Lotus 1-2-3 is a discontinued spreadsheet program from Lotus Software. It was the IBM PC's first killer application, was hugely popular in the 1980s and contributed to the success of the IBM PC; the first spreadsheet, VisiCalc, had helped launch the Apple II as one of the earliest personal computers in business use. With IBM's entry into the market, VisiCalc was slow to respond, when they did, they launched what was a straight port of their existing system in spite of the expanded hardware capabilities. Lotus' solution was marketed as a three-in-one integrated solution, which handled spreadsheet calculations, database functionality, graphical charts, hence the name "1-2-3", though how much database capability was debatable given Lotus' sparse memory. 1-2-3 overtook VisiCalc, as well as Multiplan and SuperCalc, two VisiCalc competitors. 1-2-3 was the spreadsheet standard throughout the 1980s and into the 1990s, part of an unofficial set of three stand-alone office automation products that included dBase and WordPerfect, to build a complete business platform.
With the acceptance of Windows 3.0, the market for desktop software grew more. None of the major spreadsheet developers had considered the graphical user interface to supplement their DOS offerings, so they responded to Microsoft's own graphical-based products and Word. Lotus was never recovered. IBM purchased Lotus in 1995 and continued to sell Lotus offerings, only ending sales in 2013. VisiCalc was launched in 1979 on the Apple II and became a best-seller. Compared to earlier programs, VisiCalc allowed one to construct free-form calculation systems for any purpose, the limitations being memory and speed related; the application was so compelling that there were numerous stories of people buying Apple II machines to run the program. VisiCalc's runaway success on the Apple led to direct bug compatible ports to other platforms, including the Atari 8-bit family, Commodore PET and many others; this included the IBM PC when it launched in 1981, where it became another best-seller, with an estimated 300,000 sales in the first six months on the market.
There were well known problems with VisiCalc, several competitors appeared to address some of these issues. One early example was 1980's SuperCalc, which solved the problem of circular references, while a later example was Microsoft Multiplan from 1981, which offered larger sheets and other improvements. In spite of these, others, VisiCalc continued to outsell them all; the Lotus Development Corporation was founded by Mitchell Kapor, a friend of the developers of VisiCalc. 1-2-3 was written by Jonathan Sachs, who had written two spreadsheet programs while working at Concentric Data Systems, Inc. To aid its growth, in the UK, elsewhere, Lotus 1-2-3 was the first computer software to use television consumer advertising. Lotus 1-2-3 was released on 26 January 1983, overtook Visicalc in sales. Unlike Microsoft Multiplan, it stayed close to the model of VisiCalc, including the "A1" letter and number cell notation, slash-menu structure, it was cleanly programmed and bug-free, gained speed from being written in x86 assembly language and wrote directly to video memory rather than use the slow DOS and/or BIOS text output functions.
Among other novelties that Lotus introduced was a graph maker that could display several forms of graphs but required the user to have a graphics card. At this early stage, the only video boards available for the PC were IBM's Color/Graphics Adapter and Monochrome Display and Printer Adapter while the latter did not support any graphics. However, because the two video boards used different RAM and port addresses, both could be installed in the same machine and so Lotus took advantage of this by supporting a "split" screen mode whereby the user could display the worksheet portion of 1-2-3 on the sharper monochrome video and the graphics on the CGA display; the initial release of 1-2-3 supported CGA, MDA or dual monitor mode. However, a few months support was added for Hercules Computer Technology's Hercules Graphics Adapter, a clone of the MDA that allowed bitmap mode; the ability to have high-resolution text and graphics capabilities proved popular and Lotus 1-2-3 is credited with popularizing the Hercules graphics card.
Subsequent releases of Lotus 1-2-3 supported more video standards as time went on, including EGA, AT&T/Olivetti, VGA. Support for the PCjr/Tandy modes was never added and users of those machines were limited to CGA graphics; the early versions of 1-2-3 had a key disk copy protection. While the program was hard disk installable, the user had to insert the original floppy disk when starting 1-2-3 up; this protection scheme was cracked and a minor inconvenience for home users, but proved a serious nuisance in an office setting. Starting with Release 3.0, Lotus no longer used copy protection. However, it was necessary to "initialize" the System disk with one's name and company name so as to customize his copy of the program. Release 2.2 and higher had this requirement. This was an irreversible process unless one had made an exact copy of the original disk so as to be able to change names if he transferred the program to someone else; the reliance on the specific hardware of the IBM PC led to 1-2-3 being utilized as one of the two stress test applications, along w
The Macintosh is a family of personal computers designed and sold by Apple Inc. since January 1984. The original Macintosh was the first mass-market personal computer that featured a graphical user interface, built-in screen and mouse. Apple sold the Macintosh alongside its popular Apple II family of computers for ten years before they were discontinued in 1993. Early Macintosh models were expensive, hindering its competitiveness in a market dominated by the Commodore 64 for consumers, as well as the IBM Personal Computer and its accompanying clone market for businesses. Macintosh systems still found success in education and desktop publishing and kept Apple as the second-largest PC manufacturer for the next decade. In the early 1990s, Apple introduced models such as the Macintosh LC II and Color Classic which were price-competitive with Wintel machines at the time. However, the introduction of Windows 3.1 and Intel's Pentium processor which beat the Motorola 68040 in most benchmarks took market share from Apple, by the end of 1994 Apple was relegated to third place as Compaq became the top PC manufacturer.
After the transition to the superior PowerPC-based Power Macintosh line in the mid-1990s, the falling prices of commodity PC components, poor inventory management with the Macintosh Performa, the release of Windows 95 saw the Macintosh user base decline. Prompted by the returning Steve Jobs' belief that the Macintosh line had become too complex, Apple consolidated nearly twenty models in mid-1997 down to four in mid-1999: The Power Macintosh G3, iMac, 14.1" PowerBook G3, 12" iBook. All four products were critically and commercially successful due to their high performance, competitive prices and aesthetic designs, helped return Apple to profitability. Around this time, Apple phased out the Macintosh name in favor of "Mac", a nickname, in common use since the development of the first model. Since their transition to Intel processors in 2006, the complete lineup is based on said processors and associated systems, its current lineup includes four desktops, three laptops. Its Xserve server was discontinued in 2011 in favor of the Mac Mac Pro.
Apple has developed a series of Macintosh operating systems. The first versions had no name but came to be known as the "Macintosh System Software" in 1988, "Mac OS" in 1997 with the release of Mac OS 7.6, retrospectively called "Classic Mac OS". In 2001, Apple released Mac OS X, a modern Unix-based operating system, rebranded to OS X in 2012, macOS in 2016; the current version is macOS Mojave, released on September 24, 2018. Intel-based Macs are capable of running non-Apple operating systems such as Linux, OpenBSD, Microsoft Windows with the aid of Boot Camp or third-party software. Apple produced a Unix-based operating system for the Macintosh called A/UX from 1988 to 1995, which resembled contemporary versions of the Macintosh system software. Apple does not license macOS for use on non-Apple computers, however System 7 was licensed to various companies through Apple's Macintosh clone program from 1995 to 1997. Only one company, UMAX Technologies was licensed to ship clones running Mac OS 8.
Since Apple's transition to Intel processors, there is a sizeable community around the world that specialises in hacking macOS to run on non-Apple computers, which are called "Hackintoshes". The Macintosh project began in 1979 when Jef Raskin, an Apple employee, envisioned an easy-to-use, low-cost computer for the average consumer, he wanted to name the computer after his favorite type of apple, the McIntosh, but the spelling was changed to "Macintosh" for legal reasons as the original was the same spelling as that used by McIntosh Laboratory, Inc. the audio equipment manufacturer. Steve Jobs requested that McIntosh Laboratory give Apple a release for the newly spelled name, thus allowing Apple to use it; the request was denied, forcing Apple to buy the rights to use this name. In 1978, Apple began to organize the Apple Lisa project, aiming to build a next-generation machine similar to an advanced Apple II or the yet-to-be-introduced IBM PC. In 1979, Steve Jobs learned of the advanced work on graphical user interfaces taking place at Xerox PARC.
He arranged for Apple engineers to be allowed to visit PARC to see the systems in action. The Apple Lisa project was redirected to utilize a GUI, which at that time was well beyond the state of the art for microprocessor capabilities. Things had changed with the introduction of the 32-bit Motorola 68000 in 1979, which offered at least an order of magnitude better performance than existing designs, made a software GUI machine a practical possibility; the basic layout of the Lisa was complete by 1982, at which point Jobs's continual suggestions for improvements led to him being kicked off the project. At the same time that the Lisa was becoming a GUI machine in 1979, Jef Raskin started the Macintosh project; the design at that time was for a easy-to-use machine for the average consumer. In
Byte was an American microcomputer magazine, influential in the late 1970s and throughout the 1980s because of its wide-ranging editorial coverage. Whereas many magazines were dedicated to specific systems or the home or business users' perspective, Byte covered developments in the entire field of "small computers and software," and sometimes other computing fields such as supercomputers and high-reliability computing. Coverage was in-depth with much technical detail, rather than user-oriented. Byte started in 1975, shortly after the first personal computers appeared as kits advertised in the back of electronics magazines. Byte was published monthly, with an initial yearly subscription price of $10. Print publication ceased in 1998 and online publication in 2013. In 1975 Wayne Green was the editor and publisher of 73 and his ex-wife, Virginia Londner Green was the Business Manager of 73 Inc. In the August 1975 issue of 73 magazine Wayne's editorial column started with this item: The response to computer-type articles in 73 has been so enthusiastic that we here in Peterborough got carried away.
On May 25th we made a deal with the publisher of a small computer hobby magazine to take over as editor of a new publication which would start in August... Byte. Carl Helmers published a series of six articles in 1974 that detailed the design and construction of his "Experimenter's Computer System", a personal computer based on the Intel 8008 microprocessor. In January 1975 this became the monthly ECS magazine with 400 subscribers; the last issue was published on May 12, 1975 and in June the subscribers were mailed a notice announcing Byte magazine. Carl wrote to another hobbyist newsletter, Micro-8 Computer User Group Newsletter, described his new job as editor of Byte magazine. I got a note in the mail about two weeks ago from Wayne Green, publisher of'73 Magazine' saying hello and why don't you come up and talk a bit; the net result of a follow up is the decision to create BYTE magazine using the facilities of Green Publishing Inc. I will end up with the editorial focus for the magazine. Virginia Londner Green had returned to 73 in the December 1974 issue and incorporated Green Publishing in March 1975.
The first five issues of Byte were published by Green Publishing and the name was changed to Byte Publications starting with the February 1976 issue. Carl Helmers was a co-owner of Byte Publications; the first four issues were produced in the offices of 73 and Wayne Green was listed as the publisher. One day in November 1975 Wayne came to work and found that the Byte magazine staff had moved out and taken the January issue with them; the February 1976 issue of Byte has a short story about the move. "After a start which reads like a romantic light opera with an episode or two reminiscent of the Keystone Cops, Byte magazine has moved into separate offices of its own." Wayne Green was not happy about losing Byte magazine so he was going to start a new one called Kilobyte. Byte trademarked KILOBYTE as a cartoon series in Byte magazine; the new magazine was called Kilobaud. There was competition and animosity between Byte Publications and 73 Inc. but both remained in the small town of Peterborough, New Hampshire.
Articles in the first issue included Which Microprocessor For You? by Hal Chamberlin, Write Your Own Assembler by Dan Fylstra and Serial Interface by Don Lancaster. Advertisements from Godbout, MITS, Processor Technology, SCELBI, Sphere appear, among others. Early articles in Byte were do-it-yourself electronic or software projects to improve small computers. A continuing feature was Ciarcia's Circuit Cellar, a column in which electronic engineer Steve Ciarcia described small projects to modify or attach to a computer. Significant articles in this period included the "Kansas City" standard for data storage on audio tape, insertion of disk drives into S-100 computers, publication of source code for various computer languages, coverage of the first microcomputer operating system, CP/M. Byte ran Microsoft's first advertisement, as "Micro-Soft", to sell a BASIC interpreter for 8080-based computers. In spring of 1979, owner/publisher Virginia Williamson sold Byte to McGraw-Hill, she became a vice president of McGraw-Hill Publications Company.
Shortly after the IBM PC was introduced, in 1981, the magazine changed editorial policies. It de-emphasized the do-it-yourself electronics and software articles, began running product reviews, it continued its wide-ranging coverage of hardware and software, but now it reported "what it does" and "how it works", not "how to do it". The editorial focus remained on home and personal computers). By the early 1980s Byte had become an "elite" magazine, seen as a peer of Rolling Stone and Playboy, others such as David Bunnell of PC Magazine aspired to emulate its reputation and success, it was the only computer publication on the 1981 Folio 400 list of largest magazines. Byte's 1982 average number of pages was 543, the number of paid advertising pages grew by more than 1,000 while most magazines' amount of advertising did not change, its circulation of 420,000 was the third highest of all computer magazines. Byte earned $9 million from revenue of $36.6 million in 1983, twice the average profit margin for the magazine industry.
It remained successful while many other magazines failed in 1984 during economic weakness in the computer industry. The October 1984 issue had about 300 pages of ads sold at an average of $6,000 per page. From 1975 to 1986 Byte covers featured the artwork of Robert Tinney. Thes
The TRS-80 Micro Computer System is a desktop microcomputer launched in 1977 and sold by Tandy Corporation through their RadioShack stores. The name is an abbreviation of Z-80 microprocessor, it is one of mass-marketed retail home computers. The TRS-80 has a full-stroke QWERTY keyboard, the Zilog Z80 processor, 4 KB DRAM standard memory, small size and desk footprint, floating-point BASIC programming language, standard 64-character/line video monitor, a starting price of US$600. An extensive line of upgrades and add-on hardware peripherals for the TRS-80 was developed and marketed by Tandy/RadioShack; the basic system can be expanded with up to 48 KB of RAM, up to four floppy disk drives and/or hard disk drives. Tandy/RadioShack provided full-service support including upgrade and training services in their thousands of stores worldwide. By 1979, the TRS-80 had the largest selection of software in the microcomputer market; until 1982, the TRS-80 was the best-selling PC line, outselling the Apple II series by a factor of five according to one analysis.
In mid-1980, the broadly compatible TRS-80 Model III was released. The Model I was discontinued shortly thereafter due to stricter FCC regulations on radio-frequency interference to nearby electronic devices. In April 1983 the Model III was succeeded by the compatible Model 4. Following the original Model I and its compatible descendants, the TRS-80 name became a generic brand used on other technically unrelated computer lines sold by Tandy, including the TRS-80 Model II, TRS-80 Model 2000, TRS-80 Model 100, TRS-80 Color Computer and TRS-80 Pocket Computer. In the mid-1970s, Tandy Corporation's RadioShack division was a successful American chain of more than 3,000 electronics stores. After buyer Don French purchased a MITS Altair kit computer, he began designing his own and showed it to vice president of manufacturing John Roach. Although the design did not impress Roach, the idea of selling a microcomputer did; when the two men visited National Semiconductor in California in mid-1976, Steve Leininger's expertise on the SC/MP microprocessor impressed them.
National executives refused to provide Leininger's contact information when French and Roach wanted to hire him as a consultant, but they found Leininger working part-time at Byte Shop and he and French began working together in June 1976. The company envisioned a kit, but Leininger persuaded the others that because "too many people can't solder", a preassembled computer would be better. Tandy had 11 million customers that might buy a microcomputer, but it would be much more expensive than the US$30 median price of a RadioShack product, a great risk for the conservative company. Executives feared losing money as Sears did with Cartrivision, many opposed the project; as the popularity of CB radio—at one point comprising more than 20% of RadioShack's sales—declined, the company sought new products. In December 1976 French and Leininger received official approval for the project but were told to emphasize cost savings. In February 1977 they showed their prototype, running a simple tax-accounting program, to Charles Tandy, head of Tandy Corporation.
The program crashed as the computer could not handle the US$150,000 figure that Tandy typed in as his salary, the two men added support for floating-point math to its Tiny BASIC to prevent a recurrence. After the demonstration Tandy revealed that he had leaked the computer's existence to the press, so the project was approved. MITS sold 1,000 Altairs in February 1975, was selling 10,000 a year. Leininger and French suggested that RadioShack could sell 50,000 computers, but others disagreed and suggested 1,000 to 3,000 per year at the target US$199 price. Roach persuaded Tandy to agree to build 3,500—the number of RadioShack stores—so that each store could use a computer for inventory purposes if they did not sell. Having spent less than US$150,000 on development, RadioShack announced the TRS-80 at a New York City press conference on August 3, 1977, it cost a RadioShack tape recorder as datacassette storage. The company hoped that the new computer would help RadioShack sell higher-priced products, improve its "schlocky" image among customers.
Small businesses were the primary target market, followed by educators consumers and hobbyists. Although the press conference did not receive much media attention because of a terrorist bombing elsewhere in the city, the computer received much more publicity at the Personal Computer Faire in Boston two days later. A front-page Associated Press article discussed the novelty of a large consumer-electronics company selling a home computer that could "do a payroll for up to 15 people in a small business, teach children mathematics, store your favorite recipes or keep track of an investment portfolio, it can play cards." Six sacks of mail arrived at Tandy headquarters asking about the computer, over 15,000 people called to purchase a TRS-80—paralyzing the company switchboard—and 250,000 joined the waiting list with a $100 deposit. Despite the internal skepticism, RadioShack aggressively entered the
William Henry Gates III is an American business magnate, author and humanitarian. He is best known as the principal founder of Microsoft Corporation. During his career at Microsoft, Gates held the positions of chairman, CEO and chief software architect, while being the largest individual shareholder until May 2014. In 1975, Gates and Paul Allen launched Microsoft, which became the world's largest PC software company. Gates led the company as chief executive officer until stepping down in January 2000, but he remained as chairman and created the position of chief software architect for himself. In June 2006, Gates announced that he would be transitioning from full-time work at Microsoft to part-time work and full-time work at the Bill & Melinda Gates Foundation, the private charitable foundation that he and his wife, Melinda Gates, established in 2000, he transferred his duties to Ray Ozzie and Craig Mundie. He stepped down as chairman of Microsoft in February 2014 and assumed a new post as technology adviser to support the newly appointed CEO Satya Nadella.
Gates is one of the best-known entrepreneurs of the personal computer revolution. He has been criticized for his business tactics; this opinion has been upheld by numerous court rulings. Since 1987, Gates has been included in the Forbes list of the world's wealthiest people, an index of the wealthiest documented individuals and ranking against those with wealth, not able to be ascertained. From 1995 to 2017, he held the Forbes title of the richest person in the world all but four of those years, held it from March 2014 to July 2017, with an estimated net worth of US$89.9 billion as of October 2017. However, on July 27, 2017, since October 27, 2017, he has been surpassed by Amazon founder and CEO Jeff Bezos, who had an estimated net worth of US$90.6 billion at the time. As of August 6, 2018, Gates had a net worth of $95.4 billion, making him the second-richest person in the world, behind Bezos. In his career and since leaving Microsoft, Gates pursued a number of philanthropic endeavors, he donated large amounts of money to various charitable organizations and scientific research programs through the Bill & Melinda Gates Foundation, reported to be the world's largest private charity.
In 2009, Gates and Warren Buffett founded The Giving Pledge, whereby they and other billionaires pledge to give at least half of their wealth to philanthropy. The foundation works to save lives and improve global health, is working with Rotary International to eliminate polio. Gates was born in Seattle, Washington, on October 28, 1955, he is the son of Mary Maxwell Gates. His ancestry includes English, German and Scots-Irish, his father was a prominent lawyer, his mother served on the board of directors for First Interstate BancSystem and the United Way. Gates' maternal grandfather was J. W. Maxwell, a national bank president. Gates has one older sister, a younger sister, Libby, he is the fourth of his name in his family, but is known as William Gates III or "Trey" because his father had the "II" suffix. The family lived in the Sand Point area of Seattle in a home, once damaged by a rare tornado when Gates was seven years old. Early on in his life, Gates observed; when Gates was young, his family attended a church of the Congregational Christian Churches, a Protestant Reformed denomination.
The family encouraged competition. There was always a reward for winning and there was always a penalty for losing". At 13, he enrolled in the Lakeside School, a private preparatory school and wrote his first software program; when Gates was in the eighth grade, the Mothers' Club at the school used proceeds from Lakeside School's rummage sale to buy a Teletype Model 33 ASR terminal and a block of computer time on a General Electric computer for the school's students. Gates took an interest in programming the GE system in BASIC, was excused from math classes to pursue his interest, he wrote his first computer program on this machine: an implementation of tic-tac-toe that allowed users to play games against the computer. Gates was fascinated by the machine; when he reflected back on that moment, he said, "There was just something neat about the machine." After the Mothers Club donation was exhausted, he and other students sought time on systems including DEC PDP minicomputers. One of these systems was a PDP-10 belonging to Computer Center Corporation, which banned four Lakeside students – Gates, Paul Allen, Ric Weiland, Kent Evans – for the summer after it caught them exploiting bugs in the operating system to obtain free computer time.
At the end of the ban, the four students offered to find bugs in CCC's software in exchange for extra computer time. Rather than use the system via Teletype, Gates went to CCC's offices and studied source code for various programs that ran on the system, including programs in Fortran and machine language; the arrangement with CCC continued until 1970. The following year, Information Sciences, Inc. hired the four Lakeside students to write a payroll program in COBOL, providing them computer time and royalties. After his administrators became aware of his programming abilities, Gates wrote the school's student information system software to schedule students in classes, he modified the code so that he was placed in classes with "a disproportionate number of interesting girls." He stated that "it
Microsoft Corporation is an American multinational technology company with headquarters in Redmond, Washington. It develops, licenses and sells computer software, consumer electronics, personal computers, related services, its best known software products are the Microsoft Windows line of operating systems, the Microsoft Office suite, the Internet Explorer and Edge web browsers. Its flagship hardware products are the Xbox video game consoles and the Microsoft Surface lineup of touchscreen personal computers; as of 2016, it is the world's largest software maker by revenue, one of the world's most valuable companies. The word "Microsoft" is a portmanteau of "microcomputer" and "software". Microsoft is ranked No. 30 in the 2018 Fortune 500 rankings of the largest United States corporations by total revenue. Microsoft was founded by Bill Gates and Paul Allen on April 4, 1975, to develop and sell BASIC interpreters for the Altair 8800, it rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Microsoft Windows.
The company's 1986 initial public offering, subsequent rise in its share price, created three billionaires and an estimated 12,000 millionaires among Microsoft employees. Since the 1990s, it has diversified from the operating system market and has made a number of corporate acquisitions, their largest being the acquisition of LinkedIn for $26.2 billion in December 2016, followed by their acquisition of Skype Technologies for $8.5 billion in May 2011. As of 2015, Microsoft is market-dominant in the IBM PC-compatible operating system market and the office software suite market, although it has lost the majority of the overall operating system market to Android; the company produces a wide range of other consumer and enterprise software for desktops and servers, including Internet search, the digital services market, mixed reality, cloud computing and software development. Steve Ballmer replaced Gates as CEO in 2000, envisioned a "devices and services" strategy; this began with the acquisition of Danger Inc. in 2008, entering the personal computer production market for the first time in June 2012 with the launch of the Microsoft Surface line of tablet computers.
Since Satya Nadella took over as CEO in 2014, the company has scaled back on hardware and has instead focused on cloud computing, a move that helped the company's shares reach its highest value since December 1999. In 2018, Microsoft surpassed Apple as the most valuable publicly traded company in the world after being dethroned by the tech giant in 2010. Childhood friends Bill Gates and Paul Allen sought to make a business utilizing their shared skills in computer programming. In 1972 they founded their first company, named Traf-O-Data, which sold a rudimentary computer to track and analyze automobile traffic data. While Gates enrolled at Harvard, Allen pursued a degree in computer science at Washington State University, though he dropped out of school to work at Honeywell; the January 1975 issue of Popular Electronics featured Micro Instrumentation and Telemetry Systems's Altair 8800 microcomputer, which inspired Allen to suggest that they could program a BASIC interpreter for the device. After a call from Gates claiming to have a working interpreter, MITS requested a demonstration.
Since they didn't yet have one, Allen worked on a simulator for the Altair while Gates developed the interpreter. Although they developed the interpreter on a simulator and not the actual device, it worked flawlessly when they demonstrated the interpreter to MITS in Albuquerque, New Mexico. MITS agreed to distribute it, marketing it as Altair BASIC. Gates and Allen established Microsoft on April 4, 1975, with Gates as the CEO; the original name of "Micro-Soft" was suggested by Allen. In August 1977 the company formed an agreement with ASCII Magazine in Japan, resulting in its first international office, "ASCII Microsoft". Microsoft moved to a new home in Bellevue, Washington in January 1979. Microsoft entered the operating system business in 1980 with its own version of Unix, called Xenix. However, it was MS-DOS. After negotiations with Digital Research failed, IBM awarded a contract to Microsoft in November 1980 to provide a version of the CP/M OS, set to be used in the upcoming IBM Personal Computer.
For this deal, Microsoft purchased a CP/M clone called 86-DOS from Seattle Computer Products, which it branded as MS-DOS, though IBM rebranded it to PC DOS. Following the release of the IBM PC in August 1981, Microsoft retained ownership of MS-DOS. Since IBM had copyrighted the IBM PC BIOS, other companies had to reverse engineer it in order for non-IBM hardware to run as IBM PC compatibles, but no such restriction applied to the operating systems. Due to various factors, such as MS-DOS's available software selection, Microsoft became the leading PC operating systems vendor; the company expanded into new markets with the release of the Microsoft Mouse in 1983, as well as with a publishing division named Microsoft Press. Paul Allen resigned from Microsoft in 1983 after developing Hodgkin's disease. Allen claimed that Gates wanted to dilute his share in the company when he was diagnosed with Hodgkin's disease because he didn't think he was working hard enough. After leaving Microsoft, Allen lost billions of dollars on ill-conceived or mistimed technology investments.
He invested in low-tech sectors, sports teams, commercial real estate. Despite having begun jointly developing a new operating system, OS/2, with IBM in
A computer is a device that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming. Modern computers have the ability to follow generalized sets of called programs; these programs enable computers to perform an wide range of tasks. A "complete" computer including the hardware, the operating system, peripheral equipment required and used for "full" operation can be referred to as a computer system; this term may as well be used for a group of computers that are connected and work together, in particular a computer network or computer cluster. Computers are used as control systems for a wide variety of industrial and consumer devices; this includes simple special purpose devices like microwave ovens and remote controls, factory devices such as industrial robots and computer-aided design, general purpose devices like personal computers and mobile devices such as smartphones. The Internet is run on computers and it connects hundreds of millions of other computers and their users.
Early computers were only conceived as calculating devices. Since ancient times, simple manual devices like the abacus aided people in doing calculations. Early in the Industrial Revolution, some mechanical devices were built to automate long tedious tasks, such as guiding patterns for looms. More sophisticated electrical machines did specialized analog calculations in the early 20th century; the first digital electronic calculating machines were developed during World War II. The speed and versatility of computers have been increasing ever since then. Conventionally, a modern computer consists of at least one processing element a central processing unit, some form of memory; the processing element carries out arithmetic and logical operations, a sequencing and control unit can change the order of operations in response to stored information. Peripheral devices include input devices, output devices, input/output devices that perform both functions. Peripheral devices allow information to be retrieved from an external source and they enable the result of operations to be saved and retrieved.
According to the Oxford English Dictionary, the first known use of the word "computer" was in 1613 in a book called The Yong Mans Gleanings by English writer Richard Braithwait: "I haue read the truest computer of Times, the best Arithmetician that euer breathed, he reduceth thy dayes into a short number." This usage of the term referred to a human computer, a person who carried out calculations or computations. The word continued with the same meaning until the middle of the 20th century. During the latter part of this period women were hired as computers because they could be paid less than their male counterparts. By 1943, most human computers were women. From the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations; the Online Etymology Dictionary gives the first attested use of "computer" in the 1640s, meaning "one who calculates". The Online Etymology Dictionary states that the use of the term to mean "'calculating machine' is from 1897."
The Online Etymology Dictionary indicates that the "modern use" of the term, to mean "programmable digital electronic computer" dates from "1945 under this name. Devices have been used to aid computation for thousands of years using one-to-one correspondence with fingers; the earliest counting device was a form of tally stick. Record keeping aids throughout the Fertile Crescent included calculi which represented counts of items livestock or grains, sealed in hollow unbaked clay containers; the use of counting rods is one example. The abacus was used for arithmetic tasks; the Roman abacus was developed from devices used in Babylonia as early as 2400 BC. Since many other forms of reckoning boards or tables have been invented. In a medieval European counting house, a checkered cloth would be placed on a table, markers moved around on it according to certain rules, as an aid to calculating sums of money; the Antikythera mechanism is believed to be the earliest mechanical analog "computer", according to Derek J. de Solla Price.
It was designed to calculate astronomical positions. It was discovered in 1901 in the Antikythera wreck off the Greek island of Antikythera, between Kythera and Crete, has been dated to c. 100 BC. Devices of a level of complexity comparable to that of the Antikythera mechanism would not reappear until a thousand years later. Many mechanical aids to calculation and measurement were constructed for astronomical and navigation use; the planisphere was a star chart invented by Abū Rayhān al-Bīrūnī in the early 11th century. The astrolabe was invented in the Hellenistic world in either the 1st or 2nd centuries BC and is attributed to Hipparchus. A combination of the planisphere and dioptra, the astrolabe was an analog computer capable of working out several different kinds of problems in spherical astronomy. An astrolabe incorporating a mechanical calendar computer and gear-wheels was invented by Abi Bakr of Isfahan, Persia in 1235. Abū Rayhān al-Bīrūnī invented the first mechanical geared lunisolar calendar astrolabe, an early fixed-wired knowledge processing machine with a gear train and gear-wheels, c. 1000 AD.
The sector, a calculating instrument used for solving problems in proportion, trigonometry and division, for various functions, such as squares and cube roots, was developed in