Computer - Hardware components

Computer Hardware Components - Internal hardware and External hardware

1. Computer – Hardware Components

2. A computer is a machine that can perform a variety of operations in accordance with a set of instructions called program. It processes the input data given by the programmer/user and provides the desired information as output. Computer System

3. Computers have made life easier for everyone in the world. They are being used everywhere in nearly all the fields such as banking, railways, airways, hotels, schools, colleges, shops, industries, defence and designing. Computers are mainly used in :-

4. Computer System Computer works with an interaction of hardware and software. Both hardware and software are dependent on each other. Devices like CPU, memory unit and hard disk are useless unless they are provided with instructions and data for storage and processing.

5. Hardware refers to any physical component of a computer. Monitor, keyboard and hard disk are physical components and thus, are hardware. The most important piece of hardware is a CPU. It is called the ‘brain’ of the computer.

6. Software refers to the programs, which are required to operate the computer. Windows, Windows media player, Google Chrome and Microsoft Office are all software. Software

7. Hardware is classified into two types:

8. Internal Hardware -The hardware parts that are installed within the CPU cabinet are called internal hardware. Motherboard, CPU, RAM, ROM and sound card are some examples of internal hardware. Internal Hardware

9. A motherboard is a sheet of plastic that holds all the circuitry to connect various components of a computer system. It is one of the most essential parts of a computer system. It holds together many crucial components of a computer, including the CPU, memory and connectors for input and output devices. In addition to circuits, motherboard contains a number of sockets and slots to connect other components. All the activities related to the connected devices start and end in the motherboard. Motherboard

10. A motherboard mainly consists of the following. • Processor chip • BIOS • Memory chips • External storage controllers for video display and audio • Expansion slots for connecting additional circuit boards Motherboard

11. Sound Card Sound cards are also known as audio adapters. A sound card is an expansion component used in computers to receive and send audio. Sound cards are configured and utilised with the help of a software and a device driver. The input device attached to receive audio data is usually a microphone, whereas the devices used for audio output are generally speakers and headphones. Sound Card

12. The sound card converts incoming digital audio data into analog audio so that the speakers can play it. In the reverse case, the sound card can convert analog audio data from the microphone into digital data that can be stored on the computer. Sound Card

13. Video Card A video card is also known as a graphics card. It is an expansion card connected to a motherboard, that is used to generate the video output on a screen such as monitor and television. It enhances the quality of the displayed images, and contains its own processing and memory unit. Video Card

14. CPU The Central Processing Unit (CPU) is the primary element of a computer. It carries out each instruction of a program in a sequence to perform the basic operations of the system. In other words, it performs arithmetic and logical calculations of the data. The CPU is capable of storing enormous amount of data and processing them at a high speed and producing useful results. CPU - Central Processing Unit

15. The three components of a CPU are listed below. Arithmetic Logic Unit (ALU): It performs arithmetic and logical operations. 2. Control Unit (CU): It extracts instructions from the memory, decodes and executes them. 3. Memory Unit (MU): A computer has a large storage capacity. The storage capacity of a computer is called its memory. Memory enables a computer to store data and instructions. CPU - Central Processing Unit

16. RAM Random Access Memory (RAM) is used to store data and instructions during the execution of programs. RAM is temporary and is erased when a computer is switched off . Hence, RAM is a volatile memory. It is a read/ write type of memory, and thus can only be read and written by the user/programmer. As it is possible to randomly use any location of this memory, therefore, this memory is known as random access memory. RAM

17. Two types of RAM are used in PCs: dynamic RAM and static RAM. • Dynamic RAM (DRAM): The information stored in dynamic RAM has to be refreshed after every few milliseconds, otherwise it is erased. DRAM is mostly used for system memory because it is cheaper and has a higher storage capacity than static RAM. • Static RAM (SRAM): The information stored in static RAM need not be refreshed, but it remains stable as long as the power supply is provided. SRAM is costlier but has a higher speed than DRAM. RAM

18. ROM Read Only Memory (ROM) is an essential component of the memory unit. A computer, being a machine, itself has no intelligence or memory and it requires instructions which are given by man. Whenever a computer is switched on, it searches for the required instructions. The memory consisting of these essential instructions is known as read only memory. This memory is permanent and is not erased when the system is switched off . So, ROM is a non-volatile memory. As is clear from its name, it is read type of memory, i.e., it can be read only and not be written by user/programmer. ROM

19. Types of ROM There are various types of ROM available for microcomputers like PROM, EPROM and EEPROM. • PROM: It stands for Programmable Read Only Memory. In this type of ROM, the information is stored by programmers after its manufacturing. It cannot be altered or erased later on. ROM

20. • EPROM: It stands for Erasable Programmable Read Only Memory. It is similar to PROM, but its information can be erased later on by ultraviolet light and it can be reprogrammed. EPROM

21. • EEPROM: It stands for Electrically Erasable Programmable Read Only Memory. It is similar to EPROM but its information can be erased by using a high voltage current. EEPROM

22. Disk Drive A disk drive enables the users to read, write, delete and modify data on a storage disk. It manages the input/output operations of the disk. It can be either external or inbuilt component of a disk. The most common type of disk drive is a hard drive, but several other types of disk drives exist as well. Some examples include removable storage devices, floppy drives and optical drive DISK DRIVE

23. Switched Mode Power Supply (SMPS) SMPS is essential for safe running of power-consuming appliances. Switching power supplies have high efficiency and are widely used in a variety of electronic equipments , including computers and other sensitive equipments requiring stable and efficient power supply. It also contains inbuilt fans to release excessive heat generated during the computer use. SMPS

24. MODEM The term MODEM is formed by combining the words MO- dulation and DEM- odulation . MODEM is a data communication equipment that translates the digital signals used by a computer into analog signals of the kind that travel by conventional telephone lines. The process of translating digital signals into analog signals is called modulation. MODEM

25. A MODEM also converts the analog signals into digital signals at the receiving end of a computing device. The process which translates analog signals into digital signals is called demodulation. The basic function of a MODEM is to enable communication between various computers on a network (mainly Internet). MODEM

26. There are mainly two types of MODEM: internal and external. An internal MODEM is a card that is installed into a slot within the CPU case of a computer. Internal modem is powered by the power supply of a computer. An external MODEM is a box-shaped device that is connected to the serial port of a computer. It is so called as it is placed outside the computer. The external modem is powered by an external power adapter, connected to an electrical outlet. MODEM

27. Heat Sink A heat sink is an electronic device designed to disperse the heat generated by the CPU and cools it for improving performance and reliability. It also avoids the premature failure of the components. HEAT SINK

28. Port A computer port is a connection between a computer and an external or internal device. Internal ports may connect devices such as hard drives and CD ROM or DVD drives. External ports may connect modems, printers, mouse and other devices. PORT Definition Ports are connecting sockets, used to connect peripheral devices on the system unit. Description Hardware ports are usually male or female type. Software ports are virtual or logical connection needed to exchange information between the programs. Several hardware ports are available at backside of the cabinet like keyboard, mouse, monitor, printer, modem etc.

29. Characteristics of Ports A port has the following characteristics. • External devices are connected to a computer using cables and ports. • Ports are slots on the motherboard into which the cable of an external device is plugged in. Computer ports have numerous functions and connectors of varying designs. PORTS

30. Serial Port Serial port involves the transmission of data one bit at a time over a single communication line. Use: It is used for external MODEM and older computer mouse that do not require high speed transmission. PORTS

31. 2. Parallel Port Parallel port transfers the data in or out in parallel using more than one communication line or wire. To connect external devices that sends lot of data over a short distance. Sends 8 bit data simultaneously over 8 pins. Use: It is used for scanners and printers that require high speed transmission. PARALLEL PORTS

32. 3. PS/2 Port PS/2 port is also called mouse port. PS/2 port is now considered a legacy port as the USB port has replaced it and very few modern motherboards include it as a legacy port. Use: It is used for old computer keyboard and mouse. Most of the old computers provide two PS/2 port, one for the mouse and one for keyboard. PS/2 PORTS

33. 4. Universal Serial Bus (USB) USB can connect all kinds of external USB devices such as external hard disk, printer, scanner, mouse and keyboard. Use: It is used to transfer data and also act as a power supply for devices connected to it. UNIVERSAL SERIAL BUS (USB) PORTS

34. 5. Video Graphics Array (VGA) VGA port is the main interface between computers and older CRT monitors. It is similar to the serial port connector that has pins. However, VGA port has holes. Even modern LCD and LED monitors support VGA ports but the picture quality is reduced. VGA – VIDEO GRAPHICS ARRAY

35. 5 With the increase in the use of digital video, VGA ports are gradually being replaced by HDMI and display ports. Some laptops are equipped with on-board VGA ports in order to connect to external monitors or projectors. Use: It connects monitor to a computer’s video card. VGA – VIDEO GRAPHICS ARRAY HDMI PORT DISPLAY PORT

36. 6. Firewire Port Firewire port is developed by Apple. It transfers large amount of data at a very fast speed. Use: It connects camcorders and video equipments to the computer. FIREWIRE PORT

37. 7. Ethernet port resides on an ethernet card. Data travels at 10 megabits to 1000 megabits per second depending upon the network bandwidth. Use: It connects the network cable to a computer. It connects to a network and high speed Internet. Ethernet ports: Also called as RJ45 ports. Most computer and laptop includes one built-in Ethernet port for connecting to a wired Local Area Network (LAN). Data rate speed varies from 10 MBPS - 1000 MBPS depending upon the type of port used like 10BaseT - 10 MBPS, 100BaseT - 100 MBPS and Giga Ethernet - 1000 MBPS. ETHERNET PORT

38. External hardware are also called peripherals. The devices attached to the computer externally are called external hardware. Input devices, output devices and storage devices are examples of external hardware. External Hardware

39. Input devices feed information, data and instructions to a computer. The computer accepts and processes them before giving the output. Input Devices

40. Keyboard, the most common and essential input device of a computer is similar to a typewriter. However, there are more keys present on a computer keyboard than on a typewriter. The most commonly used keyboard (QWERTY keyboard) has 105 keys. Keyboard

41. A keyboard consists of five types of keys. Typing keys: They consist of :- Alphabet keys (A–Z) Number keys (0–9) Punctuation keys (?, >, <, etc.) Special symbols keys (&, #, etc.). These keys also include Caps Lock, Shift, Backspace, Enter, Spacebar and Tab keys. Keyboard Keyboard

42. • Control keys: They can either be used alone or in combination with other keys to perform an action. Ctrl, Alt and Esc are some control keys. • Function keys: There are 12 keys that are present at the top row of the keyboard and are used to perform specific tasks. F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11 and F12 are the function keys. Keyboard

43. • Navigation keys: They are used to move through the document. Home, Insert, End and Arrow keys are the navigation keys. • Numeric keypad: It is placed at the right side of the keyboard. It consists of number key 0–9, arithmetic operators and the decimal point. Keyboard