History of personal computers in the context of Microcomputer

Microsoft Corporation is an American multinational technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the rise of personal computers through software like Windows, and has since expanded to Internet services, cloud computing, artificial intelligence, video gaming, and other fields. Often described as a Big Tech company, Microsoft is the largest software company by revenue, one of the most valuable public companies, and one of the most valuable brands globally.

Microsoft was founded by Bill Gates and Paul Allen to market 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 Windows. During the 41 years from 1980 to 2021 Microsoft released 9 versions of MS-DOS with a median frequency of 2 years, and 13 versions of Windows with a median frequency of 3 years. The company's 1986 initial public offering (IPO) and subsequent rise in its share price created three billionaires and an estimated 12,000 millionaires among Microsoft employees. Since the 1990s, it has increasingly diversified from the operating system market. Steve Ballmer replaced Gates as CEO in 2000. He oversaw the then-largest of Microsoft's corporate acquisitions in Skype Technologies in 2011, an increased focus on hardware that led to its first in-house PC line, the Surface, in 2012, and the formation of Microsoft Mobile through Nokia. Since Satya Nadella took over as CEO in 2014, the company has changed focus towards cloud computing, as well as its acquisition of LinkedIn for $26.2 billion in 2016. Under Nadella's direction, the company has expanded its video gaming business to support the Xbox brand, establishing the Microsoft Gaming division in 2022 and the acquisition of Activision Blizzard for $68.7 billion in 2023.

An IBM PC compatible is any personal computer that is hardware- and software-compatible with the IBM Personal Computer (IBM PC) and its subsequent models. Like the original IBM PC, an IBM PC–compatible computer uses an x86-based central processing unit, sourced either from Intel or a second source like AMD, Cyrix or other vendors such as Texas Instruments, Fujitsu, OKI, Mitsubishi or NEC and is capable of using interchangeable commodity hardware such as expansion cards. Initially such computers were referred to as PC clones, IBM clones or IBM PC clones, but the term "IBM PC compatible" is now a historical description only, as the vast majority of microcomputers produced since the 1990s are IBM compatible. IBM itself no longer sells personal computers, having sold its division to Lenovo in 2005. "Wintel" is a similar description that is more commonly used for modern computers.

The designation "PC", as used in much of personal computer history, has not meant "personal computer" generally, but rather an x86 computer capable of running the same software that a contemporary IBM or Lenovo PC could. The term was initially in contrast to the variety of home computer systems available in the early 1980s, such as the Apple II, TRS-80, and Commodore 64. Later, the term was primarily used in contrast to Commodore's Amiga and Apple's Macintosh computers.

The ZX Spectrum (UK: /zɛd ɛks/) is an 8-bit home computer developed and marketed by Sinclair Research. The Spectrum played a pivotal role in the history of personal computers and video games, especially in the United Kingdom. It was one of the all-time bestselling British computers with over five million units sold. It was released in the UK on 23 April 1982, the United States in 1983, and Europe in 1984.

The machine was designed by the English entrepreneur and inventor Sir Clive Sinclair and his small team in Cambridge, and was manufactured in Dundee, Scotland by Timex Corporation. It was made to be small, simple, and most importantly inexpensive, with as few components as possible. The addendum "Spectrum" was chosen to highlight the machine's colour display, which differed from the black-and-white display of its predecessor, the ZX81. Rick Dickinson designed its distinctive case, rainbow motif, and rubber keyboard. Video output is transmitted to a television set rather than a dedicated monitor, while application software is loaded and saved onto compact audio cassettes.

A serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. Throughout most of the history of personal computers, data has been transferred through serial ports to devices such as modems, terminals, various peripherals, and directly between computers.

While interfaces such as Ethernet, FireWire, and USB also send data as a serial stream, the term serial port usually denotes hardware compliant with RS-232 or a related standard, such as RS-485 or RS-422.

Gary Arlen Kildall (/ˈkɪldɔːl/; May 19, 1942 – July 11, 1994) was an American computer scientist and microcomputer entrepreneur. During the 1970s, Kildall created the operating system CP/M among other operating systems and programming tools, and subsequently founded Digital Research, Inc. to market and sell his software products. He is considered a pioneer of the personal computer revolution.

In 1974 in Pacific Grove, California, Kildall demonstrated the first working prototype of CP/M, which would later become the dominant operating system for microcomputers for a time. Together with his invention of the BIOS (Basic Input Output System), his operating system allowed a microprocessor-based computer to communicate with disk storage. Kildall was among the earliest individuals to recognize microprocessors as fully capable computers. During the 1980s, Kildall also appeared on PBS as co-host of Computer Chronicles, a weekly informational program that discussed the latest developments in personal computing.

Microsoft Corporation is an American multinational technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the rise of personal computers through software like Windows, and has since expanded to Internet services, cloud computing, artificial intelligence, video gaming, and other fields. Often described as a Big Tech company, Microsoft is the largest software company by revenue, one of the most valuable public companies, and one of the most valuable brands globally.

Founded by Bill Gates and Paul Allen to market BASIC interpreters for the Altair 8800, Microsoft rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Windows. During the 41 years from 1980 to 2021 Microsoft released 9 versions of MS-DOS with a median frequency of 2 years, and 13 versions of Windows with a median frequency of 3 years. The company's 1986 initial public offering (IPO) and subsequent rise in its share price created three billionaires and an estimated 12,000 millionaires among Microsoft employees. Since the 1990s, it has increasingly diversified from the operating system market. Steve Ballmer replaced Gates as CEO in 2000. He oversaw the then-largest of Microsoft's corporate acquisitions in Skype Technologies in 2011, an increased focus on hardware that led to its first in-house PC line, the Surface, in 2012, and the formation of Microsoft Mobile through Nokia. Since Satya Nadella took over as CEO in 2014, the company has changed focus towards cloud computing, as well as its acquisition of LinkedIn for $26.2 billion in 2016. Under Nadella's direction, the company has expanded its video gaming business to support the Xbox brand, establishing the Microsoft Gaming division in 2022 and the acquisition of Activision Blizzard for $68.7 billion in 2023.