Personal computer facts for kids
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A personal computer (PC) is the common name for a type of computer that is most popular in offices and homes. The first PC called the "IBM PC" was made by the company called IBM in 1981, although many computers were made before like the Commodore PET. Smartphones and tablet computers are also computers for personal use, but they are not often called "personal computers".
Today, most PCs usually have a basic set of software called an operating system. The operating system is responsible for several tasks including providing an user interface (UI). The most popular operating system on PCs is Windows, sold by Microsoft Corporation. PCs made by a company called Apple Inc. can use a different system of software called Mac OS that is sold by Apple Inc.
Many free operating systems are available. They are called Linux operating systems. There are over 300 different Linux "distributions". Each one has a different purpose. Ubuntu-Linux is the most-used Linux because it is the easiest to use.
A modern PC has a minimum set of parts to be useful. The "Base unit" or "Tower" is the main part of the computer. A mouse and keyboard are used for input. A monitor is needed to view output. In a laptop computer these parts are all together.
Inside the base unit or tower there are many electronic parts. The main parts are the motherboard, CPU, the Hard disk and memory.
The CPU (Central Processing unit) follows the instructions in the operating system and application programs. The memory, or RAM (random access memory), is for moving information (or data) quickly to and from the processor. The hard drive holds programs and data while the computer is powered off. Floppy drives, CD-ROM drives are used for storing information on removable disks.
Computers often have a modem to send and receive data over a phone line, or more recently, over cable television lines. Computers can also be connected to a computer network.
Modern PCs have various sockets called ports. The most common ports are known as USB ports.
Computers may be used for work, including doing research using the internet, keeping records; or writing documents. Other uses include communicating, with people across the world using Instant messaging, e-mail or Skype or recreation activity such as playing computer games.
Contents
History
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In the history of computing, early experimental machines could be operated by a single attendant. For example, ENIAC which became operational in 1946 could be run by a single, albeit highly trained, person. This mode pre-dated the batch programming, or time-sharing modes with multiple users connected through terminals to mainframe computers. Computers intended for laboratory, instrumentation, or engineering purposes were built, and could be operated by one person in an interactive fashion. Examples include such systems as the Bendix G15 and LGP-30of 1956, the Programma 101 introduced in 1964, and the Soviet MIR series of computers developed from 1965 to 1969. By the early 1970s, people in academic or research institutions had the opportunity for single-person use of a computer system in interactive mode for extended durations, although these systems would still have been too expensive to be owned by a single person.
In what was later to be called the Mother of All Demos, SRI researcher Douglas Engelbart in 1968 gave a preview of what would become the staples of daily working life in the 21st century: e-mail, hypertext, word processing, video conferencing, and the mouse. The demonstration required technical support staff and a mainframe time-sharing computer that were far too costly for individual business use at the time.
Widespread commercial availability of the microprocessor, starting in the mid 1970's, made computers cheap enough for small businesses and individuals to own.
Early personal computers—generally called microcomputers—were often sold in a kit form and in limited volumes, and were of interest mostly to hobbyists and technicians. Minimal programming was done with toggle switches to enter instructions, and output was provided by front panel lamps. Practical use required adding peripherals such as keyboards, computer displays, disk drives, and printers.
Micral N was the earliest commercial, non-kit microcomputer based on a microprocessor, the Intel 8008. It was built starting in 1972, and a few hundred units were sold. This had been preceded by the Datapoint 2200 in 1970, for which the Intel 8008 had been commissioned, though not accepted for use. The CPU design implemented in the Datapoint 2200 became the basis for x86 architecture used in the original IBM PC and its descendants.
In 1973, the IBM Los Gatos Scientific Center developed a portable computer prototype called SCAMP (Special Computer APL Machine Portable) based on the IBM PALM processor with a Philips compact cassette drive, small CRT, and full function keyboard. SCAMP emulated an IBM 1130 minicomputer in order to run APL/1130. In 1973, APL was generally available only on mainframe computers, and most desktop sized microcomputers such as the Wang 2200 or HP 9800 offered only BASIC. Because SCAMP was the first to emulate APL/1130 performance on a portable, single user computer, PC Magazine in 1983 designated SCAMP a "revolutionary concept" and "the world's first personal computer".
This first single user portable computer now resides in the Smithsonian Institution, Washington, D.C.. Successful demonstrations of the 1973 SCAMP prototype led to the IBM 5100 portable microcomputer launched in 1975 with the ability to be programmed in both APL and BASIC for engineers, analysts, statisticians, and other business problem-solvers. In the late 1960s such a machine would have been nearly as large as two desks and would have weighed about half a ton.
Another desktop portable APL machine, the MCM/70, was demonstrated in 1973 and shipped in 1974. It used the Intel 8008 processor.
A seminal step in personal computing was the 1973 Xerox Alto, developed at Xerox's Palo Alto Research Center (PARC). It had a graphical user interface (GUI) which later served as inspiration for Apple's Macintosh, and Microsoft's Windows operating system. The Alto was a demonstration project, not commercialized, as the parts were too expensive to be affordable.
Also in 1973 Hewlett Packard introduced fully BASIC programmable microcomputers that fit entirely on top of a desk, including a keyboard, a small one-line display, and printer. The Wang 2200 microcomputer of 1973 had a full-size cathode ray tube (CRT) and cassette tape storage. These were generally expensive specialized computers sold for business or scientific uses.
1974 saw the introduction of what is considered by many to be the first true "personal computer", the Altair 8800 created by Micro Instrumentation and Telemetry Systems (MITS). Based on the 8-bit Intel 8080 Microprocessor, the Altair is widely recognized as the spark that ignited the microcomputer revolution as the first commercially successful personal computer. The computer bus designed for the Altair was to become a de facto standard in the form of the S-100 bus, and the first programming language for the machine was Microsoft's founding product, Altair BASIC.
In 1976, Steve Jobs and Steve Wozniak sold the Apple I computer circuit board, which was fully prepared and contained about 30 chips. The Apple I computer differed from the other kit-style hobby computers of era. At the request of Paul Terrell, owner of the Byte Shop, Jobs and Wozniak were given their first purchase order, for 50 Apple I computers, only if the computers were assembled and tested and not a kit computer. Terrell wanted to have computers to sell to a wide range of users, not just experienced electronics hobbyists who had the soldering skills to assemble a computer kit. The Apple I as delivered was still technically a kit computer, as it did not have a power supply, case, or keyboard when it was delivered to the Byte Shop.
The first successfully mass marketed personal computer to be announced was the Commodore PET after being revealed in January 1977. However, it was back-ordered and not available until later that year. Three months later (April), the Apple II (usually referred to as the "Apple") was announced with the first units being shipped 10 June 1977, and the TRS-80 from Tandy Corporation / Tandy Radio Shack following in August 1977, which sold over 100,000 units during its lifetime. Together, these 3 machines were referred to as the "1977 trinity". Mass-market, ready-assembled computers had arrived, and allowed a wider range of people to use computers, focusing more on software applications and less on development of the processor hardware.
In 1977 the Heath company introduced personal computer kits known has Heathkits, starting with the Heathkit H8, followed by the Heathkit H89 in late 1979. With the purchase of the Heathkit H8 you would obtain the chassis and CPU card to assemble yourself, additional hardware such as the H8-1 memory board that contained 4k of RAM could also be purchased in order to run software.The Heathkit H11 model was released in 1978 and was one of the first 16-bit personal computers, however due to its high retail cost of $1,295 was discontinued in 1982.
During the early 1980s, home computers were further developed for household use, with software for personal productivity, programming and games. They typically could be used with a television already in the home as the computer display, with low-detail blocky graphics and a limited color range, and text about 40 characters wide by 25 characters tall. Sinclair Research, a UK company, produced the ZX Series—the ZX80 (1980), ZX81 (1981), and the ZX Spectrum; the latter was introduced in 1982, and totaled 8 million unit sold. Following came the Commodore 64, totaled 17 million units sold and the Amstrad CPC series (464-6128).
In the same year, the NEC PC-98 was introduced, which was a very popular personal computer that sold in more than 18 million units. Another famous personal computer, the revolutionary Amiga 1000, was unveiled by Commodore on July 23, 1985. The Amiga 1000 featured a multitasking, windowing operating system, color graphics with a 4096-color palette, stereo sound, Motorola 68000 CPU, 256 KB RAM, and 880 KB 3.5-inch disk drive, for US$1,295.
Somewhat larger and more expensive systems were aimed at office and small business use. These often featured 80-column text displays but might not have had graphics or sound capabilities. These microprocessor based systems were still less costly than time-shared mainframes or minicomputers.
Workstations were characterized by high-performance processors and graphics displays, with large-capacity local disk storage, networking capability, and running under a multitasking operating system. Eventually, due to the influence of the IBM PC on the personal computer market, personal computers and home computers lost any technical distinction. Business computers acquired color graphics capability and sound, and home computers and game systems users used the same processors and operating systems as office workers. Mass-market computers had graphics capabilities and memory comparable to dedicated workstations of a few years before. Even local area networking, originally a way to allow business computers to share expensive mass storage and peripherals, became a standard feature of personal computers used at home.
IBM's first PC was introduced Aug. 12, 1981.
In 1982 "The Computer" was named Machine of the Year by Time magazine. In the 2010s, several companies such as Hewlett-Packard and Sony sold off their PC and laptop divisions. As a result, the personal computer was declared dead several times during this period.
In 1991, the World Wide Web was made available for public use. The combination of powerful personal computers with high resolution graphics and sound, with the infrastructure provided by the Internet, and the standardization of access methods of the Web browsers, established the foundation for a significant fraction of modern life, from bus time tables through to an online Kids encyclopedia.
Types
Stationary
A workstation is a high-end personal computer designed for technical, mathematical, or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems. Workstations are used for tasks such as computer-aided design, drafting and modeling, computation-intensive scientific and engineering calculations, image processing, architectural modeling, and computer graphics for animation and motion picture visual effects.
Desktop computer
Before the widespread use of PCs, a computer that could fit on a desk was remarkably small, leading to the "desktop" nomenclature. More recently, the phrase usually indicates a particular style of computer case. Desktop computers come in a variety of styles ranging from large vertical tower cases to small models which can be tucked behind an LCD monitor.
The term "desktop" typically refers to a computer with a vertically aligned computer case that holds the systems hardware components such as the motherboard, processor chip, other internal operating parts. Desktop computers have an external monitor with a display screen and an external keyboard, which are plugged into USB ports on the back of the computer case. Desktop computers are popular for home and business computing applications as they leave space on the desk for multiple monitors.
A gaming computer is a desktop computer that has a high-performance video card, processor and memory, to improve the speed and responsiveness of demanding video games.
An all-in-one computer (also known as single-unit PCs) is a desktop computer that combines the monitor and processor within a single unit. A separate keyboard and mouse are standard input devices, with some monitors including touchscreen capability. The processor and other working components are typically reduced in size relative to standard desktops, located behind the monitor, and configured similarly to laptops.
A nettops computer was introduced by Intel in February 2008, characterized by low cost and lean functionality.These were intended to be used with an Internet connection to run Web browsers and Internet applications.
A Home theater PC (HTPC) combines the functions of a personal computer and a digital video recorder. It is connected to a TV set or an appropriately sized computer display, and is often used as a digital photo viewer, music and video player, TV receiver, and digital video recorder. HTPCs are also referred to as media center systems or media servers. The goal is to combine many or all components of a home theater setup into one box. HTPCs can also connect to services providing on-demand movies and TV shows. HTPCs can be purchased pre-configured with the required hardware and software needed to add television programming to the PC, or can be assembled from components.
Portable
The potential utility of portable computers was apparent early on. Alan Kay described the Dynabook in 1972, but no hardware was developed. The Xerox NoteTaker was produced in a very small experimental batch around 1978. In 1975, the IBM 5100 could be fit into a transport case, making it a portable computer, but it weighed about 50 pounds.
IBM PC-compatible suitcase format computers became available soon after the introduction of the PC, with the Compaq Portable being a leading example of the type. Later models included a hard drive to give roughly equivalent performance to contemporary desk top computers.
The development of thin plasma display and LCD screens permitted a somewhat smaller form factor, called the "lunchbox" computer.
Notebook computers such as the TRS-80 Model 100 and Epson HX-20 had roughly the plan dimensions of a sheet of typing paper (ANSI A or ISO A4). These machines had a keyboard with slightly reduced dimensions compared to a desktop system, and a fixed LCD display screen coplanar with the keyboard. Later, clam-shell format laptop computers with similar small plan dimensions were also called "notebooks".
Laptop
A laptop computer is designed for portability with "clamshell" design, where the keyboard and computer components are on one panel, with a hinged second panel containing a flat display screen. Closing the laptop protects the screen and keyboard during transportation. Laptops generally have a rechargeable battery, enhancing their portability. To save power, weight and space, laptop graphics cards are in many cases integrated into the CPU or chipset and use system RAM, resulting in reduced graphics performance when compared to a desktop machine. For this reason, desktop computers are usually preferred over laptops for gaming purposes.
Unlike desktop computers, only minor internal upgrades (such as memory and hard disk drive) are feasible owing to the limited space and power available. Laptops have the same input and output ports as desktops, for connecting to external displays, mice, cameras, storage devices and keyboards. Laptops are also a little more expensive compared to desktops, as the miniaturized components for laptops themselves are expensive.
A desktop replacement computer is a portable computer that provides the full capabilities of a desktop computer. Such computers are currently large laptops. This class of computers usually includes more powerful components and a larger display than generally found in smaller portable computers, and may have limited battery capacity or no battery.
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Netbooks, also called mini notebooks or subnotebooks, are a subgroup of laptops suited for general computing tasks and accessing web-based applications. Initially, the primary defining characteristic of netbooks was the lack of an optical disc drive, smaller size, and lower performance than full-size laptops. By mid-2009 netbooks had been offered to users "free of charge", with an extended service contract purchase of a cellular data plan.
Tablet
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A tablet uses a touchscreen display, which can be controlled using either a stylus pen or finger. Some tablets may use a "hybrid" or "convertible" design, offering a keyboard that can either be removed as an attachment, or a screen that can be rotated and folded directly over top the keyboard. Some tablets may use desktop-PC operating system such as Windows or Linux, or may run an operating system designed primarily for tablets. Many tablet computers have USB ports, to which a keyboard or mouse can be connected.
Smartphone
Smartphones are often similar to tablet computers, the difference being that smartphones always have cellular integration. They are generally smaller than tablets, and may not have a slate form factor.
Ultra-mobile PC
The ultra-mobile PC (UMP) is a small tablet computer. It was developed by Microsoft, Intel and Samsung, among others. Current UMPCs typically feature the Windows XP, Windows Vista, Windows 7, or Linux operating system, and low-voltage Intel Atom or VIA C7-M processors.
Pocket PC
A pocket PC is a hardware specification for a handheld-sized computer (personal digital assistant, PDA) that runs the Microsoft Windows Mobile operating system. It may have the capability to run an alternative operating system like NetBSD or Linux. Pocket PCs have many of the capabilities of desktop PCs.
Hardware
- Scanner
- CPU (microprocessor)
- Memory (RAM)
- Expansion cards (graphics cards, etc.)
- Power supply
- Optical disc drive
- Storage (hard disk or SSD)
- Motherboard
- Speakers
- Monitor
- System software
- Application software
- Keyboard
- Mouse
- External hard disk
- Printer
Computer hardware is a comprehensive term for all physical parts of a computer, as distinguished from the data it contains or operates on, and the software that provides instructions for the hardware to accomplish tasks. Some sub-systems of a personal computer may contain processors that run a fixed program, or firmware, such as a keyboard controller. Firmware usually is not changed by the end user of the personal computer.
Most 2010s-era computers only require users to plug in the power supply, monitor, and other cables. A typical desktop computer consists of a computer case (or "tower"), a metal chassis that holds the power supply, motherboard, hard disk drive, and often an optical disc drive. Most towers have empty space where users can add additional components. External devices such as a computer monitor or visual display unit, keyboard, and a pointing device (mouse) are usually found in a personal computer.
The motherboard connects all processor, memory and peripheral devices together. The RAM, graphics card and processor are in most cases mounted directly onto the motherboard.
The central processing unit (microprocessor chip) plugs into a CPU socket, while the memory modules plug into corresponding memory sockets. Some motherboards have the video display adapter, sound and other peripherals integrated onto the motherboard, while others use expansion slots for graphics cards, network cards, or other I/O devices.
The graphics card or sound card may employ a break out box to keep the analog parts away from the electromagnetic radiation inside the computer case. Disk drives, which provide mass storage, are connected to the motherboard with one cable, and to the power supply through another cable. Usually, disk drives are mounted in the same case as the motherboard; expansion chassis are also made for additional disk storage.
For large amounts of data, a tape drive can be used or extra hard disks can be put together in an external case. The keyboard and the mouse are external devices plugged into the computer through connectors on an I/O panel on the back of the computer case. The monitor is also connected to the input/output (I/O) panel, either through an onboard port on the motherboard, or a port on the graphics card.
A peripheral is "a device connected to a computer to provide communication (such as input and output) or auxiliary functions (such as additional storage)". Peripherals generally connect to the computer through the use of USB ports or inputs located on the I/O panel. USB Flash Drives provide portable storage using flash memory which allows users to access the files stored on the drive on any computer.
Memory cards also provide portable storage for users, commonly used on other electronics such as mobile phones and digital cameras, the information stored on these cards can be accessed using a memory card reader to transfer data between devices.
Webcams, which are either built into computer hardware or connected via USB are video cameras that records video in real time to either be saved to the computer or streamed somewhere else over the internet. Game controllers can be plugged in via USB and can be used as an input device for video games as an alternative to using keyboard and mouse.
Headphones and speakers can be connected via USB or through an auxiliary port (found on I/O panel) and allow users to listen to audio accessed on their computer, however speakers may also require an additional power source to operate. Microphones can be connected through an audio input port on the I/O panel and allow the computer to convert sound into an electrical signal to be used or transmitted by the computer.
Software
Computer software is any kind of computer program, procedure, or documentation that performs some task on a computer system. The term includes application software such as word processors that perform productive tasks for users, system software such as operating systems that interface with computer hardware to provide the necessary services for application software, and middleware that controls and co-ordinates distributed systems.
Software applications are common for word processing, Internet browsing, Internet faxing, e-mail and other digital messaging, multimedia playback, playing of computer game, and computer programming.
Operating system
An operating system (OS) manages computer resources and provides programmers with an interface used to access those resources. An operating system processes system data and user input, and responds by allocating and managing tasks and internal system resources as a service to users and programs of the system. An operating system performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating computer networking, and managing files.
Common contemporary desktop operating systems are Microsoft Windows, macOS, Linux, Solaris and FreeBSD. Windows, macOS, and Linux all have server and personal variants. With the exception of Microsoft Windows, the designs of each of them were inspired by or directly inherited from the Unix operating system.
Early personal computers used operating systems that supported command line interaction, using an alphanumeric display and keyboard. The user had to remember a large range of commands to, for example, open a file for editing or to move text from one place to another. Starting in the early 1960's, the advantages of a graphical user interface began to be explored, but widespread adoption required lower cost graphical display equipment. By 1984, mass-market computer systems using graphical user interfaces were available; by the turn of the 21st century, text-mode operating systems were no longer a significant fraction of the personal computer market.
Applications
Generally, a computer user uses application software to carry out a specific task. System software supports applications and provides common services such as memory management, network connectivity and device drivers, all of which may be used by applications but are not directly of interest to the end user.
A simple way of explaining the relationship between the computer and system software is the example of an electric light bulb (an application) to an electric power generation plant (a system): the power plant only generates electricity, and isn't of any real use itself until it's harnessed to an application like the electric light bulb that performs a service that benefits the user.
Typical examples of software applications are word processors, spreadsheets, and media players. Multiple applications bundled together as a package are sometimes referred to as an application suite. Microsoft Office and LibreOffice, which bundle together a word processor, a spreadsheet, and several other discrete applications, are typical examples.
Gaming
PC gaming is popular among the more expensive PC market.
Environmental impact
External costs of environmental impact are not fully included in the selling price of personal computers.
Personal computers have become a large contributor to the 50 million tons of discarded electronic waste generated annually, according to the United Nations Environment Programme.
Images for kids
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An artist's depiction of a 2000s-era desktop-style personal computer, which includes a metal case with the computing components, a display monitor and a keyboard (mouse not shown)
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The 8-bit architecture Pravetz 82 computer produced in Bulgaria from 1982, in school class in the Soviet Union
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A portable computer Cambridge Z88 released in 1987
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A laptop computer
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A screenshot of the LibreOffice Writer software
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A screenshot of Krita, which is a raster graphics editor.
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Children being taught how to use a laptop computer in 2005. An older (1990s-era) desktop personal computer's CRT monitor is visible in the background.
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Personal computers worldwide in million distinguished by developed and developing world
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See also
In Spanish: Computadora personal para niños
