A personal computer is a multi-purpose device, the size, capabilities and price of which make it available for individual use. The main characteristics of a PC are intended for use by an end user, not a computer expert or specialist. The first computer owners in the 1960s had to write their own programs for any useful machine work. Now the software, as well as the main technical specifications of PCs, are usually developed and distributed independently of equipment manufacturers or OS.
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Since the early 1990s, Microsoft operating systems and Intel hardware have dominated the personal computer market, first with MS-DOS and then with Windows. Alternatives to Microsoft Windows operating systems occupy a smaller share in the industry. These include Apple's MacOS and free Unix-like open source operating systems such as Linux. Advanced Micro Devices (AMD) provides the primary alternative to Intel processors.
How a PC works: basic PC features
Each fully functional computer consists of the same basic components. We list the main characteristics of the PC and the main components:
CPU;
motherboards;
housing;
RAM;
graphic card;
HDD;
optical drive;
power supply.
Also, the basic equipment provides peripheral equipment depending on the user's goals. The main characteristics of the PC are presented in detail below - for the 7th grade of the school this will be most useful when studying the equipment design.
Computer case
The computer case is a "box" containing the main components. It is usually made of steel or aluminum in combination with plastic, although other materials such as wood and tempered glass are used for specialized solutions. Case boxes are available in different sizes and shapes, which are usually determined by the configuration of the motherboard, as it is the largest and most central component of most computers.
Power Supply
The power supply unit (PSU) as the main characteristic of a PC converts general-purpose alternating current electricity into direct current (DC) for other computer components. The rated output power of the power supply should usually be approximately 40% greater than the calculated power consumption of the systems. This protects against overload and performance degradation. The PC device and its main characteristics provide a power capacity of 250 to 2000 watts.
CPU
A central processing unit (CPU) is part of a computer that executes software instructions. On newer PCs, the processor contains more than a million transistors in a single integrated circuit chip called a microprocessor. In most cases, it connects directly to the motherboard. The processor chip may have a heatsink and fan for cooling. IBM PC compatible computers use an x86 compatible microprocessor from Intel, AMD, VIA Technologies, or Transmeta. Initially, Apple Macintosh computers were built using the Motorola 680x0 processor families, and then switched to the PowerPC series. In 2006, they switched to x86-compatible Intel processors.
Motherboard
The motherboard is the main printed circuit board in the personal computer and determines the purpose, composition and basic characteristics of the PC. Other main components of the system are connected directly to it or via cable. The motherboard contains a microprocessor that supports the CPU (mainly integrated circuits), which provide an interface between the memory and peripheral I / O circuits, the main memory and the means for initial configuration of the computer immediately after turning on the power. In many portable and integrated personal computers, the motherboard accommodates almost all of the main components of a PC. Often, the motherboard also contains one or more peripheral buses and physical connectors for expansion. Sometimes a secondary daughterboard is connected to it to provide additional extensibility.
Main memory
The main memory of a PC is an online primary storage device that is directly accessible by the CPU and is used to store the current executable program and the necessary data. Various types of semiconductor random access memory (RAM) are used as the main PC storage, such as DRAM, SDRAM or SRAM. Which type is used depends on cost and performance issues at any given time. RAM is much faster than mass storage devices, such as hard or optical drives, but is usually unstable, which means that it does not retain its contents (instructions or data) in the absence of power. As a result, the main memory is usually not suitable for long-term storage of information or archive data.
HDD
Storage devices contain programs and data, even when the power is turned off. They require power to perform read and write functions during use. If the mass storage controller provides additional ports for expansion, the PC can also be upgraded by adding additional hard or optical drives. The standard interfaces for connecting an internal storage device are PATA, SATA and SCSI. Solid State Drives (SSDs) are a much faster replacement for traditional mechanical hard drives, but also more expensive in terms of cost per gigabyte.
Visual display
A computer monitor, or simply a display, is a piece of electrical equipment, usually separate from the computer case, that displays visual images without creating a permanent computer recording. The display contains an electronic circuit that generates an image from signals received from a computer. Inside the PC that is built into the motherboard or connected to it as an expansion card, there is a preprocessing circuit for converting the microprocessor output into a format compatible with the display circuit. Initially, images from computer monitors contained only text, but as graphical user interfaces appeared, they began to show more images and multimedia content.
Video card
A video card, otherwise called a graphics card, graphics adapter or video adapter, processes the graphic output from the motherboard and transfers it to the display. This is an integral part of modern multimedia computing. The graphics scheme can be integrated with the motherboard or it can be on cards in PCI, AGP or PCI Express slots.
Keyboard
The computer keyboard as the main characteristic of a PC is a combination of buttons, each of which corresponds to a function, letter or number. They are the main devices used to enter text. In most cases, they contain an array of keys specially organized with the corresponding letters, numbers and functions printed or engraved on the button. They are usually designed in the language of operators, and there are many different versions for different languages.
In English, the most common layout is the QWERTY layout, which was originally used in typewriters. They evolved over time and have been modified for use on computers with the addition of function and number keys, arrow keys, and buttons related to the operating system. In addition to the alphabetic keys, computer keyboards usually have a numeric keypad and a number of function keys and special keys such as CNTRL, ALT, DEL and Esc.
Many keyboards include LED indicators under the keys, which increase the visibility of letters or characters in low light conditions.
Computer mouse
The computer mouse as the main characteristic of a PC is a small device that users hold and slide on a flat surface, pointing to various elements of the graphical interface using the on-screen cursor, and also select and move objects using buttons. Mice can be connected to a special connector or to a USB port, and can also be connected wirelessly. The device includes one or more buttons that allow the user to signal the computer to perform any operation, for example, selecting an item from the menu of options on the screen. The mouse may have a scroll wheel so that users can move the displayed image. The scooter can also be pressed and used as a third button. Some mouse wheels can tilt side to side to allow side scrolling.
Mechanical mice used a ball that pulsed generators to detect movement along the north-south or east-west axes. Optical mice use a special mouse pad with a printed network that allows you to detect movement, or use an image-forming chip that allows you to detect movement on almost any opaque surface.
operating system
An operating system (OS) manages computer resources and provides programmers with an interface used to access these resources. It processes system data and user input and responds by distributing and managing tasks and internal system resources as a service for users and programs. The operating system performs basic tasks such as managing and allocating memory, prioritizing system queries, managing input and output devices, simplifying computer networks, and managing files.
Common modern desktop operating systems are Microsoft Windows, MacOS, Linux, Solaris, and FreeBSD. Windows, MacOS, and Linux.