Hardware:Input / Output Devices

Topics to be discussed…..

Input Devices Output Devices BIOS Input Output Storage Devices Sequential vs. Random Access Storage Storage Technologies: Magnetic and Optical

Input Devices An input device is any hardware component that allows you

to enter data and instructions onto a computer. Six Widely used input devices are the keyboard, mouse, microphone, scanner, digital camera and PC video camera.

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Output Devices

An output device is any hardware component that conveys information to one or more people. Three commonly used output devices are a printer, a monitor and speakers.

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BIOS

Acronym for basic input/output system, the built-in software that determines what a computer can do without accessing programs from a disk. On PCs, the BIOS contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions.

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Input

Input is any data entered into the computer’s memory. Types of input include:

◦ Data – Unorganized information (words, numbers, images, or sounds) that the computer converts to meaningful information

◦ Software – Programs transferred from storage devices to the computer’s memory

◦ Commands – Instructions that tell the computer what to do

◦ Responses – Prompts requiring user feedback

Input Devices• Input device captures information and translates it into a form that can be processed and used by other parts of your computer. KeyboardsPointing devicesGame controllersScannersStylusesMicrophonesDigital camerasWeb cams

p. 5.130 Fig. 5-1

SimNet Concepts Support CD: “Overview of Input Devices” and “Other Everyday Input Devices”

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Output

What is Output?

Output is data that has been processed into a useful form.

Output devicesMonitors:

screens or Visual Display Units (VDUs)display the effects of what the user is doingcan vary in size and resolution.

Printers:produce a paper copy of the user’s work: a ‘hard copy’come in three main types: laser, inkjet and dot matrix. Some businesses also use plotters.

Sometimes we just need to see the information, on screen or on paper, so we

use a monitor or a printer.

Device Benefits

CRT Cheapest monitor to buy; gives a sharp picture

LCD Slim screen; Used for laptops and digital display

TFT Slim screen; quick to refresh because each pixel has its own transistor

Speakers Good for loud music; can address a whole room

Headphones Can listen without disturbing others; good for private conversation

Laser Quick and best quality printer; large paper tray

Inkjet Cheap colour printing; good for printing photos

Dot matrix Impact printer; good for multi-part forms

Plotter Large drawing size; clear lines for technical drawings

Control Safe in all conditions; good for repetitive tasks

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Storage Devices Storage devices are categorized by:

◦The type of operations they perform

◦The method they use to access the information

◦The technology they use

◦Their location in the storage hierarchy

◦Their capacity and speed

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Sequential vs. Random Access Storage

Sequential – Storage devices that read and write data in a serial (one after the other) fashion

Random-Access – Storage devices that read and write data without going through a sequence of locations

Tape Drive – sequential storage

Hard Disk – random-access storage

Floppy Disk Drive – random-access storage

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Storage Technologies: Magnetic and Optical

Magnetic – Storage devices use disks or tapes that are coated with magnetically sensitive material

Optical – Storage devices that use laser beams to read patterns etched into plastic disks

Magnetic Storage Optical Storage – CD/DVD drive

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Thank You