The IBM 7090 is a second-generation transistorized version of the earlier IBM 709 vacuum tube mainframe computer, designed for "large-scale scientific and technological applications". The 7090 is the third member of the IBM 700/7000 series scientific computers; the first 7090 installation was in November 1959. In 1960, a typical system could be rented for $63,500 a month; the 7090 uses a 36-bit word length, with an address space of 32,768 words. It operates with a basic memory cycle of 2.18 μs, using the IBM 7302 Core Storage core memory technology from the IBM 7030 project. With a processing speed of around 100 Kflop/s, the 7090 is six times faster than the 709, could be rented for half the price. 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, which because of the sound when spoken shifted to the nomenclature 7090.
The related machines such as the 7070 and other 7000 series equipment were sometimes called by names of digit - digit - decade. An upgraded version, the IBM 7094, was first installed in September 1962, it has seven index registers, instead of three on the earlier machines. The 7094 console has a distinctive box on top. Photos The 7094 introduced double-precision floating point and additional instructions, but is backward compatible with the 7090. Minor changes in instruction formats the way the additional index registers are addressed, sometimes caused problems. On the earlier models, when more than one bit is set in the tag field, the contents of the two or three selected index registers are ORed, not added together, before the decrement takes place. On the 7094, if the three-bit tag field is not zero, it selects just one of seven index registers, however the "or" behavior remains available in a "multiple tag" compatibility mode. In April 1964, the first 7094 II was installed, which had 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 instance of pipelined design.
In 1963, IBM introduced two new, lower cost machines called the IBM 7040 and 7044. They have a 36-bit architecture based on the 7090, but with some instructions omitted or optional, simplified input/output that allows the use of more modern, higher performance peripherals from the IBM 1400 series; the 7094/7044 Direct Coupled System was developed by an IBM customer, the Aerospace Corporation, seeking greater cost efficiency and scheduling flexibility than IBM's IBSYS tape operating system provided. DCS used a less expensive IBM 7044 to handle Input/Output with the 7094 performing computation. Aerospace developed the Direct Couple operating system, an extension to IBSYS, shared with other IBM customers. IBM introduced the DCS as a product; the 7090 uses more than 50,000 germanium alloy-junction transistors and germanium diffused junction drift transistors. The 7090 uses the Standard Modular System cards using current-mode logic some using diffused junction drift transistors; the basic instruction format is the same as the IBM 709, a three-bit prefix, 15-bit decrement, three-bit tag, 15-bit address.
The prefix field specifies the class of instruction. The decrement field contains an immediate operand to modify the results of the operation, or is used to further define the instruction type; the three bits of the tag specify three index registers, the contents of which are subtracted from the address to produce an effective address. The address field contains either an immediate operand. Fixed-point numbers are stored in binary sign/magnitude format. Single-precision floating-point numbers have a magnitude sign, an eight-bit excess-128 exponent and a 27-bit magnitude Double-precision floating-point numbers, introduced on the 7094, have a magnitude sign, an eight-bit excess-128 exponent, a 54-bit magnitude; the double-precision number is stored in memory in an even-odd pair of consecutive words. Alphanumeric characters are six-bit BCD, packed six to a word. Octal notation is used in programming; the 7090 series features a data channel architecture for input and output, a forerunner of modern direct memory access I/O.
Up to eight data channels can be attached, with up to ten IBM 729 tape drives attached to each channel. The data channels have their own limited set of operations called commands; these are used with tape storage as well as card units and printers, offered high performance for the time. Printing and punched card I/O, employed the same modified unit record equipment introduced with the 704 and was slow, it became common to use a less expensive IBM 1401 computer to read cards onto magnetic tape for transfer to the 7090/94. Output would be spooled onto tape and transferred to the 1401 for printing or card punching using its much faster peripherals, notably the IBM 1403 line printer. IBM introduced the 7094/7044 Direct Coupled System, using data channel to data channel communication, with the 7094 pri
"Hello, World!" program
A "Hello, World!" program is a computer program that outputs or displays the message "Hello, World!". Because it is simple in most programming languages, it is used to illustrate the basic syntax of a programming language and is the first program that those learning to code write. A "Hello, World!" program is traditionally used to introduce novice programmers to a programming language. "Hello, world!" is traditionally used in a sanity test to make sure that a computer language is installed, that the operator understands how to use it. While small test programs have existed since the development of programmable computers, the tradition of using the phrase "Hello, world!" as a test message was influenced by an example program in the seminal book The C Programming Language. The example program from that book prints "hello, world", was inherited from a 1974 Bell Laboratories internal memorandum by Brian Kernighan, Programming in C: A Tutorial: The C version was preceded by Kernighan's own 1972 A Tutorial Introduction to the Language B, where the first known version of the program is found in an example used to illustrate external variables: main a'hell'.
The phrase is divided into multiple variables because in B, a character constant is limited to four ASCII characters. The previous example in the tutorial printed hi! on the terminal, the phrase hello, world! was introduced as a longer greeting that required several character constants for its expression. The Jargon File claims that hello, world originated instead with BCPL; this claim is supported by the archived notes of the inventors of BCPL, Prof. Brian Kernighan at Princeton and Martin Richards at Cambridge. For modern languages, world programs vary in sophistication. For example, the Go programming language introduced a multilingual program, Sun demonstrated a Java hello, world based on scalable vector graphics, the XL programming language features a spinning Earth hello, world using 3D graphics. While some languages such as Perl, Python or Ruby may need only a single statement to print "hello, world", a low-level assembly language may require dozens of commands. Mark Guzdial and Elliot Soloway have suggested that the "hello, world" test message may be outdated now that graphics and sound can be manipulated as as text.
There are many variations on the punctuation and casing of the phrase. Variations include the presence or absence of the comma and exclamation mark, the capitalization of the'H', both the'H' and the'W', or neither; some languages are forced to implement different forms, such as "HELLO WORLD", on systems that support only capital letters, while many "hello, world" programs in esoteric languages print out a modified string. For example, the first non-trivial Malbolge program printed "HEllO WORld", this having been determined to be good enough. There are variations in spirit, as well. Functional programming languages, like Lisp, ML and Haskell, tend to substitute a factorial program for Hello, World, as functional programming emphasizes recursive techniques, whereas the original examples emphasize I/O, which violates the spirit of pure functional programming by producing side effects. Languages otherwise capable of Hello, World may be used in embedded systems, where text output is either difficult or nonexistent.
For devices such as microcontrollers, field-programmable gate arrays, CPLD's, "Hello, World" may thus be substituted with a blinking LED, which demonstrates timing and interaction between components. The Debian and Ubuntu Linux distributions provide the "hello, world" program through the apt packaging system. While of itself useless, it serves as a sanity check and a simple example to newcomers of how to install a package, it is more useful for developers, however, as it provides an example of how to create a.deb package, either traditionally or using debhelper, the version of hello used, GNU Hello, serves as an example of how to write a GNU program. Time to "Hello World" is a metric for how long it takes to get a "Hello World" program running from scratch in a given programming language. "99 Bottles of Beer" as used in computer science Foobar Java Pet Store Just another Perl hacker List of basic computer science topics Trabb Pardo-Knuth algorithm List of hello world programs at Wikibooks Rösler, Wolfram.
"Hello World Collection". Helloworldcollection.de. "Hello world/Text". Rosetta Code. "Unsung Heroes of IT / Part One: Brian Kernighan". TheUnsungHeroesOfIT.com. Archived from the original on 2016-03-26. Retrieved 2014-08-23
ASCII art is a graphic design technique that uses computers for presentation and consists of pictures pieced together from the 95 printable characters defined by the ASCII Standard from 1963 and ASCII compliant character sets with proprietary extended characters. The term is loosely used to refer to text based visual art in general. ASCII art can be created with any text editor, is used with free-form languages. Most examples of ASCII art require a fixed-width font such as Courier for presentation. Among the oldest known examples of ASCII art are the creations by computer-art pioneer Kenneth Knowlton from around 1966, working for Bell Labs at the time. "Studies in Perception I" by Ken Knowlton and Leon Harmon from 1966 shows some examples of their early ASCII art. ASCII art was invented, in large part, because early printers lacked graphics ability and thus characters were used in place of graphic marks. To mark divisions between different print jobs from different users, bulk printers used ASCII art to print large banners, making the division easier to spot so that the results could be more separated by a computer operator or clerk.
ASCII art was used in early e-mail when images could not be embedded. Since 1867 typewriters have been used for creating visual art. TTY stands for "TeleTYpe" or "TeleTYpewriter" and is known as Teleprinter or Teletype. RTTY stands for Radioteletype. According to a chapter in the "RTTY Handbook", text images have been sent via teletypewriter as early as 1923. However, none of the "old" RTTY art has been discovered yet. What is known is that text images appeared on radioteletype in the 1960s and the 1970s. In the 1960s, Andries van Dam published a representation of an electronic circuit produced on an IBM 1403 line printer. At the same time, Kenneth Knowlton was producing realistic images on line printers, by overprinting several characters on top of one another. Note that it was not ASCII art in a sense that the 1403 was driven by an EBCDIC-coded platform and the character sets and trains available on the 1403 were derived from EBCDIC rather than ASCII, despite some glyphs commonalities; the widespread usage of ASCII art can be traced to the computer bulletin board systems of the late 1970s and early 1980s.
The limitations of computers of that time period necessitated the use of text characters to represent images. Along with ASCII's use in communication, however, it began to appear in the underground online art groups of the period. An ASCII comic is a form of webcomic. In place of images in a regular comic, ASCII art is used, with the text or dialog placed underneath. During the 1990s, graphical browsing and variable-width fonts became popular, leading to a decline in ASCII art. Despite this, ASCII art continued to survive through online MUDs, an acronym for "Multi-User Dungeon", Internet Relay Chat, E-mail, message boards and other forms of online communication which employ the needed fixed-width. ASCII and more ANSI were staples of the early technological era. Over the years, warez groups began to enter the ASCII art scene. Warez groups release.nfo files with their software, cracks or other general software reverse-engineering releases. The ASCII art will include the warez group's name and maybe some ASCII borders on the outsides of the release notes, etc.
BBS systems were based on ASCII and ANSI art, as were most DOS and similar console applications, the precursor to AOL. ASCII art is used wherever text can be more printed or transmitted than graphics, or in some cases, where the transmission of pictures is not possible; this includes typewriters, non-graphic computer terminals, printer separators, in early computer networking, e-mail, Usenet news messages. ASCII art is used within the source code of computer programs for representation of company or product logos, flow control or other diagrams. In some cases, the entire source code of a program is a piece of ASCII art – for instance, an entry to one of the earlier International Obfuscated C Code Contest is a program that adds numbers, but visually looks like a binary adder drawn in logic ports; some electronic schematic archives represent the circuits using ASCII art. Examples of ASCII-style art predating the modern computer era can be found in the June 1939, July 1948 and October 1948 editions of Popular Mechanics."0verkill" is a 2D platform multiplayer shooter game designed in color ASCII art.
MPlayer and VLC media player can display videos as ASCII art through the AAlib library. ASCII art is used in the making of DOS-based ZZT games. Many game walkthrough guides come as part of a basic.txt file. Such as below, word art is created using backslashes and other ASCII values in order to create the illusion of 3D. Different techniques could be used in ASCII art to obtain different artistic effects. Electronic circuits and diagrams were implemented by typewriter or teletype and provided the pretense for ASCII. "Typewriter-style" lettering, made from individual letter characters: H H EEEEE L L OOO W W OOO RRRR L DDDD!! H H E L L O O W W W O O R R L D D!! HHHHH EEEEE L L O O W W W O O RRRR L D D!! H H E L L O O, W W O O R R L D D
Mainframe computers or mainframes are computers used by large organizations for critical applications. They are larger and have more processing power than some other classes of computers: minicomputers, servers and personal computers; the term referred to the large cabinets called "main frames" that housed the central processing unit and main memory of early computers. The term was used to distinguish high-end commercial machines from less powerful units. Most large-scale computer system architectures were established in the 1960s, but continue to evolve. Mainframe computers are used as servers. Modern mainframe design is characterized less by raw computational speed and more by: Redundant internal engineering resulting in high reliability and security Extensive input-output facilities with the ability to offload to separate engines Strict backward compatibility with older software High hardware and computational utilization rates through virtualization to support massive throughput. Hot-swapping of hardware, such as processors and memory.
Their high stability and reliability enable these machines to run uninterrupted for long periods of time, with mean time between failures measured in decades. Mainframes have high availability, one of the primary reasons for their longevity, since they are used in applications where downtime would be costly or catastrophic; the term reliability and serviceability is a defining characteristic of mainframe computers. Proper planning and implementation is required to realize these features. In addition, mainframes are more secure than other computer types: the NIST vulnerabilities database, US-CERT, rates traditional mainframes such as IBM Z, Unisys Dorado and Unisys Libra as among the most secure with vulnerabilities in the low single digits as compared with thousands for Windows, UNIX, Linux. Software upgrades require setting up the operating system or portions thereof, are non-disruptive only when using virtualizing facilities such as IBM z/OS and Parallel Sysplex, or Unisys XPCL, which support workload sharing so that one system can take over another's application while it is being refreshed.
In the late 1950s, mainframes had only a rudimentary interactive interface, used sets of punched cards, paper tape, or magnetic tape to transfer data and programs. They operated in batch mode to support back office functions such as payroll and customer billing, most of which were based on repeated tape-based sorting and merging operations followed by line printing to preprinted continuous stationery; when interactive user terminals were introduced, they were used exclusively for applications rather than program development. Typewriter and Teletype devices were common control consoles for system operators through the early 1970s, although supplanted by keyboard/display devices. By the early 1970s, many mainframes acquired interactive user terminals operating as timesharing computers, supporting hundreds of users along with batch processing. Users gained access through keyboard/typewriter terminals and specialized text terminal CRT displays with integral keyboards, or from personal computers equipped with terminal emulation software.
By the 1980s, many mainframes supported graphic display terminals, terminal emulation, but not graphical user interfaces. This form of end-user computing became obsolete in the 1990s due to the advent of personal computers provided with GUIs. After 2000, modern mainframes or phased out classic "green screen" and color display terminal access for end-users in favour of Web-style user interfaces; the infrastructure requirements were drastically reduced during the mid-1990s, when CMOS mainframe designs replaced the older bipolar technology. IBM claimed that its newer mainframes reduced data center energy costs for power and cooling, reduced physical space requirements compared to server farms. Modern mainframes can run multiple different instances of operating systems at the same time; this technique of virtual machines allows applications to run as if they were on physically distinct computers. In this role, a single mainframe can replace higher-functioning hardware services available to conventional servers.
While mainframes pioneered this capability, virtualization is now available on most families of computer systems, though not always to the same degree or level of sophistication. Mainframes can add or hot swap system capacity without disrupting system function, with specificity and granularity to a level of sophistication not available with most server solutions. Modern mainframes, notably the IBM zSeries, System z9 and System z10 servers, offer two levels of virtualization: logical partitions and virtual machines. Many mainframe customers run two machines: one in their primary data center, one in their backup data center—fully active active, or on standby—in case there is a catastrophe affecting the first building. Test, development and production workload for applications and databases can run on a single machine, except for large demands where the capacity of one machine might be limiting; such a two-mainframe installation can support continuous business service, avoiding both planned and unplanned outages.
In practice many customers use multiple mainframes linked either by Parallel Sysplex and shared DASD, or with shared, geographically dispersed storage provided by EMC
Brian Wilson Kernighan is a Canadian computer scientist. He worked at Bell Labs and contributed to the development of Unix alongside Unix creators Ken Thompson and Dennis Ritchie. Kernighan's name became known through co-authorship of the first book on the C programming language with Dennis Ritchie. Kernighan affirmed, he authored many Unix programs, including ditroff. Kernighan is coauthor of the AMPL programming languages; the "K" of K&R C and the "K" in AWK both stand for "Kernighan". In collaboration with Shen Lin he devised well-known heuristics for two NP-complete optimization problems: graph partitioning and the travelling salesman problem. In a display of authorial equity, the former is called the Kernighan–Lin algorithm, while the latter is known as the Lin–Kernighan heuristic. Kernighan has been a Professor in the Computer Science Department of Princeton University since 2000, he is the Undergraduate Department Representative. Kernighan was born in Toronto, he attended the University of Toronto between 1960 and 1964, earning his Bachelor's degree in engineering physics.
He received his PhD in electrical engineering from Princeton University in 1969 for research supervised by Peter Weiner. Kernighan has held a professorship in the Department of Computer Science at Princeton since 2000; each fall he teaches a course called "Computers in Our World", which introduces the fundamentals of computing to non-majors. Kernighan was the software editor for Prentice Hall International, his "Software Tools" series spread the essence of "C/Unix thinking" with makeovers for BASIC, FORTRAN, Pascal, most notably his "Ratfor" was put in the public domain. He has said that if stranded on an island with only one programming language it would have to be C. Kernighan coined the term helped popularize Thompson's Unix philosophy. Kernighan is known as a coiner of the expression "What You See Is All You Get", a sarcastic variant of the original "What You See Is What You Get". Kernighan's term is used to indicate that WYSIWYG systems might throw away information in a document that could be useful in other contexts.
Kernighan's original 1978 implementation of Hello, World! was sold at The Algorithm Auction, the world's first auction of computer algorithms. In 1996, Kernighan taught CS50, the Harvard University introductory course in Computer Science. Other achievements during his career include: Brian Kernighan's home page at Bell Labs "Why Pascal is Not My Favorite Programming Language" — By Brian Kernighan, AT&T Bell Labs, 2 April 1981 "Leap In and Try Things" — Interview with Brian Kernighan — on "Harmony at Work Blog", October 2009. An Interview with Brian Kernighan — By Mihai Budiu, for PC Report Romania, August 2000 "Transcript of an interview with Brian Kernighan". Archived from the original on 2009-04-28. Retrieved 2016-03-31. – Interview by"Michael S. Mahoney". Archived from the original on 2009-05-28. Retrieved 2016-03-31. Video — TechNetCast At Bell Labs: Dennis Ritchie and Brian Kernighan Video — "Assembly for the Class of 2007:'D is for Digital and Why It Matters'" A Descent into Limbo by Brian Kernighan Photos of Brian Kernighan Works by Brian Kernighan at Open Library Video interview with Brian Kernighan for Princeton Startup TV The Setup, Brian Kernighan
University of Michigan
The University of Michigan simply referred to as Michigan, is a public research university in Ann Arbor, Michigan. The university is Michigan's oldest; the school was moved to Ann Arbor in 1837 onto 40 acres of. Since its establishment in Ann Arbor, the university campus has expanded to include more than 584 major buildings with a combined area of more than 34 million gross square feet spread out over a Central Campus and North Campus, two regional campuses in Flint and Dearborn, a Center in Detroit; the university is a founding member of the Association of American Universities. Considered one of the foremost research universities in the United States with annual research expenditures approaching $1.5 billion, Michigan is classified as one of 115 Doctoral Universities with Very High Research by the Carnegie Classification of Institutions of Higher Education. As of October 2018, 50 MacArthur Fellows, 25 Nobel Prize winners, 6 Turing Award winners and 1 Fields Medalist have been affiliated with University of Michigan.
Its comprehensive graduate program offers doctoral degrees in the humanities, social sciences, STEM fields as well as professional degrees in architecture, medicine, pharmacy, social work, public health, dentistry. Michigan's body of living alumni comprises more than 540,000 people, one of the largest alumni bases of any university in the world. Michigan's athletic teams compete in Division I of the NCAA and are collectively known as the Wolverines, they are members of the Big Ten Conference. More than 250 Michigan athletes or coaches have participated in Olympic events, winning more than 150 medals; the University of Michigan was established in Detroit on August 26, 1817 as the Catholepistemiad, or University of Michigania, by the governor and judges of Michigan Territory. Judge Augustus B. Woodward invited The Rev. John Monteith and Father Gabriel Richard, a Catholic priest, to establish the institution. Monteith became its first president and held seven of the professorships, Richard was vice president and held the other six professorships.
Concurrently, Ann Arbor had set aside 40 acres in the hopes of being selected as the state capital. But when Lansing was chosen as the state capital, the city offered the land for a university. What would become the university moved to Ann Arbor in 1837 thanks to Governor Stevens T. Mason; the original 40 acres was the basis of the present Central Campus. This land was once inhabited by the Ojibwe and Bodewadimi Native tribes and was obtained through the Treaty of Fort Meigs. In 1821, the university was renamed the University of Michigan; the first classes in Ann Arbor were held in 1841, with six freshmen and a sophomore, taught by two professors. Eleven students graduated in the first commencement in 1845. By 1866, enrollment had increased to 1,205 students. Women were first admitted in 1870, although Alice Robinson Boise Wood had become the first woman to attend classes in 1866-7. James Burrill Angell, who served as the university's president from 1871 to 1909, aggressively expanded U-M's curriculum to include professional studies in dentistry, engineering and medicine.
U-M became the first American university to use the seminar method of study. Among the early students in the School of Medicine was Jose Celso Barbosa, who in 1880 graduated as valedictorian and the first Puerto Rican to get a university degree in the United States, he returned to Puerto Rico to practice medicine and served in high-ranking posts in the government. From 1900 to 1920, the university constructed many new facilities, including buildings for the dental and pharmacy programs, natural sciences, Hill Auditorium, large hospital and library complexes, two residence halls. In 1920 the university reorganized the College of Engineering and formed an advisory committee of 100 industrialists to guide academic research initiatives; the university became a favored choice for bright Jewish students from New York in the 1920s and 1930s, when the Ivy League schools had quotas restricting the number of Jews to be admitted. Because of its high standards, U-M gained the nickname "Harvard of the West."
During World War II, U-M's research supported military efforts, such as U. S. Navy projects in proximity fuzes, PT boats, radar jamming. After the war, enrollment expanded and by 1950, it reached 21,000, of which more than one third were veterans supported by the G. I. Bill; as the Cold War and the Space Race took hold, U-M received numerous government grants for strategic research and helped to develop peacetime uses for nuclear energy. Much of that work, as well as research into alternative energy sources, is pursued via the Memorial Phoenix Project. In the 1960 Presidential campaign, U. S. Senator John F. Kennedy jokingly referred to himself as "a graduate of the Michigan of the East, Harvard University" in his speech proposing the formation of the Peace Corps speaking to a crowd from the front steps of the Michigan Union. Lyndon B. Johnson gave his speech outlining his Great Society program as the lead speaker during U-M's 1964 spring commencement ceremony. During the 1960s, the university campus was the site of numerous protests against the Vietnam War and university administration.
On March 24, 1965, a group of U-M faculty members and 3,000 students held the nation's first faculty-led "teach-in" to protest against American policy in