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37-783: 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 (where his graduate students included Niklaus Wirth ), 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 G-15

74-472: A ' Zelig -like character, present at some of computing's greatest moments.'" Huskey married Velma Roeth (died 1991) in 1939 and had four children. In 1994, he married Nancy Grindstaff (died in 2016). He lived in Santa Cruz, California . Huskey appeared with a junk dealer as the third pair of contestants in the 10 May 1950 episode of Groucho Marx 's radio show You Bet Your Life . He was described as

111-432: A 100-card-per-minute rate. The PA-3 pen plotter runs at 1 inch per second with 200 increments per inch on a paper roll 1 foot wide by 100 feet long. The optional retractable pen-holder eliminates "retrace lines". The MTA-2 can interface up to four drives for half-inch Mylar magnetic tapes, which can store as many as 300,000 words (in blocks no longer than 108 words). The read/write rate is 430 hexadecimal digits per second;

148-401: A certain distance away. The length of delay, and thus the number of words on a track, is 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 are written back without change, but this data flow can be intercepted at any time, allowing

185-435: 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. This was the first computer that Ken Thompson ever used. A Bendix G-15 was used at Fremont High School (Oakland Unified School District) in

222-493: A one single-word accumulator. This use of the drum rather than flip-flops for the registers helped to reduce vacuum tube count. A consequence of this design was that, unlike other computers with magnetic drums, the G-15 does not retain its memory when it is shut off. The only permanent tracks are two timing tracks recorded on the drum at the factory. The second track is a backup, as the tracks are liable to erasure if one of their amplifier tubes shorted out. The serial nature of

259-478: A total of about 450 tubes (mostly dual triodes). Its magnetic drum memory holds 2,160 words of twenty-nine bits . Average memory access time is 14.5 milliseconds , but its instruction addressing architecture can reduce this dramatically for well-written programs. Its addition time is 270 microseconds (not counting memory access time). Single-precision multiplication takes 2,439 microseconds and double-precision multiplication takes 16,700 microseconds. One of

296-455: Is about to appear under the read head for its line. Data can be staggered in a similar manner. To aid this process, the coding sheets include a table containing numbers of all addresses; the programmer can cross off each address as it is used. Bendix has an operating system of the same name. A symbolic assembler, similar to the IBM 650 's Symbolic Optimal Assembly Program (SOAP), was introduced in

333-499: Is approximately 1000. The binary interpretation of metric prefixes is still prominently used by the Microsoft Windows operating system. Binary interpretation is also used for random-access memory capacity, such as main memory and CPU cache size, due to the prevalent binary addressing of memory. The binary meaning of the kilobyte for 1024 bytes typically uses the symbol KB, with an uppercase letter K . The B

370-430: Is implemented in software. The "Intercom" series of languages provide an easier to program virtual machine that operates in floating point. Instructions to Intercom 500, 550, and 1000 are numerical, six or seven digits in length. Instructions are stored sequentially; the beauty is convenience, not speed. Intercom 1000 even has an optional double-precision version. As mentioned above the machine uses hexadecimal numbers, but

407-724: Is now in the Smithsonian Institution in Washington, D.C. After five years at the National Bureau of Standards, Huskey joined the faculty of the University of California, Berkeley in 1954 and then University of California, Santa Cruz from 1966. He cofounded the computer and information science program at UC Santa Cruz in 1967. He became director of its computer center. In 1986, UC Santa Cruz named him professor emeritus. While at Berkeley, he supervised

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444-518: Is sometimes omitted in informal use. For example, a processor with 65,536 bytes of cache memory might be said to have "64 K" of cache. In this convention, one thousand and twenty-four kilobytes (1024 KB) is equal to one megabyte (1 MB), where 1 MB is 1024  bytes. In December 1998, the IEC addressed such multiple usages and definitions by creating prefixes such as kibi, mebi, gibi, etc., to unambiguously denote powers of 1024. Thus

481-1109: Is the maximum read size. A cartridge can contain many multiple blocks, up to 2500 words (~10 kilobytes ). While there is an optional high-speed paper tape punch (the PTP-1 at 60 digits per second) for output, the standard punch operates 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 can process paper tapes up to eight channels wide at 110 characters per second. The CA-1 "Punched Card Coupler" can connect one or two IBM 026 card punches (which were more often used as manual devices) to read cards at 17 columns per second (approximately 12 full cards per minute) or punch cards at 11 columns per second (approximately 8 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 reads and punches cards at

518-725: The Mathematisch Centrum in Amsterdam , Maurice Wilkes of Cambridge University . Huskey was Professor Emeritus at the University of California after his retirement at the age of 70 in 1986. In 1994 he was inducted as a Fellow of the Association for Computing Machinery . Dag Spicer, senior curator at the Computer History Museum in Mountain View, California , "described Dr. Huskey as

555-824: The Pilot ACE computer with Alan Turing and others. He was also involved with the EDVAC and SEAC computer projects. Huskey designed and managed the construction of the Standards Western Automatic Computer (SWAC) at the National Bureau of Standards in Los Angeles (1949–1953). He also designed the G-15 computer for Bendix Aviation Corporation , a 950 pounds (430 kg) machine, operable by one person. He had one at his home that

592-573: The 1964-65 school year for the senior seminar math class. Students were taught the fundamentals of programming. One such exercise was the calculation of a square root using the method of Newtonian approximation. A Bendix G-15 was still in use for the UC Berkeley extension summer class in programming, at Oakland Technical High School, in 1970. A Bendix G-15 was used at the Summer Science Program , at least in 1962 and 1963. One of

629-487: The 1970s, can be called personal computers. Nevertheless, the machine's low acquisition and operating costs, and the fact that it does 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

666-518: The Centro de Calculo in Mexico City , John Makepeace Bennett of the University of Sydney , Launor Carter of SDC - author of the subsequent Carter Report on Computer Technology for Schools, David Evans of UC Berkeley , Bruce Gilchrist of IBM-SBC, Clay Perry of UC San Diego , Sigeiti Moriguti of the University of Tokyo , Gio Wiederhold , also of UC Berkeley, Adriaan van Wijngaarden of

703-459: The G-15's memory was carried over into the design of its arithmetic and control circuits. The adders work 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 has 180 vacuum tube packs and 3000 germanium diodes . It has

740-428: The G-15's primary output devices is 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 precludes much output of anything but numbers; occasionally, paper forms with pre-printed fields or labels were inserted into the typewriter. A faster typewriter unit

777-570: The Headmaster, Stanford University, Caltech, and Harvey Mudd College, in response to Sputnik. The curriculum was focused on astronomy, with a lab project that consists of photographing an asteroid three times and computing its orbit. It is now a nonprofit program wholly owned and operated by alumni, offering biochemistry, genomics, and synthetic chemistry, in addition to the original astronomy (now astrophysics) program. Harry Huskey Harry Douglas Huskey (January 19, 1916 – April 9, 2017)

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814-616: The Problem of Geöcze . Huskey taught mathematics to U.S. Navy students at the University of Pennsylvania and then worked part-time on the early ENIAC and EDVAC computers in 1945. This work represented his first formal introduction to computers, according to his obituary in The New York Times . He visited the National Physical Laboratory (NPL) in the United Kingdom for a year and worked on

851-405: The bidirectional search speed is 2500 characters per second. The DA-1 differential analyzer facilitates solution of differential equations. It contains 108 integrators and 108 constant multipliers, sporting 34 updates per second. 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,

888-480: The designer of an " electronic brain ". They selected the "state category" and missed the final question when they failed to identify Iowa as the state north of Missouri. In 2013, the Computer History Museum named him a Museum Fellow "for his seminal work on early and important computing systems and a lifetime of service to computer education." Kilobyte The kilobyte is a multiple of

925-486: The late 1950s and includes routines for minimum-access coding. Other programming aids include a supervisor program, a floating-point interpretive system named "Intercom", 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 arithmetic

962-406: The machine must wait for the complete recirculation of a delay line to obtain data from a given memory address. The problem is addressed in the G-15 by what the Bendix literature calls "minimum-access coding". Each instruction carries with it the address of the next instruction to be executed, allowing the programmer to arrange instructions such that when one instruction completes, the next instruction

999-563: The machine to update sections of a track as needed. This arrangement allows the designers to create "delay lines" of any desired length. In addition to the twenty "long lines" of 108 words each, there are four more short lines of four words each. These short lines recycle at 27 times the rate of the long lines, allowing fast access to frequently needed data. Even the machine's accumulators are implemented as drum lines: three double-word lines are used for intermediate storage and double-precision addition, multiplication, and division in addition to

1036-643: The prevalence of sizes that are powers of two in modern digital memory architectures, coupled with the coincidence that 2 differs from 10 by less than 2.5%. A kibibyte is 1024 bytes. In the International System of Units (SI) the metric prefix kilo means 1,000 (10 ); therefore, one kilobyte is 1000 bytes. The unit symbol is kB. This is the definition recommended by the International Electrotechnical Commission (IEC). This definition, and

1073-527: The related definitions of the prefixes mega ( 1,000,000 ), giga ( 1,000,000,000 ), etc., are most commonly used for data transfer rates in computer networks , internal bus, hard drive and flash media transfer speeds, and for the capacities of most storage media , particularly hard disk drives , flash -based storage, and DVDs . It is also consistent with the other uses of the metric prefixes in computing, such as CPU clock speeds or measures of performance . The international standard IEC 80000-13 uses

1110-495: The research of pioneering programming language designer Niklaus Wirth , who gained his PhD in 1963. During 1963-1964 Prof. Huskey participated in establishing the Computer Center at IIT Kanpur and convened a meeting there with many pioneers of computing technology. Participants included Forman Acton of Princeton University , Robert Archer of Case Institute of Technology , S. Barton of CDC, Australia, S. Beltran from

1147-531: The teaching assistants, a graduate student at UCLA, reported that one was used to check syntax of Fortran programs before they could be submitted to the 7094. The son of the engineer who arranged the use of the computer was a student in 1963. The program began as a six week residential science enrichment course for advanced rising high-school seniors, at the Thacher School in Ojai, CA, as a collaboration between

Bendix G-15 - Misplaced Pages Continue

1184-405: The term "byte" to mean eight bits (1 B = 8 bit). Therefore, 1 kB = 8000 bit. One thousand kilobytes (1000 kB) is equal to one megabyte (1 MB), where 1 MB is one million bytes. The term 'kilobyte' has traditionally been used to refer to 1024 bytes (2  B). The usage of the metric prefix kilo for binary multiples arose as a convenience, because 1024

1221-451: The unit byte for digital information . The International System of Units (SI) defines the prefix kilo as a multiplication factor of 1000 (10 ); therefore, one kilobyte is 1000 bytes. The internationally recommended unit symbol for the kilobyte is kB . In some areas of information technology , particularly in reference to random-access memory capacity, kilobyte instead typically refers to 1024 (2 ) bytes. This arises from

1258-700: The user never has to deal with this in normal programming. The user programs use the decimal numbers while the OS resides in the higher addresses. The G-15 is sometimes described as the first personal computer , because it has the Intercom interpretive system. The title is disputed by other machines, such as the LGP-30 (shipped in late 1956), and the DEC LINC (March 1962) and PDP-8 (March 1965), while some maintain that only microcomputers, such as those which appeared in

1295-522: 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 are blocked into runs of 108 words or less since that

1332-647: Was an American computer design pioneer. Huskey was born in Whittier , in the Smoky Mountains region of North Carolina and grew up in Idaho . He received his bachelor's degree in mathematics and physics at the University of Idaho . He was the first member of his family to attend college. He gained his Master's and then his PhD in 1943 from the Ohio State University on Contributions to

1369-480: Was inspired by the Automatic Computing Engine (ACE). It is a serial-architecture machine , in which the main memory is a magnetic drum . It uses the drum as a recirculating delay-line memory , in contrast to the analog delay line implementation in other serial designs. Each track has a set of read and write heads; as soon as a bit was read off a track, it is re-written on the same track

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