Computer Basics

Computer Hardware

Computer Hardware: It refers to the physical parts of the computer:
• Power Supply Unit
• Computer case
• Internal devices
• Input devices
• Output devices
• Storage devices

Computer case:
• Most of the computer components are enclosed in the case
• This is mostly for desktop pcs as laptops come with outer housing which protect them
• It provides support for the components
• It keeps the computer cool
• Reduce the noise

Power Supply Unit:
• It converts the alternating current to direct current
• Regulates overheating by controlling voltage
• Laptops has built-in rechargeable battery

Internal devices:
• CPU (Central processing unit) performs the arithmetic, logical and input/output operations. This is the brain of the computer.
• RAM (Random Access memory) that has data and instructions actively used by CPU
• ROM (Read only memory) is non-volatile memory that stores software that is rarely changed. For example “BIOS” which boots the computer when switched on
• Graphics card that process computer graphics
• Buses that connect CPU to other internal components
• CMOS (complementary metal-oxide-semiconductor) battery for CMOS memory that powers the CMOS memory for date and time

•The CPU, RAM, ROM, Buses, Graphics card and CMOS are on the Motherboard

Input devices:
• Information is provided to the computer through input devices
• Keyboard is a text input device
• Pointing devices
 Mouse is a pointing device moved on a surface
 Trackball is like mouse but a ball is rolled
 Touch screen is on computer screen which is operated by touch
 Touchpad is a flat surface on computer operated by moving finger on it
• Composite devices (having more than 2 different forms of input)
 Joystick is a pivoting stick which is on a base that is stationary
 Paddle is a game controller having a dial and a button
 Gamepad used to play video games
• Voice input devices (capture sound)
 Microphones
 Digital musical instruments
• Video input devices
 Digital cameras
 Digital camcorders
 Webcams
 Scanners (image, fingerprint)
 Barcode reader
 Eye gaze tracker

Output devices:
• Output device outputs the information from computer to the user
• Monitors
• Printers
• GPS
• Projectors
• Speakers
• headphones

Storage devices:
• Storage device stores the data and information
• RAM (Random Access memory) that has data and instructions used by CPU
• The cache memory temporarily holds the instructions and data required by CPU.
• Hard disk drive
• CDs
• DVDs
• Blu-ray discs
• USBs

Expansion cards are printed circuit boards that can be inserted into expansion slot on mother board to add functionality