Lecture # 3

Primary Components

Input devices

• In computing, an input device is any peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system such as a computer.

Input Devices

• Key board• Mouse• Mice• Web cam• Scanner• Pointing devices

Output Devices

• Any peripheral that receives or displays output from computer.

• Flat panel• Monitor• Printer• Projector• Sound card• Speakers• Video card

Resolution

• Sharpness and clarity of image• The higher the resolution, the better the

image quality• Pixel (picture element) is single point in

electronic image• Greater the number of pixels, the better the

image quality

What is the resolution of a printer?

• Measured by number of dots per inch (dpi) printer can output

Types of Printer

• Impact Printers• Nonimpact Printers

Impact Printers

• Impact printer that produces printed images when tiny wire pins strike ribbon

• Impact printer forms characters by striking mechanism against inked ribbon that contacts paper

Impact Printers

• Two commonly used types of impact printers:

• Dot-matrix Printers• Line Printers

Nonimpact Printers

• Nonimpact printer sprays tiny drops of liquid ink onto paper or use heat or pressure to create image.

• Nonimpact printer forms characters and graphics without striking paper.

Types of Nonimpact Printer

• Ink-Jet Printers• Laser Printers• Thermal Printers• Plotters

Memory and Storage

• Both terms are used to refer to internal storage space on a computer. Memory, usually referred to as Random Access Memory (RAM), is the place where an application loads its data during processing, while a hard disk drive is usually the place where data is stored for long or short term retention.