeiffer
- Carl Sagan
- Charles Schulz
- Dr. Seuss
- John Steinbeck
- Hunter S. Thompson
- Joseph Heller
- Gore Vidal
- Kurt Vonnegut
- Alan Watts
- Tom Wolfe

Sports figures


- Lance Alworth (American football player)
- Richie Benaud (Australian cricket captain)
- George Best (Northern Irish football player)
- Nino Benvenuti (Italian boxer)
- Jim Brown (American football player)
- Wilt Chamberlain (American basketball player)
- Bobby Charlton (English football player)
- Jim Clark (Scottish racing driver)
- Cassius Clay later known as Muhammad Ali (American boxer)
- Roberto Clemente (Puerto Rican baseball player)
- Eusebio (Portuguese football player)
- Peggy Fleming (American figure skater)
- Bob Gibson (American baseball player)
- Cookie Gilchrist (American football player)
- Bobby Hull (Canadian hockey player)
- Gordie Howe (Canadian hockey player)
- Franz Klammer (Austrian skier)
- David Kopay (American football player)
- Sandy Koufax (American baseball player)
- Denis Law (Scotland footballer)
- Vince Lombardi (American football coach)
- Willie Mays (American baseball player)
- Stan Mikita (Slovak-Canadian hockey player)
- Bobby Moore (English football player)
- Joe Namath (American football player)
- Jack Nicklaus (American golfer)
- Arnold Palmer (American golfer)
- Gary Player (South African golfer)
- Bobby Orr (Canadian ice hockey player)
- Pelé (Brazilian football player)
- Richard Petty (American NASCAR racing driver)
- Frank Robinson (American baseball player)
- Bill Shankly (Liverpool FC football manager)
- Gary Sobers (Barbados & West Indies cricket captain and all-rounder)
- Alfredo di Stefano (Argentinian/Spanish football player)
- Fred Trueman (Yorkshire & England cricketer)

Entertainers

cricket
- Bud Abbott
- Steve Allen
- Ursula Andress
- Julie Andrews
- Fred Astaire
- John Astin
- Frankie Avalon and Annette Funicello
- Joan Baez
- Lucille Ball
- Brigitte Bardot
- Billy Barty
- The Beach Boys
- The Beatles
- Tony Bennett
- Jack Benny
- Milton Berle
- Joey Bishop
- Ray Bolger
- Ernest Borgnine
- Charles Bronson
- Mel Brooks and Carl Reiner
- Johnny Brown
- Carol Burnett
- George Burns
- The Byrds
- Sid Caesar
- Godfrey Cambridge
- Diane Cannon
- Cantinflas
- Capucine
- Vicki Carr
- Diahann Carrol
- Johnny Carson
- Violet Carson
- Art Carney
- Jack Cassidy
- Ted Cassidy
- Carol Channing
- Roy Clark
- Imogene Coca
- Nat King Cole
- Sean Connery
- Tim Conway
- Bill Cosby
- Joan Crawford
- Bing Crosby
- Gary Crosby
- Phillip Crosby
- Tony Curtis
- Dalida
- Bette Davis
- Sammy Davis, Jr.
- Doris Day
- John Derrick
- Neil Diamond
- Angie Dickenson
- Walt Disney
- The Doors
- Donovan
- Mamie Van Doren
- Kirk Douglas
- Patty Duke
- Jimmy Durante
- Dick Van Dyke
- Bob Dylan
- Clint Eastwood
- Barbara Eden
- Linda Evans
- Robert Evans
- Henry Fonda
- Jane Fonda
- Peter Fonda
- Eileen Fulton
- Judy Garland
- James Garner
- Gerry & the Pacemakers
- Jack Gilford
- Jackie Gleason
- Cary Grant
- Kathryn Grant aka Kathryn Crosby
- Grateful Dead
- Dick Gregory
- Andy Griffith
- Merv Griffin
- Fred Gwynne
- Buddy Hackett
- Joey Heatherton
- Jimi Hendrix
- Audrey Hepburn
- Katharine Hepburn
- Charlton Heston
- Alfred Hitchcock
- Dustin Hoffman
- Bob Hope
- Dennis Hopper
- Ron Howard
- Rock Hudson
- The Jackson 5
- Chad and Jeremy
- Antonio Carlos Jobim
- Carolyn Jones
- Shirley Jones
- Tom Jones
- Janis Joplin
- Boris Karloff
- Danny Kaye
- Buster Keaton
- Gene Kelly
- Don Knotts
- Jimmy Komac
- Harvey Korman
- Nancy Kwan
- Bert Lahr
- Peter Lawford
- Norman Lear
- Bruce Lee
- Janet Leigh
- Jack Lemmon
- Jerry Lewis
- Art Linkletter
- Gina Lollobrigida
- Sophia Loren
- Peter Lorre
- Paul Lynde
- Shirley Maclaine
- Ann Margret
- Dean Martin
- Groucho Marx
- James Mason
- David McCallum
- Country Joe McDonald
- Steve McQueen
- Barry Melton
- The Monkees
- Mary Tyler Moore
- Rita Moreno
- Pat Morita
- Howard Morris
- Zero Mostel
- Paul Newman
- Jack Nicholson
- David Niven
- Roy Orbison
- Gregory Peck
- Peter & Gordon
- Oscar Peterson
- Patricia Phoenix
- Pink Floyd
- Sidney Poitier
- Vincent Price
- Richard Pryor
- Elvis Presley
- Otis Redding
- Robert Redford
- Steve Reeves
- Debbie Reynolds
- Don Rickles
- Chita Rivera
- The Rolling Stones
- Mickey Rooney
- Dan Rowan and Dick Martin
- Peter Sellers
- Rod Serling
- David Seville
- Dick Shawn
- Dinah Shore
- Simon & Garfunkel
- Frank Sinatra
- Frank Sinatra, Jr.
- Nancy Sinatra
- Red Skelton
- The Smothers Brothers
- Elke Sommer
- Sonny and Cher
- Jill St. John
- Connie Stevens
- Inger Stevens
- Stella Stevens
- James Stewart
- Ed Sullivan
- The Supremes
- Russ Tamblyn
- Jacques Tati
- Elizabeth Taylor
- Danny Thomas
- Marlo Thomas
- The Three Stooges
- Spencer Tracy
- Robert Wagner
- William Wagoner
- Burt Ward
- John Wayne
- Tuesday Weld
- Raquel Welch
- Orson Welles
- Adam West
- The Who
- Gene Wilder
- Andy Williams
- Flip Wilson
- Natalie Wood
- Stevie Wonder
- Ed Wynn
- Keenan Wynn
- Led Zeppelin
- Bradley Football
- Cass Elliot -- The Mamas & the Papas
- Carl Stuart Hamblen

See also


- List of rock and roll albums in the 1960s

Further Viewing

To see examples of the idealism of the Sixties, view the Woodstock Movie.

External links


- [http://www.public.iastate.edu/~rjackson/webbibl.html The 1960s: A Bibliography] Category:1960s ko:1960년대 ja:1960年代 simple:1960s

Unit record equipment

Before the advent of electronic computers, data processing was performed using electromechanical devices called unit record equipment, electric accounting machines (EAM) or tabulating machines. A data processing shop would have at least one of most of the machine types. Data processing consisted of feeding decks of punch cards through the various machines in a carefully choreographed progression. Electronic accounting machines were as ubiquitous in industry and government in the first half of the twentieth century as computers became in the second half. The largest supplier of unit record equipment was IBM. This article reflects IBM practice and terminology.

Data Storage

The basic unit of data was the 80-column punch card. Each column represented a single digit, letter or special character. Data values consisted of a field of adjacent columns. An employee number might occupy 5 columns; hourly pay rate, 3 columns; hours actually worked in a given week, 2 columns; department number 3 columns; project charge code 6 columns and so on. Data was entered on the cards by a worker sitting at a machine called a key punch. The key punch had a keyboard similar to a typewriter and hoppers for blank and punched cards. Later model key punches (e.g. the IBM 026) printed the value of each column punched at the top of the card. In some cases decks of punched cards were then sent to a second machine called a verifier, which looked a lot like a key punch. Its operator entered the exact same data as the keypuncher, but the verifier machine merely checked to see if the data was the same. Valid cards had a small notch punched on the right hand edge.

Sorting

A major activity in any unit record shop was sorting decks of punch card into the proper order as determined by information punched in the card. The same deck might be sorted differently depending on the processing step. Sorters, like the IBM 80, took an input deck and sorted it into one of 13 output bins depending on which hole was punched in a selected column. The 13th bin was for blanks and rejects. Data processing tasks typically ran on a daily batch processing cycle. All the data cards punched during the day were sorted and merged with a master deck, which was then tabulated.

Tabulating

IBM 80 Reports and summary data were generated by accounting or tabulating machines (e.g. the IBM 407). The sorted deck was fed through the tabulating machine and each card was printed on its own line. Selected fields from each card were added to the value of one of several counters. At some signal, say a card with a special punch indicating it was a master card, a summary line would be produced containing the summed values.

Automatic Card Punchers


- Gang Punch - these would produce a large number of identically punched card, say for inventory tickets.
- Reproducing Punch - these could reproduce a deck of card in its entirety or they might just reproduce selected fields. A payroll master deck might be reproduced at the end of a pay period with the hours worked and net pay fields blank and ready for the next pay period's data. Programmers used these to make backups.
- Summary Punch - these were attached to tabulating machines and could record summary line on punch cards for later use.
- Mark Sense reader - these would detect pencil marks on bubbles printed on the card and punch the corresponding data values into the card. Later document origination machines (e.g. the IBM 519) could perform all of the above operations.

Specialized machines


- Collators - these machines had two input hopper and four or more output hoppers. They could merge card decks based on the plug-board's program.
- Interpreter - these machines would print the values of columns along the top of the card.
- Burster - separated multi-part printed forms into separate stacks of printout.

Programming

Unit record equipment (except for sorters) were programmed using a plug-board control panel. The panels had a matrix of holes organized into groups. A supply of wires with metal ferrules at each end were available. Each end of the wire would snap into one of the holes on the control and protrude out the back. The tips of the ferrules would be pressed against a matrix of contact on the machine when the board was latched into place. The output from some card column positions might be fed into a tabulating machine's counter, for example. A shop would typically have separate plug-boards for each task a machine was used for.

Unit Record Equipment in the Computer Age

Early computer programming shops used punch cards for program entry and storage. A typical corporate or university computer lab would have a room full of key punch machines for programmer use. An old IBM 407 accounting machine might be set up to allow newly created or edited programs to be listed (printed out on fan-fold paper) for proof reading. An IBM 519 might be provided to reproduce program decks for backup. The 519 could also punch sequential numbers in columns 73-80 of Cobol or Fortran program decks. Those languages and others reserved those columns for this purpose. An IBM 80-series sorter would be used to put things back in order if a sequenced deck was dropped. (A quicker, but less effective, protection against dropped card decks was drawing a diagonal line across the top of the deck with a marking pen.) Many organizations loathe to alter systems that are working, so production unit record installations remained in operation long after computers offered faster and more cost effective solutions. Specialized uses of punch cards, including toll collection, microfilm aperture cards, and punch card voting, keep unit record equipment in use into the twenty-first century.

See also:


- IBM System 3 which introduced a 96-column card.
- List of IBM products
- List of UNIVAC products

External Links:


- [http://www.columbia.edu/acis/history/tabulator.html IBM Tabulators and Accounting Machines at Columbia University]
- [http://www.officemuseum.com/data_processing_machines.htm Early office museum] Category:IBM hardware Category:History of computing

Core memory

Magnetic core memory, or ferrite-core memory, is an early form of computer memory. It uses small magnetic ceramic rings, the cores, to store information via the polarity of the magnetic field they contain. Such memory is often just called core memory, or, informally, core.

History

The earliest work on core memory was carried out by the Shanghai-born American physicists, An Wang and Way-Dong Woo, who created the pulse transfer controlling device in 1949. The name referred to the way that the magnetic field of the cores could be used to control the switching of current in electro-mechanical systems. Wang and Woo were working at Harvard University's Computation Laboratory at the time, but unlike MIT, Harvard was not interested in promoting inventions created in their labs. Instead Wang was able to patent the system on his own while Woo took ill. Jay Forrester's group, working on the Whirlwind project at MIT, became aware of this work. This machine required a fast memory system for realtime flight simulator use. At first, Williams tubes (more accurately, Williams-Kilburn tubes) — a storage system based on cathode-ray-tubes — were used, but these devices were always temperamental and unreliable. Two key inventions led to the development of magnetic core memory, which enabled the development of computers as we know them. The first, An Wang's, was the write-after-read cycle, which solved the puzzle of how to use a storage medium in which the act of reading was also an act of erasure. The second, Jay Forrester's, was the coincident-current system, which enabled a small number of wires to control a large number of cores (see Description section below for details). Forrester's coincident-current system required one of the wires to be run at 45 degrees to the cores, which proved impossible to wire mechanically. Thus core arrays were manually assembled; the work was performed under microscopes and required fine motor control. Initially garment workers were used. By the late 1950s industrial plants had been set up in the far east to build core. Inside, hundreds of low-paid workers strung cores for cents a day. This lowered the cost of core to the point where it became largely universal as main memory by the early-1960s, replacing both the low-cost/low-performance drum memory as well as the high-cost/high-performance systems using vacuum tubes as memory. Although the manufacture of core memory was never automated, costs almost followed the not-yet-formulated Moore's Law; over the lifetime of the technology costs began at roughly a dollar a bit and eventually approached roughly $0.01 per bit. Core was in turn replaced by silicon memory chips (RAM) in the early 70s. Dr. Wang's patent was not granted until 1955, and by this time core was already in use. This started a long series of lawsuits, which eventually ended when IBM paid Wang several million dollars to buy the patent outright. Wang used the funds to greatly increase the size of Wang Laboratories which he co-founded with Dr. Ge-Yao Chu, a school mate from China. Core memory was part of a family of related technologies, now largely forgotten, which exploited magnetic properties of materials to perform switching and amplification. By the 1950's, vacuum-tube electronics was well-developed and very sophisticated, but tubes were fragile, and the use of heated filaments made them short-lived, high in power consumption, and unstable in their operating characteristics. Magnetic devices had many of the virtues of the transistor and solid-state devices that would replace them, and saw considerable use in military applications. A notable example was the portable (truck-based) MOBIDIC computer developed by Sylvania for the U. S. Army Signal Corps in the late fifties.

Description

MOBIDIC).
The light color vertical and horizontal wires are X and Y wires, the diagonal wires are Sense wires, the dark colored horizontal wires are Inhibit wires.]]

How core memory works

The most common form of core memory, X/Y line coincident-current – used for the main memory of a computer, consists of a large number of small ferrite (ferromagnetic ceramic) rings, cores, held together in a grid structure (each grid called a plane), with wires woven through the holes in the cores' middle. In early systems there were four wires, X, Y, Sense and Inhibit, but later cores combined the latter two wires into one Sense/Inhibit line. Each ring stores one bit (a 0 or 1), therefore many cores are needed to provide a reasonable amount of memory. Each plane stored one bit of an array of machine words, the full word was provided by a stack of planes. Only one word could be accessed in a single cycle. Core relies on the hysteresis of the magnetic material used to make the rings. Only a magnetic field over a certain intensity (generated by the wires through the core) can cause the core to change its magnetic polarity. To select a memory location, one of the X and one of the Y lines are driven with half the current required to cause this change. Only the combined magnetic field generated where the X and Y lines cross is sufficient to change the state, other cores will see only half the needed field, or none at all. By driving the current through the wires in a particular direction, the resulting induced field forces the selected core's magnetic field to point in one direction or the other (north or south). Other forms of core memory were used for other purposes. Register memory was often provided using word line core memory. This form of core memory typically wove three wires through each core on the plane, word read, word write, and bit sense/write, To read or clear words, the full current is applied to one or more word read lines; this clears the selected cores and any that flip induce voltage pulses in their bit sense/write lines. For read, normally only one word read line would be selected; but for clear, multiple word read lines could be selected while the bit sense/write lines ignored. To write words, the half current is applied to one or more word write lines, and half current is applied to each bit sense/write line for a bit to be set. For write, multiple word write lines could be selected. This offered a speed advantage over X/Y line coincident-current in that multiple words could be cleared or written with the same value in a single cycle. A typical machine's register set usually used only one small plane of this form of core memory. Another form of core memory called core rope memory provided read-only storage. In this case, the cores were simply used as transformers; no information was actually stored magnetically within the core.

Reading and writing

Reading from core memory is somewhat complex. Basically the read operation consists of doing a "flip to 0" operation to the bit in question, that is, driving the selected X and Y lines at half power in the direction that causes the core to flip to whatever polarity the machine considers to be zero. If the ring was already in the 0 state nothing will happen. However if the ring was in the 1 state it will flip to 0. If this flip occurs, a brief pulse of power will be induced into the Sense line, saying, in effect, that the memory location used to hold a 1. If the pulse is not seen that meant no flip occurred, so the ring must have already been in the 0 state. Note that every read forces the ring in question into the 0 state, so reading is destructive, which is one of the oddities of core memory. Writing is similar in concept, but always consists of a "flip to 1" operation, relying the memory already having been set to the 0 state in a previous read. If the ring in question is to hold a 1, then the operation proceeds normally and the ring flips to 1. However if the ring is to instead hold a zero, a small amount of current is sent into the Inhibit line, enough to drop the combined field from the X and Y lines below the amount needed to make the flip. This leaves the core in the 0 state. Note that the Sense and Inhibit wires are used one after the other, never at the same time. For this reason later core systems combined the two into a single wire, and used circuitry in the memory controller to switch the duty of the wire from Sense to Inhibit. Because core always requires a write after read, many computers included instructions that took advantage of this. These instructions would be used when the same location was going to be read, changed and then written, such as an increment operation. In this case the computer would ask the memory controller to do the read, but then signal it to pause before doing the write that would normally follow. When the instruction was complete the controller would be unpaused, and the write would occur with the new value. For certain types of operations, this effectively doubled the speed.

Physical characteristics

The speed of early core memories can be characterized in today's terms as being very roughly comparable to a clock speed of 1 MHz (0.001 GHz) (equivalent to early 1980s home computers, like the Apple II and Commodore 64). Early core memory systems had cycle times of about 6 µs, which had fallen to 1.2 µs by the early 1970s, and by the mid-70s it was down to 600 ns (0.6 µs). Everything possible was done in order to speed access, including the simultaneous use of multiple grids of core, each storing one bit of a data word. For instance a machine might use 32 grids of core with a single bit of the 32-bit word in each one, and the controller could access the entire 32-bit word in a single read/write cycle. Core memory is non-volatile storage – it can retain its contents indefinitely without power. It is also relatively unaffected by EMP and radiation. These were important advantages for some applications like military installations and vehicles like fighter aircraft, as well as spacecraft, and led to core being used for a number of years after availability of semiconductor MOS memory (see also MOSFET). A characteristic of core was that it is current-based, not voltage-based. The "half select current" was typically about 400 mA for later, smaller, faster cores. Earlier, larger cores required more current. Another characteristic of core is that the hysteresis loop was temperature sensitive, the proper half select current at one temperature is not the proper half select current at another temperature. So the memory controllers could include temperature sensors (typically a thermistor) to check the temperature and adjust the current levels to correct for temperature changes. An example of this is the core memory used by Digital Equipment Corporation for their PDP-1 computer; this strategy continued through all of the follow-on core memory systems built by DEC for their PDP line of air-cooled computers. Another method of handling the temperature sensitivity was to enclose the magnetic core "stack" in a temperature controlled oven. Examples of this are the heated air core memory of the IBM 1620 (which could take up to 30 minutes to reach operating temperature, about 106 °F, 41 °C) and the heated oil bath core memory of the IBM 709, IBM 7090, and IBM 7030.

Core trivia


- Although computer memory long ago moved to silicon chips, a file which is a dump of memory produced after a program error is still known as a core dump.

See also


- Delay line memory
- Core rope memory
- Twistor memory
- Bubble memory
- Thin film memory
- MRAM
- Ferroelectric RAM

External links


- [http://www.columbia.edu/acis/history/core.html Core Memory]
- [http://www.ed-thelen.org/comp-hist/navy-core-memory-desc.html Navy Manual]
- [http://www.psych.usyd.edu.au/pdp-11/core.html Core Memory on the PDP-11] Category:Computer memory Category:Non-volatile memory ja:磁気コアメモリ

Magnetic tape

Magnetic tape is a non-volatile storage medium consisting of a magnetic coating on a thin plastic strip. Nearly all recording tape is of this type, whether used for video with a videocassette recorder, audio storage (reel-to-reel tape, compact audio cassette, digital audio tape (DAT), digital linear tape (DLT) and other formats including 8-track cartridges) or general purpose digital data storage using a computer (specialized tape formats, as well as the above-mentioned compact audio cassette, used with home computers of the 1980s, and DAT, used for backup in workstation installations of the 1990s). Magneto-optical and optical tape storage products have been developed using many of the same concepts as magnetic storage, but have achieved little commercial success.

Magnetic tape audio storage

See:
- Sound Recording: Magnetic Recording.
- Tape recorder.
- Reel-to-reel audio tape recording.
- Compact audio cassette.
- 8-track cartridge.
- Audio tape length and thickness. See also audio storage for a comprehensive list of formats.

Magnetic tape video storage

see Videotape

Magnetic tape data storage

Image:Magnetic tape.jpg
half-inch (13 mm) reel tape
Magnetic tape was first invented by Fritz Pfleumer in 1928 in Germany, based on the invention of the magnetic wire by Valdemar Poulsen in 1898. It was not used to record data until 1951 on the Mauchly-Eckert UNIVAC I. The recording medium was a 1/2 inch (13 mm) wide thin band of nickel-plated bronze. Recording density was 128 characters per inch (198 micrometre/character) on eight tracks at a linear speed of 100 in/s (2.54 m/s), yielding a data rate of 12,800 characters per second. Making allowance for the empty space between tape blocks, the actual transfer rate was around 7,200 characters per second. IBM computers from the 1950s used oxide-coated tape similar to that used in audio recording, and IBM's technology soon became the de facto industry standard. Magnetic tape was half an inch wide and wound on removable reels 10.5 inches (267 mm) in diameter. Different lengths were available with 2400 feet and 4800 feet (732 and 1463 m) being common. Most modern magnetic tape systems use reels that are much smaller and are fixed inside a cartridge to protect the tape and facilitate handling. Modern cartridge formats include QIC, DAT, Exabyte, DLT and LTO. Early IBM tape drives were mechanically sophisticated floor-standing drives that used vacuum columns to buffer long u-shaped loops of tape. Between active control of powerful reel motors and vacuum control of these u-shaped tape loops, extremely rapid start and stop of the tape at the tape-to-head interface could be achieved. When active, the two tape reels thus spun in rapid, uneven, unsynchronized bursts resulting in visually-striking action. Stock shots of such vacuum-column tape drives in motion were widely used to represent "the computer" in movies and television. LINCtape (and its derivative, DECtape) were variations on this "round tape." They were essentially a personal storage medium. They featured a fixed formatting track which, unlike standard tape, made it feasible to read and rewrite blocks repeatedly in place. LINCtapes and DECtapes had similar capacity and data transfer rate to the diskettes that displaced them, but their "seek times" were on the order of thirty seconds to a minute. A tape drive (or "transport" or "deck") uses precisely-controlled motors to wind the tape from one reel to the other, passing a read/write head as it does. Early tape had seven parallel tracks of data along the length of the tape allowing six bit characters plus parity written across the tape. A typical recording density was 556 characters per inch. The tape had reflective marks near its end which signaled beginning of tape (BOT) and end of tape (EOT) to the hardware. Since then, a multitude of tape formats have been used, but common features emerge. In a typical format, data is written to tape in blocks with inter-block gaps between them, and each block is written in a single operation with the tape running continuously during the write. However, since the rate at which data is written or read to the tape drive is not deterministic, a tape drive usually has to cope with a difference between the rate at which data goes on and off the tape and the rate at which data is supplied or demanded by its host. Various methods have been used alone and in combination to cope with this difference. A large memory buffer can be used to queue the data. The tape drive can be stopped, backed up, and restarted. The host can assist this process by choosing appropriate block sizes to send to the tape drive. There is a complex tradeoff between block size, the size of the data buffer in the record/playback deck, the percentage of tape lost on inter-block gaps, and read/write throughput. Tape has quite a long data latency for random accesses since the deck must wind an average of 1/3 the tape length to move from one arbitrary data block to another. Most tape systems attempt to alleviate the intrinsic long latency using either indexing, whereby a separate lookup table is maintained which gives the physical tape location for a given data block number, or marking, whereby a tape mark that can be detected while winding the tape at high speed is written to the tape. Most tape drives now include some kind of data compression. There are several algorithms which provide similar results: LZ (Most), IDRC (Exabyte), ALDC (IBM, QIC) and DLZ1 (DLT). The actual compression algorithms used are not the most effective known today, and better results can usually be obtained by turning off the compression built into the device and using a software compression program instead. Tape remains a viable alternative to disk due to its higher bit density and lower cost per bit. Tape has historically offered enough advantage in these two areas above disk storage to make it a viable product. The recent vigorous innovation in disk storage density and price, coupled with less-vigorous innovation in tape storage, has reduced the viability of tape storage products.

References

Category:Audio storage Category:Computer storage tape media Category:Magnetic devices
- [http://www.guitarz-for-ever.com/the-basics-of-audio-recording.html The Basics of Audio Recording] ja:磁気テープ

Early IBM disk storage

Magnetic disk storage is a critical component of the computer revolution. IBM was a pioneer in this area. This article surveys the major IBM computer disk drives introduced in the 1950s, 1960s and early 1970s. The basic mechanical arrangement of hard disk drives hasn't changed since the IBM 1301. Disk drive performance characteristics are specified the same way today as they were in the 1950s. A modern (2004) PC hard drive is included for comparison. The reader may wish to calculate the ratio of cost-per-megabyte between the IBM 1301 and the 2004 PC hard drive. Few products in history have enjoyed such a meteoric decline in cost and size with such a stellar improvement in capacity.

IBM 350

The IBM 350 was part of the IBM RAMAC 305, the computer that introduced disk storage technology to the world on September 4, 1956. RAMAC stood for "Random Access Method of Accounting and Control." The 350 stored 5 million characters. It had fifty 24-inch diameter disks with 100 recording surfaces. Each surface had 100 tracks. The disks spun at 1200 RPM. Data transfer rate was 8,800 characters per second. Two independent access arms moved up and down to select a disk and in and out to select a recording track, all under servo control. A third arm was added as an option. Several improved models were added in the 1950s. The IBM RAMAC 305 system with 350 disk storage leased for $3,200 per month. The 350 was officially withdrawn in 1969. The 350's cabinet was 60 inches long, 68 inches high and 29 inches deep. IBM had a strict rule that all its products must pass through a standard 29.5 inch doorway. Since the 350's platters were mounted horizontally, this rule presumably dictated the maximum diameter of the disks.

IBM 353

The IBM 353 used on the IBM 7030, was similar to the IBM 1301, but much faster. It had a capacity of 2,097,152 (2^21) 72-bit words (64 data bits and 8 ECC bits) and transferred 125,000 words per second.

IBM 355

The IBM 355 was announced on September 14, 1956 as an addition to the popular IBM 650. It used the same mechanism as the IBM 350 and stored 6 million decimal digits. Data was transferred to and from the IBM 653 magnetic core memory, an IBM 650 option that stored just sixty 10-digit words, enough for a single sector of disk or tape data.

IBM 1405

The IBM 1405 Disk Storage Unit was announced by 1961 and was designed for use with the IBM 1401 series medium scale business computers. The 1405 stored 10 million characters on a single module. Each module had 25 large disks, yielding 50 recording surfaces. The disks spun at 1200 RPM. The Model 1 had one module, the Model 2 had two modules, stacked vertically. Each recording surface had 200 tracks and 5 sectors per track. Data was read or recorded at 22,500 characters per second. A single arm moved in and out and up and down. Access time ranged from 100 to 800 milliseconds (Model 2).

IBM 1301

The IBM 1301 Disk Storage Unit was announced on June 2, 1961. It was designed for use with the IBM 7000 series mainframe computers and the IBM 1410. The 1301 stored 28 million characters on a single module (25 million characters with the 1410). Each module had 20 large disks and 40 recording surfaces, with 250 tracks per surface. The 1301 Model 1 had one module, the Model 2 had two modules, stacked vertically. The disks spun at 1800 RPM. Data was transferred at 90,000 characters per second. A major advance over the IBM 350 and IBM 1405 was the use of a separate arm and head for each recording surface, with all the arms moving in and out together like a big comb. This eliminated the time needed for the arm to pull the head out of one disk and move up or down to a new disk. Seeking the desired track was also faster since, with the new design, the head would usually be somewhere in the middle of the disk, not starting on the outer edge. Maximum access time was reduced to 180 milliseconds. The 1301 also featured heads that were aerodynamically designed to fly over the surface of the disk on a thin layer of air. This allowed them to be much closer to the recording surface, which greatly improved performance. The 1301 was connected to the computer via the IBM 7631 File Control. Different models of the 7631 allowed the 1301 to be used with a 1410 or 7000 series computer or shared between a 7000 and a 1410 or between two 7000's. The IBM 1301 Model 1 leased for $2,100 per month or could be purchased for $115,500. Prices for the Model 2 were $3,500 per month or $185,000 to purchase. The IBM 7631 controller cost an additional $1,185 per month or $56,000 to purchase. All models were withdrawn in 1970.

IBM 1302

The IBM 1302 Disk Storage Unit was introduced in September 1963. Improved recording quadrupled its capacity over that of the 1301, to 117 million 6-bit characters per module. Average access time was 165 ms and data could be transferred at 180 K characters/second, more than double the speed of the 1301. A second arm accessed a separate group of 250 tracks. As with the 1301, there was a Model 2 with twice the capacity. The IBM 1302 Model 1 leased for $5,600 per month or could be purchased for $252,000. Prices for the Model 2 were $7,900 per month or $355,500 to purchase. The IBM 7631 controller cost an additional $1,185 per month or $56,000 to purchase. The 1302 was withdrawn in February 1965.

IBM 1311

1965 The IBM 1311 Disk Storage Drive was announced on October 11, 1962 and was designed for use with several medium-scale business and scientific computers. The 1311 was about the size and shape of a top-loading washing machine and stored 2 million characters on a removable IBM 1316 disk pack. Each disk pack was 4 inches high, weighed 10 pounds (4.5 kg) and contained six 14-inch diameter disks, yielding 10 recording surfaces (the outer surfaces were not used). The disks spun at 1500 RPM. Each recording surface had 100 tracks with 20 sectors per track. Each sector stored 100 characters. Five models of the 1311 were introduced during the 1960s. They were withdrawn during the early 1970s. Models of the 1311 disk drive: #Must be drive 1 on an IBM 1440, IBM 1460, or IBM 1240 system. Contains the controller and can control up to 4 – Model 2 drives. #Slave drive. Could have any special feature incorporated that the master drive (drive 1) had incorporated. #Must be drive 1 on an IBM 1620 or IBM 1710 system. Contains the controller and can control up to 3 – Model 2 drives. Did not support any special features. #Must be drive 1 on an IBM 1401 system. Contains the controller and can control up to 4 – Model 2 drives. #Must be drive 1 on an IBM 1410, IBM 7010, or IBM 7740 system. Contains the controller and can control up to 4 – Model 2 drives. Direct Seek comes standard on this model. The optional special features were:
- Direct Seek: Without this option every seek returned to track zero first.
- Scan Disk: Automatic rapid search for identifier or condition.
- Seek Overlap: Allowed a seek to overlap ONE read or write and any number of other seeks.
- Track Record: Increased the capacity of the disk by writing ONE large record per track instead of using sectors. Drive 1 (the master drive: models 1, 3, 4, and 5) was about a foot wider than the other drives (the slave drives: model 2), to contain extra power supplies and the control logic. The IBM 1316 Disk Packs were covered with a clear plastic shell and a bottom cover when not in use. A lifting handle in the top center of the cover was rotated to release the bottom cover. Then the top of the 1311 drive was opened and the plastic shell was lowered into the disk drive opening (assuming it was empty). The handle was turned again to lock the disks in place and release the plastic shell, which was then removed and the drive cover closed. The process was reversed to remove a disk pack.

IBM 2311

The IBM 2311 Direct Access Storage Facility was introduced in 1964 for use throughout the System/360 series. It was also available on the IBM 1130. The 2311 mechanism was largely identical to the 1311, but recording improvements allowed higher data density. The 2311 stored 7.25 million bytes on a single removable IBM 1316 disk pack (the same type used on the IBM 1311). Each recording surface had 200 tracks. Average seek time was 85 ms. Data transfer rate was 156 kB/s. Because the 2311 was to be used with a wide variety of computers within the 360 product line, its electrical interconnection was standardized. This created an opportunity for other manufacturers to sell plug compatible disk drives for use with IBM computers and an entire industry was born.

IBM 2314

The IBM 2314 Disk Storage Drive was introduced on April 22, 1965, one year after the System/360 introduction. It was used with the System/360 and the System/370 lines. The 2314 mechanism was similar to the 2311, but further recording improvements allowed higher data density. The 2314 stored 29.2 million characters on a single removable IBM 2316 disk pack. Each disk pack was contained eleven 14-inch diameter disks, yielding 20 recording surfaces. Each recording surface had 200 tracks. Access time was initially the same as the 2311, but later models were faster. Data transfer rate was doubled to 310 kB/s. The IBM 2316 disk pack was similar in design to the 1316, but higher and heavier.

IBM 2310

The IBM 2310 Removable Cartridge Drive was introduced with the IBM 1130 in 1965. It could store 512,000 words (1,024,000 bytes) on a IBM 2315 cartridge. A single disk spun in a plastic shell with openings for the read/write arm and head.

IBM 3330

The IBM 3330 Direct Access Storage Facility, code named Merlin, was introduced in June 1970 for use with the IBM System/370 and the IBM System 360/195. Its removable disk packs held 100 megabytes (the 1973 Model 11 featured IBM 3336 Disk Packs that held 200 megabytes). Access time was 30 millisecond and data transferred at 806 kB/s. A major advance introduced with the 3330 was the use of error correction, which made the drives more reliable and reduced costs because small imperfections in the disk surface could be tolerated. The circuitry could correct error bursts up to 11 bits long. The 3330 was withdrawn in 1983. The IBM 3330 DASD was the first disk drive to use voice coil motor technology to position the read/write heads over the tracks of data. Prior to the 3330 (e.g. 1301,1311, 2311, 2411), hydraulic units were used to position the heads.

IBM 3340

The IBM 3340 Direct Access Storage Facility, code named Winchester, was introduced in March 1973 for use with IBM System/370. It was named after the famous 30-30 Winchester rifle. Its removable disk packs were sealed and included the head and arm assembly. There was no cover to remove during the insertion process. Access time was 25 millisecond and data transferred at 885 kB/s. Three versions of the removable IBM 3348 Data Module were sold, one with 35 megabyte capacity, another with 70 megabytes, the third also had 70 megabytes, but with 500 kilobytes under separate fixed heads for faster access. The 3340 also used error correction. It was withdrawn in 1984.

The floppy disk

Another important IBM innovation was little noticed when it was introduced with the System/370 in 1971. IBM needed a way to load new microcode into the IBM System/370 Model 158 and developed the floppy disk for this purpose. Floppy disks were invented in 1952 by Yoshiro Nakamats, eighteen years before IBM "introduced" them. cf: http://www.japaninc.net/article.php?articleID=653 and Yoshiro Nakamatsu IBM's "first" floppies were 8 inches in diameter and held 80 K bytes of data. Floppies were not used for regular program or data storage on the 370, but they became key to the development of the personal computer in the late 1970s.

Disk storage in 2004

IBM sold its disk drive operation to Hitachi in 2002. For comparison purposes, the Hitachi Deskstar 7K250 PC hard drive stores 250,000,000,000 bytes (250 Gigabytes) on three 3.5-inch diameter platters spinning at 7200 RPM. It has a sustained average transfer rate of 61,400,000 bytes per second over a serial ATA bus. The average seek time is 8.5 milliseconds. It weighs 640 grams (1.4 lb). Like all 3.5 inch hard drives, it's about as long as the carrying handle on an IBM 1316 disk pack. You could buy one retail in July 2004 for about $200.

See also


- Kryder's law

External links


- [http://www.research.ibm.com/journal/rd/255/ibmrd2505ZC.pdf A Quarter Century of Disk File Innovation] – IBM Journal of Research and Development, 1981 (PDF)
- [http://www.tmth.edu.gr/el/expo/computers/00241.html IBM 1311 at the Thessaloniki Science Center & Technology Museum]
- [http://www.eetimes.com/news/98/1016news/disk.html EE Times: Disk drives take eventful spin] Category:Computer storage Category:Computing comparison Category:Early computers Disk Category:IBM storage devices IBM disks

IBM 1401

The IBM 1401 was a variable wordlength decimal computer that was announced by IBM on October 5, 1959 and marketed as an inexpensive "Business Computer". It was withdrawn on February 8, 1971. Although described as a (BCD) computer, each byte (or alphameric character) in the 1401 was represented by six bits, called A, B, 8, 4, 2 and 1. The A and B bits were called zone bits and the 8, 4, 2 and 1 bits were called numeral or BCD bits. Associated with each six-bit byte were two other bits, called C for odd parity check and M for wordmark, in the following format: C B A 8 4 2 1 M An IBM 1401 core memory address consisted of three six-bit bytes. The decimal address within a 1000-byte page was specified by the BCD bits of the address. Addresses that did not contain valid BCD codes in these bits caused a hard halt. Early machines used the A and B bits of the high-order byte to specify which of four pages was referred to, giving an addressability of 4,000 bytes in all. Several storage sizes were available up to this maximum. Later machines used the zone bits of the low-order byte to increase this maximum to 16,000 bytes, with an IBM 1406 memory expansion unit. The zone bits of the middle byte were used to specify index registers, one of many optional features. The 1401 was the first member of the IBM 1400 series. The IBM 1410 was a similar design, but with a larger address space. The last member was the IBM 1460, logically but not physically identical to a fully optioned 1401 with 16,000 bytes of memory. Instructions were of six lengths (1, 2, 4, 5, 7, 8). One-byte instructions consisted of only an opcode and were called chained instructions as they used the addresses left by the previous instruction when it completed. Two-byte instructions consisted of an opcode and a modifier byte. Four-byte instructions consisted of an opcode followed by an address, five byte instructions an opcode, address and modifier byte, seven byte instructions an opcode followed by two addresses, and eight byte instructions an opcode, two addresses and a modifier byte. Instructions were only valid if the wordmark was set on the low-order (opcode) byte and nowhere else in the instruction. Instruction fetching stopped and execution began when the another byte with the wordmark set was encountered (the valid opcode byte of the next instruction); there were two exceptions to this rule: #The dyadic SET WORDMARK instruction, which set two wordmarks, is seven bytes even without a following valid opcode. #The unconditional BRANCH INDICATOR instruction, is five bytes even without a following valid opcode. :Note: Other than these two exceptions, if no valid opcode was found by the 9th byte, the instruction was treated as an 8 byte instruction, but the computer continued scanning for a valid opcode (ignoring the bytes) until one was found before beginning execution or an error was detected (e.g., the end of memory). This was usually considered sloppy programming but not necessarily an error. When the LOAD button on the IBM 1402 reader/punch was pressed, a card was read into the card read buffer (core locations 1-80), a wordmark was set in location 1 (validating the first instruction on the card), and clearing the wordmarks in locations 2-80. Thus, the first instruction of any bootstrap program was a dyadic set wordmark, which validated two other instructions. In practice, the first few cards of a card-deck bootstrap program would consist entirely of dyadic set wordmark instructions, no-op instructions, a "read card", and an unconditional branch, which would set up a pattern of wordmarks in the card read buffer. The "read card" instruction did not change any wordmarks in the card read buffer. By use of no-op instructions of various lengths, the next few cards would conform to this pattern of wordmarks. The IBM 1401 was also commonly used as an off-line peripheral controller in many installations of both large "Scientific Computer"s and large "Business Computer"s. In these installations the big computer (e.g., an IBM 7090) did all of its input-output on magnetic tapes and the 1401 was used to format input data from other peripherials (e.g., punch card readers) on the tapes and transfer output data from the tapes to other peripherals (e.g., punch card punches or the IBM 1403 lineprinter). At peak, there were over 10,000 installed systems running in the mid-1960s. The IBM 1401 was withdrawn in February 1971. During its lifetime about 20,000 total systems were manufactured, making the IBM 1401 one of IBM's most successful products. Major software on the 1401 included a simple assembler called the Symbolic Programming System (SPS) and a more advanced form of assembler, Autocoder. The only high-level language in common use was the RPG (Report Program Generator) language, a declarative language primarily for specifying accounting reports still in use on IBM's midrange AS/400. Fortran was available for systems containing at least 8000 memory locations and the optional hardware unit for multiplication and division and is described in an appendix of John A. N. Lee's 1968 book The Anatomy of a Compiler; the Fortran compiler, to generate code for small memories, used a pioneering form of interpreted "p-code" although, of course, its programmers had no name for what it is that they did. Elements within IBM, notably John Haanstra, an executive in charge of 1401 deployment, supported its continuation in larger models for evolving needs but the 1964 decision at the top to focus resources on the System/360 ended these efforts rather suddenly. Nonetheless, to preserve customer investment in 1401 software, IBM pioneered a use of microcode in the form of ROM which caused 360 models to emulate 1401 instructions well into the modern era... in some cases, perhaps, until Y2K efforts caused the still-running 1401 code to be rewritten. Notable installations included a high end 1440 at the Chicago police department installed by reformist superintendent Orlando Wilson in the early 1960s. During the 1970s, many installations in India used the 1401 and some of today's Indian software entrepreneurs started on this machine. An extant 1401 is being restored to operation at this writing at the Computer History Museum in Mountain View, California, complete with the old "false floor" of the mainframe era, used to hide cabling. Announced as marginal, and for the simple accounting of midrange companies and as a sort of slave print server to the IBM 7090, the 1401 (like many other platforms before it and since) attracted its own hard core of devoted followers, who could see that although marketed as limited in function, the 1401 was in logical terms a real computer, whose secrets could be unlocked by people sufficiently patient to understand its arcane addressing scheme, and to devise ways around its limitations.

Character and Op codes

The table below is listed in Character Collating Sequence.

Hardware implementation

Most of the logic circuitry of the 1401 was a type of diode-transistor logic (DTL), that IBM referred to as CTDL. Other IBM circuit types used were referred to as: Alloy (some logic, but mostly various non-logic functions, named for the kind of transistors used), CTRL (a type of resistor-transistor logic (RTL)). These circuits were constructed of individual discrete components mounted on single sided paper-epoxy printed circuit boards either 2.5 by 4.5 inches (38 by 114 mm) with a 16 pin gold plated edge connector (single wide) or 5.375 by 4.5 inches (82 by 114 mm) with two 16 pin gold plated edge connectors (double wide), that IBM referred to as SMS cards (Standard Modular System). The amount of logic on one card was similar to that in one 7400 series SSI or simpler MSI package (e.g., 3 to 5 logic gates or a couple of flip-flops on a single wide card up to about 20 logic gates or 4 flip-flops on a double wide card). These boards were inserted in sockets on racks, that IBM referred to as gates.

External links


- [http://www.bitsavers.org/pdf/ibm/14xx/A24-1403-5_1401RefMan_Apr62.pdf IBM 1401 System Reference Manual]
- [http://www-1.ibm.com/ibm/history/exhibits/mainframe/mainframe_PP1401.html 1401 Data Processing System]
- [http://www.multicians.org/thvv/1401s.html 1401s I have Known] Category:IBM hardware Category:Early computers Category:Mainframe computers

IBM 1410

The IBM 1410 was a variable wordlength decimal computer that was announced by IBM on September 12 1960 and marketed as a midrange "Business Computer". It was withdrawn on March 30 1970. The 1410 was similar in design to the very popular IBM 1401, but it had one major difference. Addresses were five characters long and allowed a maximum memory of 80,000 characters, much larger than than the 16,000 characters permitted by the 1401's three character addresses.

External links


- [http://www-1.ibm.com/ibm/history/exhibits/mainframe/mainframe_PP1410.html IBM Archives - 1410]
- [http://www.bitsavers.org/1401/kossow-docs.html Al Kossow's IBM 1400 Series Documents] Category:IBM hardware Category:Mainframe computers

1960

1960 (MCMLX) was a leap year starting on Friday (link will take you to calendar).

Events

January-February


- January - State of emergency is lifted in Kenya - Mau Mau Rebellion is officially over
- January 1 - Independence of Cameroon
- January 9-11 - Aswan High Dam construction begins in Egypt
- January 14 - Reserve bank and Commonwealth Bank are created
- January 21 - Mine collapses at Coalbrook, South Africa - 437 dead
- January 22 - In France, president Charles de Gaulle fires Jacques Massun, commander-in-chief for the French troops in Algeria
- January 22-23 - Jacques Piccard and Donald Walsh descend into the Marianas Trench in the bathyscape Trieste, reaching the depth of 10.916 meters
- January 23 - Jacques Piccard and Don Walsh in the bathyscaphe USS Trieste break a depth record when they descend to the bottom of Challenger Deep 35,820 feet (10,750 meters) below sea level in the Pacific Ocean
- January 24 - A major insurrection in Algiers against French colonial policy
- January 25 - The National Association of Broadcasters reacts to the Payola scandal by threatening fines for any disc jockeys who accepted money for playing particular records
- February 1 - In Greensboro, N.C., four black students from North Carolina Agricultural and Technical College begin a sit-in at a segregated Woolworth's lunch counter. Although they are refused service, they are allowed to stay at the counter. The event triggers many similar nonviolent protests throughout the South, and six months later the original four protesters are served lunch at the same counter.
- February 5 - Particle accelerator of CERN inaugurated in Geneve, Switzerland
- February 8