IBM 7090 - AbsoluteAstronomy.com

The IBM 7090 was a second-generation transistorized

Transistor computer

A transistor computer is a computer which uses discrete transistors instead of vacuum tubes. The "first generation" of electronic computers used vacuum tubes, which generated large amounts of heat, were bulky, and were unreliable. A "second generation" of computers, through the late 1950s and...

version of the earlier IBM 709

IBM 709

The IBM 709 was an early computer system introduced by IBM in August, 1958. It was an improved version of the IBM 704 and the second member of the IBM 700/7000 series of scientific computers....

vacuum tube mainframe computer

Mainframe computer

Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...

s and was designed for "large-scale scientific and technological applications". The 7090 was the third member of the IBM 700/7000 series scientific computers. The first 7090 installation was in November 1959. In 1960, a typical system sold for $2,900,000 or could be rented for $63,500 a month.

The 7090 used a 36-bit word length

36-bit word length

Many early computers aimed at the scientific market had a 36-bit word length. This word length was just long enough to represent positive and negative integers to an accuracy of ten decimal digits . It also allowed the storage of six alphanumeric characters encoded in a six-bit character encoding...

, with an address-space of 32K (32,768) words. It operated with a basic memory cycle of 2.18 μs, using the IBM 7302

IBM 7302

The IBM 7302 Core Storage unit was designed in 1957-1958 for the IBM 7030 . The IBM 7030 could use from one to sixteen IBM 7302s ; either individually or in interleaved groups of two or four. The IBM 7090 also used one IBM 7302. The IBM 7094 used one IBM 7302A. The IBM 7094 II used one IBM 7302,...

Core Storage core memory technology from the IBM 7030

IBM 7030

The IBM 7030, also known as Stretch, was IBM's first transistorized supercomputer. The first one was delivered to Los Alamos National Laboratory in 1961....

(Stretch) project.

The 7090 was six times faster than the 709, and could be rented for half the price.

IBM 7094 and IBM 7040/7044

Although the 709 was a superior machine to its predecessor, the 704, it was being built and sold at the time that transistor circuitry was supplanting vacuum tube circuits. Hence, IBM redeployed its 709 engineering group to the design of a transistorized successor. That project became called the 709-T (for Transistorized), which because of the sound when spoken, quickly shifted to the nomenclature 7090 (i.e., seven - oh - ninety). Similarly, the related machines such as the 7070 and other 7000 series equipment were called by names of digit - digit - decade (e.g., seven - oh -seventy).

An upgraded version, the IBM 7094, was first installed in September 1962. It had seven index registers, instead of three on the earlier machines. The 7094 console had a distinctive box on top that displayed lights for the four new index registers. photos The 7094 introduced double-precision floating point and additional instructions, but was largely backward compatible

Backward compatibility

In the context of telecommunications and computing, a device or technology is said to be backward or downward compatible if it can work with input generated by an older device...

with the 7090. Minor changes in instruction formats, particularly the way the additional index registers were addressed, sometimes caused problems.

In 1963, IBM introduced lower cost machines with a similar architecture, but fewer instructions and simplified I/O, called the IBM 7040
IBM 7040
The IBM 7040 was a historic but short-lived model of transistor computer built in the 1960s.It was announced by IBM in December 1961, but did not ship until April, 1963. A later member of the IBM 700/7000 series of scientific computers, it was a scaled down version of the IBM 7090. It was not fully...

and 7044. In April 1964, the first 7094 II was installed, which had almost twice as much general speed as the 7090 due to a faster clock cycle, dual memory banks and improved overlap of instruction execution, an early antecedent of superscalar

Superscalar

A superscalar CPU architecture implements a form of parallelism called instruction level parallelism within a single processor. It therefore allows faster CPU throughput than would otherwise be possible at a given clock rate...

design.

Instruction and data formats

The basic instruction format was a 3-bit prefix, 15-bit decrement, 3-bit tag, and 15-bit address. The prefix field specified the class of instruction. The decrement field often contained an immediate operand to modify the results of the operation, or was used to further define the instruction type. The three bits of the tag specified three index register
Index register
An index registerCommonly known as a B-line in early British computers. in a computer's CPU is a processor register used for modifying operand addresses during the run of a program, typically for doing vector/array operations...

s (seven in the 7094), the contents of which were subtracted from the address to produce an effective address. The address field contained either an address or an immediate operand.

Fixed point numbers were stored in binary sign/magnitude format
Computer numbering formats
A computer number format is the internal representation of numeric values in digital computer and calculator hardware and software.-Bits:The concept of a bit can be understood as a value of either 1 or 0, on or off, yes or no, true or false, or encoded by a switch or toggle of some kind...

.
Single precision floating point
Floating point
In computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...

numbers had a magnitude sign, an 8-bit excess-128 exponent and a 27 bit magnitude
Double precision floating point numbers, introduced on the 7094, had a magnitude sign, an 8-bit excess-128 exponent, and a 54 bit magnitude. The double precision number was stored in memory in an even-odd pair of consecutive words; the sign and exponent in the 2nd word were ignored when the number was used as an operand.
Alphanumeric characters were 6-bit BCD, packed six to a word.

Octal

The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Numerals can be made from binary numerals by grouping consecutive binary digits into groups of three...

notation was used in documentation and programming.

Input/Output

The 7090 series featured a data channel architecture for input and output, a forerunner of modern direct memory access

Direct memory access

Direct memory access is a feature of modern computers that allows certain hardware subsystems within the computer to access system memory independently of the central processing unit ....

I/O. Up to 8 data channels could be attached, with up to 10 IBM 729

IBM 729

The IBM 729 Magnetic Tape Unit was IBM's iconic tape mass storage system from the late 1950s through the mid 1960s. Part of the IBM 7 track family of tape units, it was used on late 700, most 7000 and many 1400 series computers...

tape drives attached to each channel. The data channels had their own very limited set of operations called commands. These were used with tape (and later, disk) storage as well as card units and printers, and offered high performance for the time. Printing and punched card

Punched card

A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...

I/O, however, employed modified unit record equipment

Unit record equipment

Before the advent of electronic computers, data processing was performed using electromechanical devices called unit record equipment, electric accounting machines or tabulating machines. Unit record machines were as ubiquitous in industry and government in the first half of the twentieth century...

and was slow. It became common to use a less expensive IBM 1401

IBM 1401

The IBM 1401 was a variable wordlength decimal computer that was announced by IBM on October 5, 1959. The first member of the highly successful IBM 1400 series, it was aimed at replacing electromechanical unit record equipment for processing data stored on punched cards...

computer to read cards onto magnetic tape

Magnetic tape

Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...

for transfer to the 7090/94. Output would be spooled
Spooling
In computer science, spool refers to the process of placing data in a temporary working area for another program to process. The most common use is in writing files on a magnetic tape or disk and entering them in the work queue for another process. Spooling is useful because devices access data at...

onto tape and transferred to the 1401 for printing or card punching using its much faster peripherals, notably the IBM 1403

IBM 1403

The IBM 1403 line printer was introduced as part of the IBM 1401 computer in 1959 and had an especially long life in the IBM product line. The original model could print 600 lines of text per minute and could skip blank lines at up to 75 inches/second. The standard model had 120 print...

line printer. Later IBM introduced the 7094/7044 Direct Coupled System, using data channel to data channel communication, with the 7094 primarily performing computations and the 7044 performing I/O operations.

Software

The 7090 and 7094 machines were quite successful for their time, and had a wide
variety of software provided for them by IBM. In addition, there was a very active user community within the user organization, SHARE.

IBSYS

IBSYS

IBSYS was the tape based operating system that IBM supplied with its IBM 7090 and IBM 7094 computers. A similar operating system , also called IBSYS, was provided with IBM 7040 and IBM 7044 computers...

was a "heavy duty" production operating system with numerous subsystem and language support options, among them FORTRAN

Fortran

Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...

, COBOL

COBOL

COBOL is one of the oldest programming languages. Its name is an acronym for COmmon Business-Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments....

, SORT/MERGE, the MAP assembler, and others.

FMS, the Fortran Monitor System, was a more lightweight but still very effective system optimized for batch FORTRAN and assembler programming. The assembler provided, FAP, (FORTRAN Assembly Program), was somewhat less complete than MAP, but provided excellent capabilities for the era. FMS also incorporated a considerably enhanced derivative of the FORTRAN compiler originally written for the 704 by Backus and his team.

Notable applications

The Compatible Time-Sharing System (CTSS), one of the first time-sharing
Time-sharing
Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.By allowing a large...

operating systems, was developed at MIT's Project MAC using a 7094 with an extra bank of memory, among other modifications.

NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

used 7090s, and, later, 7094s to control the Mercury
Project Mercury
In January 1960 NASA awarded Western Electric Company a contract for the Mercury tracking network. The value of the contract was over $33 million. Also in January, McDonnell delivered the first production-type Mercury spacecraft, less than a year after award of the formal contract. On February 12,...

and Gemini
Project Gemini
Project Gemini was the second human spaceflight program of NASA, the civilian space agency of the United States government. Project Gemini was conducted between projects Mercury and Apollo, with ten manned flights occurring in 1965 and 1966....

space flights. The IBM 7094 was used during the Apollo missions including Apollo 11 the moon landing. Goddard Space Flight center operated 3 7094s. During the early Apollo Program
Project Apollo
The Apollo program was the spaceflight effort carried out by the United States' National Aeronautics and Space Administration , that landed the first humans on Earth's Moon. Conceived during the Presidency of Dwight D. Eisenhower, Apollo began in earnest after President John F...

, a 7094 was kept operational to run flight planning software that had not yet been ported to mission control's newer System/360
System/360
The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...

computers.

Caltech/NASA Jet Propulsion Laboratory
Jet Propulsion Laboratory
Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...

had three 7094s in the Space Flight Operations Facility (SFOF, building 230), fed via tape using several 1401s, and two 7094/7044 direct-couple systems (in buildings 125 and 156).

The US Air Force retired its last 7090s in service from the Ballistic Missile Early Warning System
Ballistic Missile Early Warning System
The United States Air Force Ballistic Missile Early Warning System was the first operational ballistic missile detection radar. The original system was built in 1959 and could provide long-range warning of a ballistic missile attack over the polar region of the Northern Hemisphere. They also...

("BMEWS") in the 1980s after almost 30 years of use.

The US Navy continued to use a 7094 at Pacific Missile Test Center
Pacific Missile Test Center
Pacific Missile Test Center is the former name of the current Naval Air Warfare Center, Weapons Division. The name of the center was the Naval Air Missile Test Center prior to PMTC. It is located at Naval Base Ventura County/Naval Air Station Point Mugu in Ventura County, California...

, Point Mugu, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

through much of the 1980s, although a "retirement" ceremony was held in July 1982. Not all of the applications had been ported to its successor, a dual-processor CDC Cyber
CDC Cyber
The CDC Cyber range of mainframe-class supercomputers were the primary products of Control Data Corporation during the 1970s and 1980s. In their day, they were the computer architecture of choice for scientific and mathematically intensive computing...

175.

A pair of 7090s in Briarcliff Manor, NY, were the basis for the original version of the SABRE
Sabre (computer system)
Sabre Global Distribution System , owned by Sabre Holdings, is used by more than 55,000 travel agencies around the world with more than 400 airlines, 88,000 hotels, 24 car rental brands, and 13 cruise lines...

airlines reservation system introduced by American Airlines in 1962.

In 1961 Alexander Hurwitz used a 7090 to discover two Mersenne primes, with 1281 and 1332 digits - the largest prime numbers known at the time.

In 1961, the 7094 became the first computer to sing, singing the song Daisy Bell
Daisy Bell
"Daisy Bell" is a popular song with the well-known chorus "Daisy, Daisy/Give me your answer do/I'm half crazy/all for the love of you" as well as the line "...a bicycle built for two".-History:"Daisy Bell" was composed by Harry Dacre in 1892...

. Vocals were programmed by John Kelly
John Larry Kelly, Jr
John Larry Kelly, Jr. , was a scientist who worked at Bell Labs. He is best known for formulating the Kelly criterion, an algorithm for maximally investing money....

and Carol Lockbaum and the accompaniment was programmed by Max Mathews
Max Mathews
Max Vernon Mathews was a pioneer in the world of computer music.-Biography:...

. This performance was the inspiration for a similar scene in 2001: A Space Odyssey
2001: A Space Odyssey (film)
2001: A Space Odyssey is a 1968 epic science fiction film produced and directed by Stanley Kubrick, and co-written by Kubrick and Arthur C. Clarke, partially inspired by Clarke's short story The Sentinel...

.

A 7090/1401 installation is featured in the motion picture Dr. Strangelove, with the 1403 printer
IBM 1403
The IBM 1403 line printer was introduced as part of the IBM 1401 computer in 1959 and had an especially long life in the IBM product line. The original model could print 600 lines of text per minute and could skip blank lines at up to 75 inches/second. The standard model had 120 print...

playing a pivotal role in the plot (it is the hiding place for a transistor radio; which, when found and turned on by one of the three characters played by Peter Sellers
Peter Sellers
Richard Henry Sellers, CBE , known as Peter Sellers, was a British comedian and actor. Perhaps best known as Chief Inspector Clouseau in The Pink Panther film series, he is also notable for playing three different characters in Dr...

in the film, reveals that the nuclear attack ordered by the deranged Air Force base commander is phony, and must be stopped at all costs).

The composer Iannis Xenakis
Iannis Xenakis
Iannis Xenakis was a Romanian-born Greek ethnic, naturalized French composer, music theorist, and architect-engineer. He is commonly recognized as one of the most important post-war avant-garde composers...

wrote his piece "Atrées" using an IBM 7090 at Place Vendôme
Place Vendôme
Place Vendôme is a square in the 1st arrondissement of Paris, France, located to the north of the Tuileries Gardens and east of the Église de la Madeleine. It is the starting point of the Rue de la Paix. Its regular architecture by Jules Hardouin-Mansart and pedimented screens canted across the...

, Paris.

Three 7090 systems were imported into and installed in Japan in 1963, one each at Mitsubishi Nuclear Power Co. (whose DP division later merged with Mitsubishi Research Institute, Inc.), IBM Japan's data center
Data center
A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems...

in Tokyo
Tokyo
, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...

, and Toshiba
Toshiba
is a multinational electronics and electrical equipment corporation headquartered in Tokyo, Japan. It is a diversified manufacturer and marketer of electrical products, spanning information & communications equipment and systems, Internet-based solutions and services, electronic components and...

in Kawasaki
Kawasaki, Kanagawa
is a city located in Kanagawa Prefecture, Japan, between Tokyo and Yokohama. It is the 9th most populated city in Japan and one of the main cities forming the Greater Tokyo Area and Keihin Industrial Area....

. They were mainly used for scientific computing.

External links

IBM Archives - 7090
IBM 7090 Data Processing System from BRL61 Report
IBM 7090/94 Architecture page
IBM 7090 Music From Mathematics recorded in 1960 by Bell Labs, using the "Digital to Sound Transducer" to realize several traditional and original compositions; this album contains the original Daisy (Bicycle Built for Two).
IBM 7094 singing Daisy (mp3)
Bob Supnik's SimH project – Includes a simulator for the 7090/7094 in a user-modifiable package
Dave Pitts' IBM 7090 support – Includes a simulator, cross assembler and linker