UNIVAC Sperry Rand label
Eckert and Mauchly built the ENIAC (Electronic Numerical Integrator and Computer) at the University of Pennsylvania's Moore School of Electrical Engineering between 1943 and 1946. A 1946 patent rights dispute with the university led Eckert and Mauchly to depart the Moore School to form the Electronic Control Company, later renamed Eckert-Mauchly Computer Corporation (EMCC), based in Philadelphia, Pennsylvania. That company first built a computer called BINAC (BINary Automatic Computer) for Northrop Aviation (which was little used, or perhaps not at all). Afterwards began the development of UNIVAC. UNIVAC was first intended for the Bureau of the Census, which paid for much of the development, and then was put in production.
With the death of EMCC's chairman and chief financial backer Harry L. Straus in a plane crash on October 25, 1949, EMCC was sold to typewriter maker Remington Rand on February 15, 1950. Eckert and Mauchly now reported to Leslie Groves, the retired army general who had managed the Manhattan Project. Remington Rand had its own calculating machine lab in Norwalk, Connecticut, and later bought Engineering Research Associates (ERA) in St. Paul, Minnesota. In 1953 or 1954 Remington Rand merged their Norwalk tabulating machine division, the ERA "scientific" computer division, and the UNIVAC "business" computer division into a single division under the UNIVAC name. This severely annoyed those who had been with ERA and with the Norwalk laboratory.
The most famous UNIVAC product was the UNIVAC I mainframe computer of 1951, which became known for predicting the outcome of the U.S. presidential election the following year. This incident is particularly infamous because the computer predicted an Eisenhower landslide when traditional pollsters all called it for Adlai Stevenson.[1] The numbers were so skewed that CBS's news boss in New York, Mickelson, decided the computer was in error and refused to allow the prediction to be read. Instead they showed some staged theatrics that suggested the computer was not responsive, and announced it was predicting 8-7 odds for an Eisenhower win (the actual prediction was 100-1). When the predictions proved true and Eisenhower won a landslide within 1% of the initial prediction, Charles Collingwood, the on-air announcer, embarrassingly announced that they had covered up the earlier prediction.
Eckert and Mauchly built the ENIAC (Electronic Numerical Integrator and Computer) at the University of Pennsylvania's Moore School of Electrical Engineering between 1943 and 1946. A 1946 patent rights dispute with the university led Eckert and Mauchly to depart the Moore School to form the Electronic Control Company, later renamed Eckert-Mauchly Computer Corporation (EMCC), based in Philadelphia, Pennsylvania. That company first built a computer called BINAC (BINary Automatic Computer) for Northrop Aviation (which was little used, or perhaps not at all). Afterwards began the development of UNIVAC. UNIVAC was first intended for the Bureau of the Census, which paid for much of the development, and then was put in production.
With the death of EMCC's chairman and chief financial backer Harry L. Straus in a plane crash on October 25, 1949, EMCC was sold to typewriter maker Remington Rand on February 15, 1950. Eckert and Mauchly now reported to Leslie Groves, the retired army general who had managed the Manhattan Project. Remington Rand had its own calculating machine lab in Norwalk, Connecticut, and later bought Engineering Research Associates (ERA) in St. Paul, Minnesota. In 1953 or 1954 Remington Rand merged their Norwalk tabulating machine division, the ERA "scientific" computer division, and the UNIVAC "business" computer division into a single division under the UNIVAC name. This severely annoyed those who had been with ERA and with the Norwalk laboratory.
The most famous UNIVAC product was the UNIVAC I mainframe computer of 1951, which became known for predicting the outcome of the U.S. presidential election the following year. This incident is particularly infamous because the computer predicted an Eisenhower landslide when traditional pollsters all called it for Adlai Stevenson.[1] The numbers were so skewed that CBS's news boss in New York, Mickelson, decided the computer was in error and refused to allow the prediction to be read. Instead they showed some staged theatrics that suggested the computer was not responsive, and announced it was predicting 8-7 odds for an Eisenhower win (the actual prediction was 100-1). When the predictions proved true and Eisenhower won a landslide within 1% of the initial prediction, Charles Collingwood, the on-air announcer, embarrassingly announced that they had covered up the earlier prediction.
In 1955 Remington Rand merged with Sperry Corporation to become Sperry Rand. The UNIVAC division of Remington Rand was renamed the Univac division of Sperry Rand. General Douglas MacArthur was chosen to head the company. In the 1960s, UNIVAC was one of the eight major American computer companies in an industry then referred to as "IBM and the seven dwarfs" — a play on Snow White and the seven dwarfs, with IBM, by far the largest, being cast as Snow White and the other seven as being dwarfs: Burroughs, Univac, NCR, CDC, GE, RCA and Honeywell.[3] In the 1970s, after GE sold its computer business to Honeywell and RCA sold its to Univac, the analogy to the seven dwarfs became less apt and the remaining small firms became known as the "BUNCH" (Burroughs, Univac, NCR, Control Data, and Honeywell).
Around 1975, to assist "corporate identity" the name was changed to Sperry Univac, along with Sperry Remington, Sperry New Holland, etc. In 1978 Sperry Rand, an old fashioned conglomerate of disharmonious divisions (computers, typewriters, office furniture, hay balers, manure spreaders, gyroscopes, avionics, radar, electric razors), decided to concentrate on its computing interests and unrelated divisions were sold. The company dropped the Rand from its title and reverted back to Sperry Corporation. In 1986, Sperry Corporation merged with Burroughs Corporation to become Unisys.
Since the 1986 marriage of Burroughs and Sperry, Unisys has metamorphosed from a computer manufacturer to a computer services and outsourcing firm, competing in the same marketplace as IBM, Electronic Data Systems (EDS), and Computer Sciences Corporation. Unisys continues to design and manufacture enterprise class computers with the ClearPath and ES7000 server lines.
Models
In the course of its history, UNIVAC produced a number of separate model ranges.
The original model range was the UNIVAC I (UNIVersal Automatic Computer I), the first commercial computer made in the United States. The main memory consisted of tanks of liquid mercury implementing delay line memory, arranged in 1000 words of 12 alphanumeric characters each. The first machine was delivered on 31 March 1951. Successor machines included:
The UNIVAC II was an improvement to the UNIVAC I that UNIVAC first delivered in 1958. The improvements included magnetic (non-mercury) core memory of 2000 to 10000 words, UNISERVO II tape drives which could use either the old UNIVAC I metal tapes or the new PET film tapes, and some circuits that were transistorized (although it was still a vacuum tube computer). It was fully compatible with existing UNIVAC I programs for both code and data. The UNIVAC II also added some instructions to the UNIVAC I's instruction set.
Sperry Rand began shipment of UNIVAC III in 1962, and produced 96 UNIVAC III systems. Unlike the UNIVAC I and UNIVAC II, however, it was a binary machine as well as maintaining support for all UNIVAC I and UNIVAC II decimal and alphanumeric data formats for backward compatibility. This was the last of the original UNIVAC machines.
The UNIVAC Solid State was a 2-address, bi-quinary coded decimal computer, with memory on a rotating drum with 5000 signed 10 digit words. For efficiency, programmers had to take into account drum latency, the time required for a specific data item, once written, to rotate to where it could be read. It was one of the first computers to use some solid-state components. It came in two versions: the Solid State 80 (IBM-Hollerith 80 column cards) and the Solid State 90 (Remington-Rand 90 column cards). This machine was designated the Solid State 80-90 and sold mostly in Europe. UNIVAC SS80/90s were installed at DC Transit, SBA, CWA, in Washington DC during the early sixties. It was a follow on to a computer built for the USAF and delivered to Lawrence G. Hanscom Field, near Cambridge, MA in 1957. This computer used magnetic amplifiers, not transistors. The decision to use magnetic amplifiers was made because the point-contact germanium transistors then available had highly variable characteristics and were not sufficiently reliable. The magnetic amplifiers were based on tiny (about 1/8" ID) toroidal stainless steel spools wound with two or so layers of 1/32" wide 4-79 moly-permalloy magnetic material to form magnetic cores. These cores had two windings of #60 copper wire surrounding the 4-79 molypermalloy. The magnetic amplifiers required clock pulses of heavy current that could not be produced by the transistors of the day. A transmitting vacuum-tube, of the type used in amateur radio final amplifiers, produced a powerful high-voltage signal which was stepped down to a 36-volt, high-current clock by oil-filled transformers that were distributed about the machine. Thus the SS 80/90, for the heart of its operation, depended on the very technology it claimed to replace, a marketing tactic. The clock tube was enclosed in a shielding box that constrained both radio emissions and viewing by eyes of other than Univac's field engineers. The SS80/90 was aimed at the general purpose business market.
Early UNIVAC 1100 series models were vacuum tube computers.
The original model range was the UNIVAC I (UNIVersal Automatic Computer I), the first commercial computer made in the United States. The main memory consisted of tanks of liquid mercury implementing delay line memory, arranged in 1000 words of 12 alphanumeric characters each. The first machine was delivered on 31 March 1951. Successor machines included:
The UNIVAC II was an improvement to the UNIVAC I that UNIVAC first delivered in 1958. The improvements included magnetic (non-mercury) core memory of 2000 to 10000 words, UNISERVO II tape drives which could use either the old UNIVAC I metal tapes or the new PET film tapes, and some circuits that were transistorized (although it was still a vacuum tube computer). It was fully compatible with existing UNIVAC I programs for both code and data. The UNIVAC II also added some instructions to the UNIVAC I's instruction set.
Sperry Rand began shipment of UNIVAC III in 1962, and produced 96 UNIVAC III systems. Unlike the UNIVAC I and UNIVAC II, however, it was a binary machine as well as maintaining support for all UNIVAC I and UNIVAC II decimal and alphanumeric data formats for backward compatibility. This was the last of the original UNIVAC machines.
The UNIVAC Solid State was a 2-address, bi-quinary coded decimal computer, with memory on a rotating drum with 5000 signed 10 digit words. For efficiency, programmers had to take into account drum latency, the time required for a specific data item, once written, to rotate to where it could be read. It was one of the first computers to use some solid-state components. It came in two versions: the Solid State 80 (IBM-Hollerith 80 column cards) and the Solid State 90 (Remington-Rand 90 column cards). This machine was designated the Solid State 80-90 and sold mostly in Europe. UNIVAC SS80/90s were installed at DC Transit, SBA, CWA, in Washington DC during the early sixties. It was a follow on to a computer built for the USAF and delivered to Lawrence G. Hanscom Field, near Cambridge, MA in 1957. This computer used magnetic amplifiers, not transistors. The decision to use magnetic amplifiers was made because the point-contact germanium transistors then available had highly variable characteristics and were not sufficiently reliable. The magnetic amplifiers were based on tiny (about 1/8" ID) toroidal stainless steel spools wound with two or so layers of 1/32" wide 4-79 moly-permalloy magnetic material to form magnetic cores. These cores had two windings of #60 copper wire surrounding the 4-79 molypermalloy. The magnetic amplifiers required clock pulses of heavy current that could not be produced by the transistors of the day. A transmitting vacuum-tube, of the type used in amateur radio final amplifiers, produced a powerful high-voltage signal which was stepped down to a 36-volt, high-current clock by oil-filled transformers that were distributed about the machine. Thus the SS 80/90, for the heart of its operation, depended on the very technology it claimed to replace, a marketing tactic. The clock tube was enclosed in a shielding box that constrained both radio emissions and viewing by eyes of other than Univac's field engineers. The SS80/90 was aimed at the general purpose business market.
Early UNIVAC 1100 series models were vacuum tube computers.
The UNIVAC 1100/2200 series is a series of compatible 36-bit transistorized computer systems initially made by Sperry Rand. The series continues to be supported today by Unisys Corporation as the ClearPath Plus Dorado Series.[4]
1.Remington Rand 409 was a control panel programmed punched card calculator, designed in 1949.
2.The UNIVAC 418 (aka 1219) was an 18-bit word core memory machine. Over the three different models, more than 392 systems were manufactured.
The UNIVAC 490 was a 30-bit word core memory machine with 16K or 32K words; 4.8 microsecond cycle time.
The UNIVAC 490 was a 30-bit word core memory machine with 16K or 32K words; 4.8 microsecond cycle time.
3.The UNIVAC 492 is similar to the UNIVAC 490, but with extended memory to 64K 30-bit words.
4.The UNIVAC 494 was a 30-bit word machine and successor to the UNIVAC 490/492 with faster CPU and 131K (later 262K) core memory. Up to 24 I/O channels were available and the system was usually shipped with UNIVAC FH880 or UNIVAC FH432 or FH1782 magnetic drum storage. Basic operating system was OMEGA (successor to REX for the 490) although custom operating systems were also used (e.g. CONTORTS for airline reservations).
5.The UNIVAC 1004 was a plug-board programmed punched card data processing system, introduced in 1962, by UNIVAC. Total memory was 961 characters (6 bits) of core memory. Peripherals were a card reader (400 cards/minute), a card punch (200 cards/minute) using proprietary 90-column, round-hole cards or IBM-compatible, 80-column cards, a drum printer (400 lines/minute) and a Uniservo tape drive. The 1004 was also supported as a remote card reader & printer via synchronous communication services. A U.S. Navy (Weapons Station, Concord) 1004 was dedicated to printing from tape as a means of offloading the task from their Solid State 80 mainframe, which produced the tapes. A plug-board program called Emulator was widely installed to convert 1004s to stored-program operation, reading in instructions from program decks of cards which determined the processing of the following data decks. Once installed, Emulator was rarely removed as it could run the machine as desired and, as almost every machine function was used, it was physically heavy from the sheer mass of installed jumpers filling nearly the entire board. Emulator was not a Univac product, rather it was built by each customer, a tedious task. Its heavy use of the 1004's program-branching reed relays, called selectors, caused increased failures, later solved by the use of electronic selectors in the follow-on 1005.
6.The UNIVAC 1005, an enhanced version of the UNIVAC 1004, was introduced in February 1966. The main improvement over the 1004 was conversion from the plug-board program to an internal stored program. The machine saw extensive use by the US Army, including the first use of an electronic computer on the battlefield. Additional peripherals were also available including a paper tape reader and a three pocket stacker selectable card read/punch. The machine had a two-stage assembler (SAAL - Single Address Assembly Language) which was its primary assembler; it also had a three stage card based compiler for a programming language called SARGE. 1005s were used as some nodes on Autodin.
7.The UNIVAC 1050 was an internally programmed computer with up to 32K of 6-bit character memory, which was introduced in 1963. It was a 1-address machine with 30-bit instructions, had a 4K operating system and was programmed in the PAL assembly language. The 1050 was used extensively by the U.S. Air Force supply system for inventory control.
8.The UNIVAC 9000 series (9200, 9300, 9400, 9700) was introduced in the mid-1960s to compete with the low end of the IBM 360 series. The 9000 series implemented the IBM 360 instruction set. The 9200 and 9300 (which differed only in CPU speed) implemented the same restricted 360 subset as the IBM 360/20, while the UNIVAC 9400 implemented the full 360 instruction set. The 9400 was roughly equivalent to the IBM 360/30. The 9000 series used plated wire memory, which functioned somewhat like core memory but used a non-destructive read. Since the 9000 series was intended as direct competitors to IBM, they used 80-column cards and EBCDIC character encoding.
9.The UNIVAC 90/60 Series (90/60, 90/70, 90/80): Later, more advanced machines such as the Univac 90/60 provided systems which featured virtual memory and thus were similar, or equivalent, to later IBM 370 mainframes. This didn't violate IBM copyrights. Sperry got the rights to "clone" the 360 as settlement of a lawsuit concerning IBM's infringement of Remington Rand's core memory patents.
10.The UNIVAC 90/30 Series (90/30, 90/25, 90/40): Separately from the 90/60 series, Sperry Univac introduced the Univac 90/30 in about 1975 to provide an upgrade path for 9x00 users and to compete with IBM's System 3. It used a disk operating system and had either a 500 or 2000 lines per minute printer, a card reader, optionally a card punch, a console (Uniscope 100), attached disk drives that had removable disk packs, several 1600 or 6250 BpI tape drives, and possibly a communications controller. The standard disk drive was the 8416 which held a multi-layer platter removable disk pack that held approximately 40 million bytes. The 8418 drive was an enhanced version that supported both 40MB and "double-density" 80MB disk packs. There was also an 8430 drive. The machine had either 1K, 4K or 16K memory chips, and typical machines had between 128 to 512 KiB memory. It ran an OS called OS/3, and could run up to 7 jobs at one time, not counting various OS extensions such as the spooler and telecommunications access (ICAM). It was an upgrade path for folks who had outgrown the IBM System/3. It ran Cobol-74, RPG2, Fortran, and Assembler.
Shortly after the 90/30 was introduced, Sperry Univac introduced the 90/25 which was the same basic hardware, however had an option for a smaller 80 column card reader and was a bit slower (it is said, that the machine executed 3 instructions and then paused to slow it down, as nearly every component was identical to the 90/30). Later a 90/40 model was added which improved upon various performance criteria such as clock rate and maximum main memory capacity.
The Sperry UNIVAC System 80 series: The entire 90/xx series was eventually replaced in 1981 by the System 80, a Sperry-badged, IBM/360-like mainframe actually developed and engineered by Mitsubishi in Japan.
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Bendix G-15
The Bendix G-15 computer was introduced in 1956 by the Bendix Corporation, Computer Division, Los Angeles, California. It was about 5 by 3 by 3 ft (1.5m by 1m by 1m) and weighed about 950 lb (450 kg). The base system, without peripherals, cost $49,500. A working model cost around $60,000. It could also be rented for $1,485 per month. It was meant for scientific and industrial markets. The series was gradually discontinued when Control Data Corporation took over the Bendix computer division in 1963.
The chief designer of the G-15 was Harry Huskey, who had worked with Alan Turing on the ACE in the United Kingdom and on the SWAC in the 1950s. He made most of the design while working as a professor at Berkeley, and other universities. David C. Evans was one of the Bendix engineers on the G-15 project. He would later become famous for his work in computer graphics and for starting up Evans & Sutherland with Ivan Sutherland.
The chief designer of the G-15 was Harry Huskey, who had worked with Alan Turing on the ACE in the United Kingdom and on the SWAC in the 1950s. He made most of the design while working as a professor at Berkeley, and other universities. David C. Evans was one of the Bendix engineers on the G-15 project. He would later become famous for his work in computer graphics and for starting up Evans & Sutherland with Ivan Sutherland.
Architecture
The G-15 was a serial-architecture machine, one of several inspired by the ACE. It used a magnetic drum to simulate the recirculating delay line memory of other serial designs. Each track had a set of read and write heads; as soon as a bit was read off a track, it was re-written on the same track a certain distance away. The length of delay, and thus the number of words on a track, was determined by the spacing of the read and write heads, the delay corresponding to the time required for a section of the drum to travel from the write head to the corresponding read head. Under normal operation, data were written back without change, but this data flow could be intercepted at any time, allowing the machine to update sections of a track as needed.
This arrangement allowed the designers to create "delay lines" of any desired length. In addition to the twenty "long lines" of 108 words each, there were four more short lines of four words each. These short lines recycled at 27 times the rate of the long lines, allowing fast access to frequently needed data. Even the machine's accumulators were implemented as drum lines: three double-word lines used for intermediate storage and double-precision addition, multiplication, and division in addition to a one single-word accumulator. This use of the drum rather than flip-flops for the registers helped to reduce tube count.
A consequence of this design was that, unlike other computers with magnetic drums, the G-15 did not retain its memory when it was shut off. The only permanent tracks were two timing tracks recorded on the drum at the factory. The second track was a backup, as the tracks were liable to erasure if one of their amplifier tubes shorted.
The serial nature of the G-15's memory was carried over into the design of its arithmetic and control circuits. The adders worked on one binary digit at a time, and even the instruction word was designed to minimize the number of bits in an instruction that needed to be retained in flip-flops (to the extent of leveraging another one-word drum line used exclusively for generating address timing signals).
The G-15 had 180 vacuum tube packs and 300 germanium diodes.[1] It had a total of about 450 tubes (mostly dual triodes). [2] Its magnetic drum memory held 2,160 words of twenty-nine bits. Average memory access time was 14.5 milliseconds, but its instruction addressing architecture could reduce this dramatically for well-written programs. Its addition time was 270 microseconds (not counting memory access time). Single-precision multiplication took 2,439 microseconds and double-precision multiplication took 16,700 microseconds.
The G-15 was a serial-architecture machine, one of several inspired by the ACE. It used a magnetic drum to simulate the recirculating delay line memory of other serial designs. Each track had a set of read and write heads; as soon as a bit was read off a track, it was re-written on the same track a certain distance away. The length of delay, and thus the number of words on a track, was determined by the spacing of the read and write heads, the delay corresponding to the time required for a section of the drum to travel from the write head to the corresponding read head. Under normal operation, data were written back without change, but this data flow could be intercepted at any time, allowing the machine to update sections of a track as needed.
This arrangement allowed the designers to create "delay lines" of any desired length. In addition to the twenty "long lines" of 108 words each, there were four more short lines of four words each. These short lines recycled at 27 times the rate of the long lines, allowing fast access to frequently needed data. Even the machine's accumulators were implemented as drum lines: three double-word lines used for intermediate storage and double-precision addition, multiplication, and division in addition to a one single-word accumulator. This use of the drum rather than flip-flops for the registers helped to reduce tube count.
A consequence of this design was that, unlike other computers with magnetic drums, the G-15 did not retain its memory when it was shut off. The only permanent tracks were two timing tracks recorded on the drum at the factory. The second track was a backup, as the tracks were liable to erasure if one of their amplifier tubes shorted.
The serial nature of the G-15's memory was carried over into the design of its arithmetic and control circuits. The adders worked on one binary digit at a time, and even the instruction word was designed to minimize the number of bits in an instruction that needed to be retained in flip-flops (to the extent of leveraging another one-word drum line used exclusively for generating address timing signals).
The G-15 had 180 vacuum tube packs and 300 germanium diodes.[1] It had a total of about 450 tubes (mostly dual triodes). [2] Its magnetic drum memory held 2,160 words of twenty-nine bits. Average memory access time was 14.5 milliseconds, but its instruction addressing architecture could reduce this dramatically for well-written programs. Its addition time was 270 microseconds (not counting memory access time). Single-precision multiplication took 2,439 microseconds and double-precision multiplication took 16,700 microseconds.
Peripherals
One of the G-15's primary output devices was the typewriter with an output speed of about 10 characters per second for numbers (and lower-case hexadecimal characters u-z) and about three characters per second for alphabetical characters. The machine's limited storage precluded much output of anything but numbers; occasionally, paper forms with pre-printed fields or labels were inserted into the typewriter. A faster typewriter unit was also available.
The high-speed photoelectric paper tape reader (250 hexadecimal digits per second on five-channel paper tape for the PR-1; 400 characters from 5-8 channel tape for the PR-2) read programs (and occasionally saved data) from tapes that were often mounted in cartridges for easy loading and unloading. Not unlike magnetic tape, the paper tape data were blocked into runs of 108 words or less since that was the maximum read size. A cartridge could contain many multiple blocks, up to 2500 words (~10 kilobytes).
While the G-15 had an optional high-speed paper tape punch (the PTP-1 at 60 digits per second) for output, the standard punch operated at 17 hex characters per second (510 bytes per minute).
Optionally, the AN-1 "Universal Code Accessory" included the "35-4" Friden Flexowriter and HSR-8 paper tape reader and HSP-8 paper tape punch. The mechanical reader and punch could process paper tapes up to eight channels wide at 110 characters per second.
The CA-1 "Punched Card Coupler" could connect one or two IBM 026 card punches (which were more often used as manual devices) to read cards at 17 columns per second (ca. 12 full cards per minute) or punch cards at 11 columns per second (ca. eight full cards per minute). Partially full cards were processed more quickly with an 80 column per second skip speed). The more expensive CA-2 Punched Card Coupler read and punched cards at a 100 card per minute rate.
The PA-3 pen plotter ran at one inch per second with 200 increments per inch on a paper roll one foot wide by 100 feet long. The optional retractable penholder eliminated "retrace lines".
The MTA-2 could interface up to four drives for half-inch Mylar magnetic tapes, which could store as many as 300,000 words (in blocks no longer than 108 words). The read/write rate was 430 hexadecimal digits per second; the bidirectional search speed was 2500 characters per second.
The DA-1 differential analyzer facilitated solution of differential equations. It contained 108 integrators and 108 constant multipliers, sporting 34 updates per secon
One of the G-15's primary output devices was the typewriter with an output speed of about 10 characters per second for numbers (and lower-case hexadecimal characters u-z) and about three characters per second for alphabetical characters. The machine's limited storage precluded much output of anything but numbers; occasionally, paper forms with pre-printed fields or labels were inserted into the typewriter. A faster typewriter unit was also available.
The high-speed photoelectric paper tape reader (250 hexadecimal digits per second on five-channel paper tape for the PR-1; 400 characters from 5-8 channel tape for the PR-2) read programs (and occasionally saved data) from tapes that were often mounted in cartridges for easy loading and unloading. Not unlike magnetic tape, the paper tape data were blocked into runs of 108 words or less since that was the maximum read size. A cartridge could contain many multiple blocks, up to 2500 words (~10 kilobytes).
While the G-15 had an optional high-speed paper tape punch (the PTP-1 at 60 digits per second) for output, the standard punch operated at 17 hex characters per second (510 bytes per minute).
Optionally, the AN-1 "Universal Code Accessory" included the "35-4" Friden Flexowriter and HSR-8 paper tape reader and HSP-8 paper tape punch. The mechanical reader and punch could process paper tapes up to eight channels wide at 110 characters per second.
The CA-1 "Punched Card Coupler" could connect one or two IBM 026 card punches (which were more often used as manual devices) to read cards at 17 columns per second (ca. 12 full cards per minute) or punch cards at 11 columns per second (ca. eight full cards per minute). Partially full cards were processed more quickly with an 80 column per second skip speed). The more expensive CA-2 Punched Card Coupler read and punched cards at a 100 card per minute rate.
The PA-3 pen plotter ran at one inch per second with 200 increments per inch on a paper roll one foot wide by 100 feet long. The optional retractable penholder eliminated "retrace lines".
The MTA-2 could interface up to four drives for half-inch Mylar magnetic tapes, which could store as many as 300,000 words (in blocks no longer than 108 words). The read/write rate was 430 hexadecimal digits per second; the bidirectional search speed was 2500 characters per second.
The DA-1 differential analyzer facilitated solution of differential equations. It contained 108 integrators and 108 constant multipliers, sporting 34 updates per secon
Software
A problem peculiar to machines with serial memory is the latency of the storage medium: Instructions and data are not always immediately available and, in the worst case, one must wait for the complete recirculation of a delay line to obtain data from a given memory address. The problem was addressed in the G-15 by what the Bendix literature called "minimum-access coding." Each instruction carried with it the address of the next instruction to be executed, allowing the programmer to arrange instructions such that when one instruction completed, the next instruction was about to appear under the read head for its line. Data could be staggered in a similar manner. To aid this process, the coding sheets included a table containing numbers of all addresses; the programmer would cross off each address as it was used.
A symbolic assembler, similar to the IBM 650's SOAP (Symbolic Optimal Assembly Program), was introduced in the late 1950s and included routines for minimum-access coding. Other programming aids included a supervisor program, Intercom, a floating-point interpretive system, and ALGO, an algebraic language designed from the 1958 Preliminary Report of the ALGOL committee. Users also developed their own tools, and a variant of Intercom suited to the needs of civil engineers is said to have circulated.
Floating point was implemented in software. The "Intercom" series of languages provided an easier to program virtual machine that operated in floating point. Instructions to Intercom 500, 550, and 1000 were numerical, six or seven digits in length. Instructions were stored sequentially; the beauty was convenience, not speed. Intercom 1000 even had an optional double-precision version.
A problem peculiar to machines with serial memory is the latency of the storage medium: Instructions and data are not always immediately available and, in the worst case, one must wait for the complete recirculation of a delay line to obtain data from a given memory address. The problem was addressed in the G-15 by what the Bendix literature called "minimum-access coding." Each instruction carried with it the address of the next instruction to be executed, allowing the programmer to arrange instructions such that when one instruction completed, the next instruction was about to appear under the read head for its line. Data could be staggered in a similar manner. To aid this process, the coding sheets included a table containing numbers of all addresses; the programmer would cross off each address as it was used.
A symbolic assembler, similar to the IBM 650's SOAP (Symbolic Optimal Assembly Program), was introduced in the late 1950s and included routines for minimum-access coding. Other programming aids included a supervisor program, Intercom, a floating-point interpretive system, and ALGO, an algebraic language designed from the 1958 Preliminary Report of the ALGOL committee. Users also developed their own tools, and a variant of Intercom suited to the needs of civil engineers is said to have circulated.
Floating point was implemented in software. The "Intercom" series of languages provided an easier to program virtual machine that operated in floating point. Instructions to Intercom 500, 550, and 1000 were numerical, six or seven digits in length. Instructions were stored sequentially; the beauty was convenience, not speed. Intercom 1000 even had an optional double-precision version.
Significance
The G-15 is sometimes described as the first personal computer, because it had the Intercom interpretive system. The title is disputed by other machines, such as the LINC and the PDP-8, and some maintain that only microcomputers, such as those which appeared in the 1970s, can be called personal computers. Nevertheless, the machine's low acquisition and operating costs, and the fact that it did not require a dedicated operator, meant that organizations could allow users complete access to the machine.
Over 400 G-15s were manufactured. About 300 G-15s were installed in the United States and a few were sold in other countries such as Australia and Canada. The machine found a niche in civil engineering, where it was used to solve cut and fill problems. Some have survived and have made their way to computer museums or science and technology museums around the world.
Huskey received one of the last production G15s, fitted with a gold-plated front panel.
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IBM 650
The IBM 650 (photo) was one of IBM’s early computers, and the world’s first mass-produced (photo) computer. It was announced in 1953, and over 2000 systems were produced between the first shipment in 1954 and its final manufacture in 1962. Support for the 650 and its component units was withdrawn in 1969.
The 650 is a two-address, bi-quinary coded decimal machine (both data and addresses were decimal), with memory on a rotating drum. The 650 was marketed to scientific and engineering users as well as users of existing IBM unit record equipment (electro-mechanical punched card-processing machines) upgrading from so-called Calculating Punches, like the IBM 604 model, to computers proper.[1] Because of its relatively low cost and simple programming, the 650 pioneered a wide variety of applications, from modeling submarine crew performance[2] to teaching high school students computer programming.
The 650 is a two-address, bi-quinary coded decimal machine (both data and addresses were decimal), with memory on a rotating drum. The 650 was marketed to scientific and engineering users as well as users of existing IBM unit record equipment (electro-mechanical punched card-processing machines) upgrading from so-called Calculating Punches, like the IBM 604 model, to computers proper.[1] Because of its relatively low cost and simple programming, the 650 pioneered a wide variety of applications, from modeling submarine crew performance[2] to teaching high school students computer programming.
Hardware
The basic 650 system consisted of three components:
Console Unit (IBM 650)
Power Unit (IBM 655)
Card Reader/Punch Unit (IBM 533 or IBM 537)
Optional components:
Disk Unit (IBM 355) Systems with a disk unit were known as a IBM RAMAC 650 Data Processing System
Card Reader Unit (IBM 543)
Card Punch Unit (IBM 544)
Control Unit (IBM 652) Magnetic Tape Controller
Auxiliary Unit (IBM 653) Core storage, index registers, floating point arithmetic
Auxiliary Alphabetic Unit (IBM 654)
Magnetic Tape Unit (IBM 727)
Inquiry Station (IBM 838)
Tape To Card Punch IBM 46 Model 3
Tape To Card Punch IBM 47 Model 3
Alphabetical Accounting Machine IBM 407
The rotating drum memory (photo) provided 2,000 signed 10-digit words of memory (5 characters per word) at addresses 0000 to 1999. A Model 4, introduced in 1959, doubled the drum capacity to 4,000 words.[3] A word could not be accessed until its location on the drum surface passed under the read/write heads during rotation (rotating at 12,500 rpm, the non-optimized average access time was 2.5 ms). Because of this timing restriction, the second address in each instruction word was the address of the next instruction. Programs could be optimized by placing instructions around the drum based on the expected execution time of the previous instruction. One specialized instruction, 'Table lookup', could high-equal compare a reference 10 digit word with 46 consecutive following words on the drum in one 5ms revolution and then switch to the next track in time for the next 46 words (there were fifty words per track/revolution). This feat was about one third the speed of a one-thousand times faster binary machine in 1963 (1500 microsecs on the IBM 7040 to 5000 microsecs on the IBM 650 for looking up 46 entries as long as both were programmed in assembler. One higher level language made the IBM 7040 dramatically slower at table-look-up.
The optional Auxiliary Unit (IBM 653), was introduced on May 3, 1955, providing up to three features:
60 10-digit words of magnetic core memory at addresses 9000 to 9059; a small fast memory (this device gave a memory access time of 96µs, a 26-fold raw improvement relative to the rotating drum), needed for a tape and disk I/O buffer
3 4-digit index registers at addresses 8005 to 8007; drum addresses were indexed by adding 2000, 4000 or 6000 to them, core addresses were indexed by adding 0200, 0400 or 0600 to them. If the system had the 4000 word memory drum then indexing was by adding 4000 to the first address for index reg A, adding 4000 to the second address for index reg B, and by adding 4000 to each of the two addresses for index reg C. (the indexing for 4000 word systems only applied to the first address). The 4000 word systems required transistorized read/write circuitry for the drum memory and were available before 1963.
Floating point – arithmetic instructions with 8 digit mantissa and 2 digit characteristic (offset exponent) – MMMMMMMMCC, providing a range of ±0.00000001E-50 to ±0.99999999E+49
The IBM 533 reader punch unit could only read a maximum of 26 columns of alphanumerics from cards in mostly fixed columns. An expansion allowed more but certainly not over 50, as only ten words could be read from a card (5 characters per word).
The IBM 650 (pictured here) at the Haus zur Geschichte der IBM Datenverarbeitung (House for the History of IBM Data Processing), Sindelfingen, is still running (as of May 2004) and will process an income tax program of the time, with input and output on punched cards.
The IBM 7070, announced 1960, was designed to provide a "transistorized IBM 650" upgrade path. The IBM 1620, introduced in 1959, addressed the lower end of the market. Both were decimal machines, but neither were instruction set compatible.
The basic 650 system consisted of three components:
Console Unit (IBM 650)
Power Unit (IBM 655)
Card Reader/Punch Unit (IBM 533 or IBM 537)
Optional components:
Disk Unit (IBM 355) Systems with a disk unit were known as a IBM RAMAC 650 Data Processing System
Card Reader Unit (IBM 543)
Card Punch Unit (IBM 544)
Control Unit (IBM 652) Magnetic Tape Controller
Auxiliary Unit (IBM 653) Core storage, index registers, floating point arithmetic
Auxiliary Alphabetic Unit (IBM 654)
Magnetic Tape Unit (IBM 727)
Inquiry Station (IBM 838)
Tape To Card Punch IBM 46 Model 3
Tape To Card Punch IBM 47 Model 3
Alphabetical Accounting Machine IBM 407
The rotating drum memory (photo) provided 2,000 signed 10-digit words of memory (5 characters per word) at addresses 0000 to 1999. A Model 4, introduced in 1959, doubled the drum capacity to 4,000 words.[3] A word could not be accessed until its location on the drum surface passed under the read/write heads during rotation (rotating at 12,500 rpm, the non-optimized average access time was 2.5 ms). Because of this timing restriction, the second address in each instruction word was the address of the next instruction. Programs could be optimized by placing instructions around the drum based on the expected execution time of the previous instruction. One specialized instruction, 'Table lookup', could high-equal compare a reference 10 digit word with 46 consecutive following words on the drum in one 5ms revolution and then switch to the next track in time for the next 46 words (there were fifty words per track/revolution). This feat was about one third the speed of a one-thousand times faster binary machine in 1963 (1500 microsecs on the IBM 7040 to 5000 microsecs on the IBM 650 for looking up 46 entries as long as both were programmed in assembler. One higher level language made the IBM 7040 dramatically slower at table-look-up.
The optional Auxiliary Unit (IBM 653), was introduced on May 3, 1955, providing up to three features:
60 10-digit words of magnetic core memory at addresses 9000 to 9059; a small fast memory (this device gave a memory access time of 96µs, a 26-fold raw improvement relative to the rotating drum), needed for a tape and disk I/O buffer
3 4-digit index registers at addresses 8005 to 8007; drum addresses were indexed by adding 2000, 4000 or 6000 to them, core addresses were indexed by adding 0200, 0400 or 0600 to them. If the system had the 4000 word memory drum then indexing was by adding 4000 to the first address for index reg A, adding 4000 to the second address for index reg B, and by adding 4000 to each of the two addresses for index reg C. (the indexing for 4000 word systems only applied to the first address). The 4000 word systems required transistorized read/write circuitry for the drum memory and were available before 1963.
Floating point – arithmetic instructions with 8 digit mantissa and 2 digit characteristic (offset exponent) – MMMMMMMMCC, providing a range of ±0.00000001E-50 to ±0.99999999E+49
The IBM 533 reader punch unit could only read a maximum of 26 columns of alphanumerics from cards in mostly fixed columns. An expansion allowed more but certainly not over 50, as only ten words could be read from a card (5 characters per word).
The IBM 650 (pictured here) at the Haus zur Geschichte der IBM Datenverarbeitung (House for the History of IBM Data Processing), Sindelfingen, is still running (as of May 2004) and will process an income tax program of the time, with input and output on punched cards.
The IBM 7070, announced 1960, was designed to provide a "transistorized IBM 650" upgrade path. The IBM 1620, introduced in 1959, addressed the lower end of the market. Both were decimal machines, but neither were instruction set compatible.
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