Unix is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, development starting in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, others. Intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Microsoft, IBM, Sun Microsystems. In the early 1990s, AT&T sold its rights in Unix to Novell, which sold its Unix business to the Santa Cruz Operation in 1995; the UNIX trademark passed to The Open Group, a neutral industry consortium, which allows the use of the mark for certified operating systems that comply with the Single UNIX Specification. As of 2014, the Unix version with the largest installed base is Apple's macOS. Unix systems are characterized by a modular design, sometimes called the "Unix philosophy"; this concept entails that the operating system provides a set of simple tools that each performs a limited, well-defined function, with a unified filesystem as the main means of communication, a shell scripting and command language to combine the tools to perform complex workflows.
Unix distinguishes itself from its predecessors as the first portable operating system: the entire operating system is written in the C programming language, thus allowing Unix to reach numerous platforms. Unix was meant to be a convenient platform for programmers developing software to be run on it and on other systems, rather than for non-programmers; the system grew larger as the operating system started spreading in academic circles, as users added their own tools to the system and shared them with colleagues. At first, Unix was not designed to be multi-tasking. Unix gained portability, multi-tasking and multi-user capabilities in a time-sharing configuration. Unix systems are characterized by various concepts: the use of plain text for storing data; these concepts are collectively known as the "Unix philosophy". Brian Kernighan and Rob Pike summarize this in The Unix Programming Environment as "the idea that the power of a system comes more from the relationships among programs than from the programs themselves".
In an era when a standard computer consisted of a hard disk for storage and a data terminal for input and output, the Unix file model worked quite well, as I/O was linear. In the 1980s, non-blocking I/O and the set of inter-process communication mechanisms were augmented with Unix domain sockets, shared memory, message queues, semaphores, network sockets were added to support communication with other hosts; as graphical user interfaces developed, the file model proved inadequate to the task of handling asynchronous events such as those generated by a mouse. By the early 1980s, users began seeing Unix as a potential universal operating system, suitable for computers of all sizes; the Unix environment and the client–server program model were essential elements in the development of the Internet and the reshaping of computing as centered in networks rather than in individual computers. Both Unix and the C programming language were developed by AT&T and distributed to government and academic institutions, which led to both being ported to a wider variety of machine families than any other operating system.
Under Unix, the operating system consists of many libraries and utilities along with the master control program, the kernel. The kernel provides services to start and stop programs, handles the file system and other common "low-level" tasks that most programs share, schedules access to avoid conflicts when programs try to access the same resource or device simultaneously. To mediate such access, the kernel has special rights, reflected in the division between user space and kernel space - although in microkernel implementations, like MINIX or Redox, functions such as network protocols may run in user space; the origins of Unix date back to the mid-1960s when the Massachusetts Institute of Technology, Bell Labs, General Electric were developing Multics, a time-sharing operating system for the GE-645 mainframe computer. Multics featured several innovations, but presented severe problems. Frustrated by the size and complexity of Multics, but not by its goals, individual researchers at Bell Labs started withdrawing from the project.
The last to leave were Ken Thompson, Dennis Ritchie, Douglas McIlroy, Joe Ossanna, who decided to reimplement their experiences in a new project of smaller scale. This new operating system was without organizational backing, without a name; the new operating system was a single-tasking system. In 1970, the group coined the name Unics for Uniplexed Information and Computing Service, as a pun on Multics, which stood for Multiplexed Information and Computer Services. Brian Kernighan takes credit for the idea, but adds that "no one can remember" the origin of the final spelling Unix. Dennis Ritchie, Doug McIlroy, Peter G. Neumann credit Kernighan; the operating system was written in assembly language, but in 1973, Version 4 Unix was rewritten in C. Version 4 Unix, still had many PDP-11 dependent codes, is not suitable for porting; the first port to other platform was made five years f
An operating system is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is executed directly by the hardware and makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers; the dominant desktop operating system is Microsoft Windows with a market share of around 82.74%. MacOS by Apple Inc. is in second place, the varieties of Linux are collectively in third place. In the mobile sector, use in 2017 is up to 70% of Google's Android and according to third quarter 2016 data, Android on smartphones is dominant with 87.5 percent and a growth rate 10.3 percent per year, followed by Apple's iOS with 12.1 percent and a per year decrease in market share of 5.2 percent, while other operating systems amount to just 0.3 percent.
Linux distributions are dominant in supercomputing sectors. Other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications. A single-tasking system can only run one program at a time, while a multi-tasking operating system allows more than one program to be running in concurrency; this is achieved by time-sharing, where the available processor time is divided between multiple processes. These processes are each interrupted in time slices by a task-scheduling subsystem of the operating system. Multi-tasking may be characterized in co-operative types. In preemptive multitasking, the operating system slices the CPU time and dedicates a slot to each of the programs. Unix-like operating systems, such as Solaris and Linux—as well as non-Unix-like, such as AmigaOS—support preemptive multitasking. Cooperative multitasking is achieved by relying on each process to provide time to the other processes in a defined manner. 16-bit versions of Microsoft Windows used cooperative multi-tasking.
32-bit versions of both Windows NT and Win9x, used preemptive multi-tasking. Single-user operating systems have no facilities to distinguish users, but may allow multiple programs to run in tandem. A multi-user operating system extends the basic concept of multi-tasking with facilities that identify processes and resources, such as disk space, belonging to multiple users, the system permits multiple users to interact with the system at the same time. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources to multiple users. A distributed operating system manages a group of distinct computers and makes them appear to be a single computer; the development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine; when computers in a group work in cooperation, they form a distributed system.
In an OS, distributed and cloud computing context, templating refers to creating a single virtual machine image as a guest operating system saving it as a tool for multiple running virtual machines. The technique is used both in virtualization and cloud computing management, is common in large server warehouses. Embedded operating systems are designed to be used in embedded computer systems, they are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources, they are compact and efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems. A real-time operating system is an operating system that guarantees to process events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, it uses specialized scheduling algorithms so that a deterministic nature of behavior is achieved. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.
A library operating system is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with the application and configuration code to construct a unikernel: a specialized, single address space, machine image that can be deployed to cloud or embedded environments. Early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions that could automatically run different programs in succession to speed up processing. Operating systems did not exist in their more complex forms until the early 1960s. Hardware features were added, that enabled use of runtime libraries and parallel processing; when personal computers became popular in the 1980s, operating systems were made for them similar in concept to those used on larger computers. In the 1940s, the earliest electronic digital systems had no operating systems.
Electronic systems of this time were programmed on rows of mechanical switches or by jumper wires on plug boards. These were special-purpose systems that, for example, generated ballistics tables for the military or controlled the pri
In electronics, emitter-coupled logic is a high-speed integrated circuit bipolar transistor logic family. ECL uses an overdriven BJT differential amplifier with single-ended input and limited emitter current to avoid the saturated region of operation and its slow turn-off behavior; as the current is steered between two legs of an emitter-coupled pair, ECL is sometimes called current-steering logic,current-mode logic or current-switch emitter-follower logic. In ECL, the transistors are never in saturation, the input/output voltages have a small swing, the input impedance is high and the output impedance is low; as a result, the transistors change states gate delays are low, the fanout capability is high. In addition, the constant current draw of the differential amplifiers minimises delays and glitches due to supply-line inductance and capacitance, the complementary outputs decrease the propagation time of the whole circuit by reducing inverter count. ECL's major disadvantage is that each gate continuously draws current, which means that it requires more power than those of other logic families when quiescent.
The equivalent of emitter-coupled logic made from FETs is called source-coupled logic. A variation of ECL in which all signal paths and gate inputs are differential is known as differential current switch logic. ECL was invented in August 1956 at IBM by Hannon S. Yourke. Called current-steering logic, it was used in the Stretch, IBM 7090, IBM 7094 computers; the logic was called a current-mode circuit. It was used to make the ASLT circuits in the IBM 360/91. Yourke's current switch was a differential amplifier whose input logic levels were different from the output logic levels. "In current mode operation, the output signal consists of voltage levels which vary about a reference level different from the input reference level." In Yourke's design, the two logic reference levels differed by 3 volts. Two complementary versions were used: an NPN version and a PNP version; the NPN output could drive PNP inputs, vice versa. "The disadvantages are that more different power supply voltages are needed, both pnp and npn transistors are required."Instead of alternating NPN and PNP stages, another coupling method employed Zener diodes and resistors to shift the output logic levels to be the same as the input logic levels.
Beginning in the early 1960s, ECL circuits were implemented on monolithic integrated circuits and consisted of a differential-amplifier input stage to perform logic and followed by an emitter-follower stage to drive outputs and shift the output voltages so they will be compatible with the inputs. The emitter-follower output stages could be used to perform wired-or logic. Motorola introduced their first digital monolithic integrated circuit line, MECL I, in 1962. Motorola developed several improved series, with MECL II in 1966, MECL III in 1968 with 1-nanosecond gate propagation time and 300 MHz flip-flop toggle rates, the 10,000 series in 1971; the MECL 10H family was introduced in 1981. Fairchild introduced the F100K family; the ECLinPS family was introduced in 1987. ECLinPS has 1.1 GHz flip-flop toggle frequency. The ECLinPS family parts are available from multiple sources, including Arizona Microtek, National Semiconductor, ON Semiconductor; the high power consumption of ECL meant that it has been used when high speed is a vital requirement.
Older high-end mainframe computers, such as the Enterprise System/9000 members of IBM's ESA/390 computer family, used ECL, as did the Cray-1. From 1975 to 1991 Digital Equipment Corporation's highest performance processors were all based on multi-chip ECL CPUs—from the ECL KL10 through the ECL VAX 8000 and VAX 9000 until the 1991 single-chip CMOS NVAX when the attempt failed to develop a competitive, single-chip ECL processor; the MIPS R6000 computers used ECL. Some of these computer designs used ECL gate arrays. ECL is based on an emitter-coupled pair, shaded red in the figure on the right; the left half of the pair consists of two parallel-connected input transistors T1 and T2 implementing NOR logic. The base voltage of the right transistor T3 is held fixed by a reference voltage source, shaded light green: the voltage divider with a diode thermal compensation and sometimes a buffering emitter follower; as a result, the common emitter resistor RE acts nearly as a current source. The output voltages at the collector load resistors RC1 and RC3 are shifted and buffered to the inverting and non-inverting outputs by the emitter followers T4 and T5.
The output emitter resistors RE4 and RE5 do not exist in all versions of ECL. In some cases 50 Ω line termination resistors connected between the bases of the input transistors and −2 V act as emitter resistors; the ECL circuit operation is considered below with assumption that the input voltage is applied to T1 base, while T2 input is unused or a logical "0" is applied. During the transition, the core of the circuit – the emitter-coupled pair – acts as a differential amplifier with single-ended input; the "long-tail" current source sets the total current flowing through the two legs of the pair. The input voltage controls the current flowing through the transistors by sharing it between the two legs, steering it all to one side when not near the switching point; the gain is higher than at the end s
YouTube is an American video-sharing website headquartered in San Bruno, California. Three former PayPal employees—Chad Hurley, Steve Chen, Jawed Karim—created the service in February 2005. Google bought the site in November 2006 for US$1.65 billion. YouTube allows users to upload, rate, add to playlists, comment on videos, subscribe to other users, it offers a wide variety of corporate media videos. Available content includes video clips, TV show clips, music videos and documentary films, audio recordings, movie trailers, live streams, other content such as video blogging, short original videos, educational videos. Most of the content on YouTube is uploaded by individuals, but media corporations including CBS, the BBC, Hulu offer some of their material via YouTube as part of the YouTube partnership program. Unregistered users can only watch videos on the site, while registered users are permitted to upload an unlimited number of videos and add comments to videos. Videos deemed inappropriate are available only to registered users affirming themselves to be at least 18 years old.
YouTube and its creators earn advertising revenue from Google AdSense, a program which targets ads according to site content and audience. The vast majority of its videos are free to view, but there are exceptions, including subscription-based premium channels, film rentals, as well as YouTube Music and YouTube Premium, subscription services offering premium and ad-free music streaming, ad-free access to all content, including exclusive content commissioned from notable personalities; as of February 2017, there were more than 400 hours of content uploaded to YouTube each minute, one billion hours of content being watched on YouTube every day. As of August 2018, the website is ranked as the second-most popular site in the world, according to Alexa Internet. YouTube has faced criticism over aspects of its operations, including its handling of copyrighted content contained within uploaded videos, its recommendation algorithms perpetuating videos that promote conspiracy theories and falsehoods, hosting videos ostensibly targeting children but containing violent and/or sexually suggestive content involving popular characters, videos of minors attracting pedophilic activities in their comment sections, fluctuating policies on the types of content, eligible to be monetized with advertising.
YouTube was founded by Chad Hurley, Steve Chen, Jawed Karim, who were all early employees of PayPal. Hurley had studied design at Indiana University of Pennsylvania, Chen and Karim studied computer science together at the University of Illinois at Urbana–Champaign. According to a story, repeated in the media and Chen developed the idea for YouTube during the early months of 2005, after they had experienced difficulty sharing videos, shot at a dinner party at Chen's apartment in San Francisco. Karim did not attend the party and denied that it had occurred, but Chen commented that the idea that YouTube was founded after a dinner party "was very strengthened by marketing ideas around creating a story, digestible". Karim said the inspiration for YouTube first came from Janet Jackson's role in the 2004 Super Bowl incident, when her breast was exposed during her performance, from the 2004 Indian Ocean tsunami. Karim could not find video clips of either event online, which led to the idea of a video sharing site.
Hurley and Chen said that the original idea for YouTube was a video version of an online dating service, had been influenced by the website Hot or Not. Difficulty in finding enough dating videos led to a change of plans, with the site's founders deciding to accept uploads of any type of video. YouTube began as a venture capital-funded technology startup from an $11.5 million investment by Sequoia Capital and an $8 million investment from Artis Capital Management between November 2005 and April 2006. YouTube's early headquarters were situated above a pizzeria and Japanese restaurant in San Mateo, California; the domain name www.youtube.com was activated on February 14, 2005, the website was developed over the subsequent months. The first YouTube video, titled Me at the zoo, shows co-founder Jawed Karim at the San Diego Zoo; the video was uploaded on April 23, 2005, can still be viewed on the site. YouTube offered the public a beta test of the site in May 2005; the first video to reach one million views was a Nike advertisement featuring Ronaldinho in November 2005.
Following a $3.5 million investment from Sequoia Capital in November, the site launched on December 15, 2005, by which time the site was receiving 8 million views a day. The site grew and, in July 2006, the company announced that more than 65,000 new videos were being uploaded every day, that the site was receiving 100 million video views per day. According to data published by market research company comScore, YouTube is the dominant provider of online video in the United States, with a market share of around 43% and more than 14 billion views of videos in May 2010. In May 2011, 48 hours of new videos were uploaded to the site every minute, which increased to 60 hours every minute in January 2012, 100 hours every minute in May 2013, 300 hours every minute in November 2014, 400 hours every minute in February 2017; as of January 2012, the site had 800 million unique users a month. It is estimated that in 2007 YouTube consumed as much bandwidth as the entire Internet in 2000. According to third-party web analytics providers and SimilarWeb, YouTube is the second-most visited website in the world, as of December 2016.
The Milwaukee Mile is an one mile-long oval race track in the central United States, located on the grounds of the Wisconsin State Fair Park in West Allis, Wisconsin, a suburb west of Milwaukee. Its grandstand and bleachers seated 37,000 spectators. Paved 65 years ago in 1954, it was a dirt track. In addition to the oval, there was a 1.8 mile road circuit located on the infield. As the oldest operating motor speedway in the world, the Milwaukee Mile’s has hosted at least one auto race every year from 1903 to 2015; the track has held events sanctioned by major bodies, such as the AAA, USAC, NASCAR, CART/Champ Car World Series, the IndyCar Series. There have been many races in regional series such as ARTGO. Famous racers who have competed at the track include: Barney Oldfield, Ralph DePalma, Walt Faulkner, Parnelli Jones, A. J. Foyt, Al Unser, Bobby Unser, Mario Andretti, Bobby Rahal, Jim Clark, Darrell Waltrip, Alan Kulwicki, Emerson Fittipaldi, Bobby Allison, Davey Allison, Nigel Mansell, Rick Mears, Michael Andretti, Alex Zanardi, Harry Gant, Rusty Wallace, Walker Evans, Dario Franchitti and Bernie Eccelstone as well as current racing stars Danica Patrick, Dale Earnhardt, Jr. Jeff Gordon, Tony Kanaan, Scott Dixon, Hélio Castroneves, A. J. Foyt IV, Simona de Silvestro, Colin Braun, Kyle Nicholas, James Davison, Paul Newman, Jay Drake, Nick Bussell, Josh Underwood, Kenny Stevens, a 5 year-old child, Sage Karam and many others.
On December 16, 2009, Wisconsin State Fair Park officials confirmed that the Milwaukee Mile would not host any NASCAR or IndyCar races in 2010. NASCAR confirmed that their June Nationwide Series date would remain in Wisconsin for 2010, as they announced they would hold a race at Road America for the first time since the Grand National Series raced there in 1956. NASCAR announced on January 20, 2010 that the Milwaukee date for the truck series would be moved to August; the track hosted two ASA Late Model Series races in 2010. IndyCar returned to the track in 2011, but the Mile was left off of the preliminary 2012 schedule after a poorly attended 2011 event that resulted in part from an inexperienced promoter. In February 2012, it was announced that IndyCar would return to the Mile on the weekend of June 15–16; the event was promoted by Andretti Sports Marketing, owned by former Indy driver Michael Andretti, was billed as the Milwaukee IndyFest. The event included open-wheel racing featuring the IndyCar Series and the Firestone Indy Lights, as well as a driver question period and autograph sessions and other attractions.
The series again left after the 2015 season and since 2015 the track has hosted no major professional races. The track was a 1 mile private horse racing track by 1876. In 1891, the site was purchased by the Agricultural Society of the State of Wisconsin to create a permanent site for the Wisconsin State Fair; the first motorsports event was held on September 11, 1903. William Jones of Chicago won a five lap speed contest, set the first track record with a 72-second, 50 mph lap. There were 24-hour endurance races in 1907 and 1908. Louis Disbrow won the first 100-mile event in 1915. Barney Oldfield's success at the Mile helped make him a legend, he set the track record in 1905 and raised his speed in 1910 to 70.159 mph in his "Blitzen Benz". In 1911, Ralph DePalma won the first Milwaukee Mile Championship car race, four years before his Indianapolis 500 win. Oldfield drove a gold car built by Harry Miller that enclosed the driver, in June 1917 he beat DePalma in a series of 10 to 25-mile match races.
The July 17, 1933 race was rained out. Wilbur Shaw and the other drivers convinced the track promoters to run the race the following day and the term "rain date" was born. Huge new grandstands were installed with seating for 14,900 people, they replaced the original grandstands that were built in 1914. A roof was placed over the grandstands in 1938; these grandstands stood until new aluminum grandstands were installed in September 2002. The 1939 race was the first AAA Championship race; the 1937 non-championship AAA event was best known for running 96 laps due to a scoring error. It was won by Rex Mays, who continued his domination throughout the 1940s by winning in 1941 and the next race in 1946; the tradition of hosting the "race after the Indianapolis 500" began in 1947. In the 1969 film, starring actor and race driver Paul Newman, the character he plays remarks, “Everybody goes to Milwaukee after Indy.” The Milwaukee Mile held more national championship midget and Indy car races than any other track in the country between 1947 and 1980.
The infield of the quarter-mile dirt infield track at the Mile near the current media center was the location of a football stadium, informally known as the Dairy Bowl. It hosted the NFL's Green Bay Packers from 1934 through 1951, including the NFL championship game in 1939, a 27–0 shutout of the New York Giants on December 10 to secure a fifth league title; the Packers played several games a year in Milwaukee from 1933 through 1994. The team played at Borchert Field in 1933, Marquette Stadium in 1952, moved to County Stadium when it opened in 1953. In 1940 and 1941, the Dairy Bowl served as the home of the Milwaukee Chiefs of the third American Football League; the 50-yard line sat where the start-finish line is located. The city's own entry in the NFL, the Milwaukee Badgers, lasted just five seasons, from 1922 to 1926, played at Athletic Park, renamed Borchert Field in 1928. In 1954 the 1-mile track was paved, and
Reduced instruction set computer
A reduced instruction set computer, or RISC, is one whose instruction set architecture allows it to have fewer cycles per instruction than a complex instruction set computer. Various suggestions have been made regarding a precise definition of RISC, but the general concept is that such a computer has a small set of simple and general instructions, rather than a large set of complex and specialized instructions. Another common RISC trait is their load/store architecture, in which memory is accessed through specific instructions rather than as a part of most instructions. Although a number of computers from the 1960s and'70s have been identified as forerunners of RISCs, the modern concept dates to the 1980s. In particular, two projects at Stanford University and the University of California, Berkeley are most associated with the popularization of this concept. Stanford's MIPS would go on to be commercialized as the successful MIPS architecture, while Berkeley's RISC gave its name to the entire concept and was commercialized as the SPARC.
Another success from this era was IBM's effort that led to the IBM POWER instruction set architecture, PowerPC, Power ISA. As these projects matured, a wide variety of similar designs flourished in the late 1980s and the early 1990s, representing a major force in the Unix workstation market as well as for embedded processors in laser printers and similar products; the many varieties of RISC designs include ARC, Alpha, Am29000, ARM, Atmel AVR, Blackfin, i860, i960, M88000, MIPS, PA-RISC, Power ISA, RISC-V, SuperH, SPARC. In the 21st century, the use of ARM architecture processors in smartphones and tablet computers such as the iPad and Android devices provided a wide user base for RISC-based systems. RISC processors are used in supercomputers such as Summit, which, as of November 2018, is the world's fastest supercomputer as ranked by the TOP500 project. Alan Turing's 1946 Automatic Computing Engine design had many of the characteristics of a RISC architecture. A number of systems, going back to the 1960s, have been credited as the first RISC architecture based on their use of load/store approach.
The term RISC was coined by David Patterson of the Berkeley RISC project, although somewhat similar concepts had appeared before. The CDC 6600 designed by Seymour Cray in 1964 used a load/store architecture with only two addressing modes and 74 operation codes, with the basic clock cycle being 10 times faster than the memory access time. Due to the optimized load/store architecture of the CDC 6600, Jack Dongarra says that it can be considered a forerunner of modern RISC systems, although a number of other technical barriers needed to be overcome for the development of a modern RISC system. Michael J. Flynn views the first RISC system as the IBM 801 design, which began in 1975 by John Cocke and was completed in 1980; the 801 was produced in a single-chip form as the IBM ROMP in 1981, which stood for'Research OPD Micro Processor'. As the name implies, this CPU was designed for "mini" tasks, was used in the IBM RT PC in 1986, which turned out to be a commercial failure, but the 801 inspired several research projects, including new ones at IBM that would lead to the IBM POWER instruction set architecture.
The most public RISC designs, were the results of university research programs run with funding from the DARPA VLSI Program. The VLSI Program unknown today, led to a huge number of advances in chip design and computer graphics; the Berkeley RISC project started in 1980 under the direction of David Patterson and Carlo H. Sequin. Berkeley RISC was based on gaining performance through the use of pipelining and an aggressive use of a technique known as register windowing. In a traditional CPU, one has a small number of registers, a program can use any register at any time. In a CPU with register windows, there are a huge number of registers, e.g. 128, but programs can only use a small number of them, e.g. eight, at any one time. A program that limits itself to eight registers per procedure can make fast procedure calls: The call moves the window "down" by eight, to the set of eight registers used by that procedure, the return moves the window back; the Berkeley RISC project delivered the RISC-I processor in 1982.
Consisting of only 44,420 transistors RISC-I had only 32 instructions, yet outperformed any other single-chip design. They followed this up with the 40,760 transistor, 39 instruction RISC-II in 1983, which ran over three times as fast as RISC-I; the MIPS project grew out of a graduate course by John L. Hennessy at Stanford University in 1981, resulted in a functioning system in 1983, could run simple programs by 1984; the MIPS approach emphasized an aggressive clock cycle and the use of the pipeline, making sure it could be run as "full" as possible. The MIPS system was followed by the MIPS-X and in 1984 Hennessy and his colleagues formed MIPS Computer Systems; the commercial venture resulted in a new architecture, called MIPS and the R2000 microprocessor in 1985. In the early 1980s, significant uncertainties surrounded the RISC concept, it was uncertain if it could have a commercial future, but by the mid-1980s the concepts had matured enough to be seen as commercially viable. In 1986 Hewlett Packard started using an early implementation of their PA-RISC in some of their computers.
In the meantime, the Berkeley RISC effort had become so well known that it became the name for the entire concept and in 1987 Sun Microsystems began shipping systems with the SPARC processor
Professional Developers Conference
Microsoft's Professional Developers Conference was a series of conferences for software developers. In 2011, PDC was merged with Microsoft's web development conference MIX to form the Build Conference. Since 2011, it has been renamed BUILD. July 1992 - Moscone Center in San Francisco, California Known as Win32 Professional Developers Conference First demonstration of the Win32 API and first mention of "Chicago", which would become Windows 95 Estimated attendance of over 5,000 developers Windows NT 3.1 Preliminary Release for Developers was sent to all conference attendees December 1993 - Anaheim Convention Center in Anaheim, CaliforniaWindows "Chicago" Win32 and Object Linking and Embedding version 2 Estimated attendance of over 8,000 Cairo public demonstration, including the Object File System March 1996 - Moscone Center in San Francisco, CaliforniaMicrosoft demonstrated the power of new tools, renamed ActiveX The ActiveX demos were impressive despite occasional technical difficulties. Microsoft and other industry leaders presented an implementation of OLE Scripting.
November, 1996 - Long Beach, California November 3–7, 1996 September 1997 - San Diego Convention Center in San Diego, CaliforniaFirst demonstrations of Windows NT 5.0, release of Beta 1 to developers Estimated attendance of 6,200 October 11–15, 1998 - Colorado Convention Center, ColoradoWindows NT 5.0, the release of Beta 2 to developers. Windows DNA technology announced, including COM+ July 11–14, 2000 - Orange County Convention Center in Orlando, Florida. NET Framework and Visual Studio. NET announced, initial beta release given to attendees C# programming language announced and demonstrated ASP+, the successor to Active Server Pages was announced. NET in the year Announcement of the end of the Windows 9x line, culminating with a planned 2002 release of a new operating system, "Whistler" Internet Explorer 5.5 was released Estimated attendance of 6,000 developers October 22–26, 2001 - Los Angeles Convention Center in Los Angeles, CaliforniaRelease candidates of the. NET Framework and Visual Studio.
NET were announced during Bill Gates' keynote. Windows XP was released. Introduction of Tablet PC, including a software development kit.. NET My Services announced.. NET Compact Framework introduced. First discussions of Internet Information Services version 6; the Counting Crows performed at the PDC party at the Staples Center. October 27–30, 2003 - Los Angeles Convention Center in Los Angeles, California Windows Longhorn revealed - Avalon, Indigo, WinFS September 13–16, 2005 - Los Angeles Convention Center in Los Angeles, California Windows Vista build 5219 handed out to attendees Internet Explorer 7 demoed Office 12 demoed with ribbon bar. NET 2.0 October 27–30, 2008 - Los Angeles Convention Center in Los Angeles, California. First demonstration of Windows 7 as well as Office 14 for the Web. Introduction of Windows Azure, Microsoft's data center hosting platform. Outlook to. NET 4.0, Visual Studio 2010 and a new. NET Application Server. Release of Microsoft Surface SDK and first demonstration of SecondLight, a next generation Surface prototype.
November 17–20, 2009 - Los Angeles Convention Center in Los Angeles, CaliforniaVision of Three Screens and a Cloud Emergence of Windows Azure with billed, commercial service to begin in February 2010. Many back-end announcements: Microsoft AppFabric, based on the earlier. NET Application Server and the caching technology. Microsoft SQL Server Modeling Services released BizTalk Server 2009 R2 announced with new features like an improved mapper for early 2010 release Many front-end announcements: Release of first public betas for Microsoft Office 2010, Microsoft Silverlight 4 Early revelations about Microsoft Internet Explorer 9 and its objective of better Acid3 performance and HTML5/CSS3 compliance. A special "PDC 2009" Acer 1420p Multi-touch Tablet PC was given out to all attendees October 28–29, 2010 - Microsoft Campus in Redmond, WashingtonAnnounced new Platform Features for Cloud Computing VmRoles announced to port existing on-premises Applications to the Cloud Microsoft "Dallas" renamed to Windows Azure Marketplace DataMarket Windows Azure Marketplace Applications announced An unlocked Windows Phone 7 smartphone was given out to all attendees Microsoft limited the number of attendees to 1,000 Many public viewing events all over the globe Dev Connections Microsoft TechEd Mix PASS SQLBits VSLive!
Windows Hardware Engineering Conference Professional Developers Conference Video Archive Of Keynotes Build Windows