Fundamentals Of Hardware And Software

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Fundamentals of

Hardware and Software

INPUT DEVICES AND MEDIAS

Input

This is what you put into the

computer. Input may also refer to data,

software or instructions that you enter into the computer’s memory.

Input Media/Source Document

This is the place from which you

enter data. Example, you are typing an

essay that is hand written on folder leaves.

Having the test written on folder and will be entering data from it, it

will be called the Input Media or the Source Document. Examples of Input Medias are: Bar Codes/Universal Product Code, Price Tags,

Labels, etc.

Input Devices

These are devices used to transfer

data from sources outside the computer to the main store of the computer system

(RAM) for processing.

Input devices are used to enter raw data, programs or images into a form

that can be processed by a computer.

These devices may also be described as those hardware components that

enable you to get programs, data, commands and responses into the computer’s

memory. The two (2) most commonly used

input devices are keyboards and mouse.

Input Devices may be categorised as Point and Draw Devices, Keying

Devices, Scanning and Source Data Entry Devices, Gaming Devices, Voice Input

Devices, Sensor Input Devices and Vision Input Devices.

Types of Input

Devices

KEYING DEVICES

Keyboard

Keyboards are used to key in data

into the computer for processing. The

keyboard is comprised of several groups of keys arranged in a configuration

similar to that of a typewriter. The

Keyboard is one of the two most common input devices found with computers. The Wireless Keyboards are becoming

popular as it uses infrared technology, a technology similar to

what TV remotes uses.

The keyboard has

four main parts. They are as follows:

a. Alphanumeric Keypad b. Cursor (Directional) Control

Keys

c. Functions Keys d. Numeric

Keypad

Keyboards are of two (2) types: 1. Standard (Function

Keys are to the Left) and

2.

Enhanced (Function Keys are

to the Top).

Special

Function Keyboards are designed for specific

applications and replace the traditional keys

with special function keys. For example, fast food restaurants use

special function keyboards, which have keys representing items that they

sell. There may be a key therefore which

represents hot dog, another for ice cream, etc.

When pressed, these keys record the sale of the item they represent in a

much faster and efficient way that would be possible on a standard alphanumeric

keyboard.

Key-To-Disk Device

Data is entered through using a

Keyboard and is written to storage on a Magnetic Disk for processing.

Key-To-Tape Devices

Data is entered through using a

Keyboard and is written to storage on a Magnetic Tape for processing.

POINT AND DRAW DEVICES

Mouse

This is a standard device found on

today’s computer system. A small device

that when moved across the desktop a particular distance and direction, causes

the same movement of the cursor on the screen.

Cursor

This is a blinking underscore (-) that indicates

the location where the next character will be typed.

Uses of the Mouse

1.

To draw shape(s)

in graphics software 2. To position the cursor when editing

text

3. To select options from a menu or to

select icons

Pen-Based Input Devices (e.g. Light Pen)

These

Input Devices that accepts hand-written input by allowing uses to print

directly on a sensitised screen/pad using a pen-like stylus.

This is a pen-shaped device, held in the hand, which can be used to

write data into the computer for processing.

A cable is connected to the Light Pen and the other end is connected to

the computer (System Unit). The

Light Pen is used also to select options from a list of options on the Monitor

by pointing at the option required. The

Light Pen may also be used to produce drawing on the screen where the user can

draw in images into the computer on a sensitised pad such as the Digitizer (Pad).

Use of the Light Pen/Digitize Pen

1.

To choose from a list of

options on the screen by pointing on the screen at the option required

2.

To produce drawings on the

screen on a Digitizer (Pad)

Touch Screen/Touch Terminals

This is a sensitised display screen

that allows data to be inputted into the computer by touching the screen

surface with a finger or with the Light Pen.

The operator (user) makes selection by touching specified

parts of the screen. They are easy to be

used and are currently limited in use especially by persons who are not

familiar with a Keyboard. They are now

being used with Automated Teller Machine and with Kiosks.

Track Point

This

device looks like a miniature Joystick that is operated with the tip of the

finger but is used for the same purposes as the traditional mouse (pointing,

selecting and drawing). Because

of its size it is very popularly found on Laptop Computers, Notebooks, and is

normally positioned towards the middle of the Keyboard.

Track Ball

This is any inverted (up-side-down)

mouse where the ball is on top. For the

user to move the cursor or mouse pointer, the user rotates the ball with his

palm (or hand). Unlike the mouse,

the Track Ball stays stationery (one place) on the desktop. It is also a mice flipped on their back, but

instead of moving the mouse, the user move the ball directly. The Track Ball therefore does not need much

space, as a mouse needs.

Glide Pad/ Touch Pads

This is a device that has a touch

sensitive pad on which the user will glide his finger on it in order to move

the cursor on the screen. For clicking

and selecting objects, the user taps the touch sensitive pad. The Glide Pad is becoming popular used with

Lap Top Computers. Many Notebook

computers use this pointing device. The Glide

Pad/Touch Pad is a pressure sensitive device that responds to the

user’s finger movements over the pad’s surface.

Graphics/Digitizing Tablet

A tool used in CAD applications and

other graphics applications. It consists

of a grid on which designs and drawings can be entered. Most tablets are pressure sensitive, and the

user draws directly on the tablet using a special pen called a Stylus

also called a Pluck. This device

is used to design such things as cars, buildings, medical devices, robots,

etc. The Tablet has a flat surface on

which the user can draw using a special pen. While drawing the pressure on the surface is

detected and data about the position is sent to the computer, thus creating an

identical image on screen. This device

is primarily used to enter drawing and hand-written data and is very useful for

Graphic Artists, Architects, etc.

Mouse Pen

This device resembles a pen and is

rolled across the desktop like a mouse.

Pointing Stick

This is a small, stubby pointing

device that protrudes from the computer keyboard. To use this device, the user simple pushes

the stick in various directions. This

device is normally used with Lap Top Computers or portable Notebooks. The Joystick consists of a large vertical

lever that can be moved into any directions.

Although the Joystick is primarily a pointing device, it is most often

used to control the motion of an on-screen object such as in a computer game.

Personal Digital Assistant (PDA)

This is a small hand-held computer

that accepts input written on-screen with a stylus. A Stylus is a pen-shaped instrument used to

draw on a Graphics Tablet (Digitizer) or to input commands for

handwriting on a Personal Digital Assistant.

Most include built-in software for appointments, scheduling and

electronic mail. Also may be called Palmtop

Computer.

GAMING DEVICES

Joystick

This is a device that is used to

control movements of objects on the screen by shifting of a small lever. The Joystick can be made to produce faster

movement of the cursor on the screen.

The Joystick is mainly used to with video games.

SENSORY INPUT DEVICES

Sensor

This is a device that collects data

directly from the environment for input into the computer.

Smart Cards

These are devices being used to

collect sub-way and buses fares electronically and have become popular

alternatives to coins in public telephone booths.

SOURCE DATA AUTOAMTION DEVICES

Source Data Entry Automation

This is an advance form of data

input technology that generates machine-readable data at their point of

origin. Examples of these technologies

are Optical Character Recognition, Magnetic Ink Character Recognition, Digitizers

and Voice Input Devices. This is the

process of capturing data at its source, eliminating the need to file paper

documents or to record the day by keying it into the computer manually. The result is lower cost of operations and

few errors made during the data input stage.

Image Processing Systems are now being used to file

incoming paper documents electronically.

The documents are now being scanned and the images are being stored on

the computer, where it is easier and faster to retrieve them.

Document Reader

A Document Reader is a device that

is capable of reading data straight from the source document (document on which

the data is on. E.g. Paper) into the

computer for processing. Document Readers

come in three types namely Magnetic Ink Character Reader, Optical Mark Reader

and the Optical Character Reader.

MAGNETIC INK CHARACTER RECOGNITION

The Banking Industry developed one

of the earliest scanning systems in the 1950s to be used in their Cheque

Processing Applications. This is a form

of source data automation in which a Magnetic Ink Character Reader identifies

characters written in magnetic ink. This

technology is mainly used in cheque processing. The bank, branch, account number and cheque

numbers are encoded on the cheque before it is sent to the customer. After the customer has used the cheque and it

comes back to the bank, all that needs to be entered manually is the amount on

the cheque. MICR technology has

not been adopted by other industries because the characters used in the

encoding of data consist of only fourteen (14) symbols! The process by which the Magnetic Ink

Character Reader records data is known as Magnetic Ink Character Recognition.

MARK SENSE CHARACTER RECOGNITION/

OPTICAL CHARACTER RECOGNITION

This is a form of source data

automation in which optical scanning devices reads specifically designed data

off their source documents and translates the data into digital form for the

computer to process. The Optical Character Reader is

mainly used to recognize product codes from bar code on products found in

supermarkets, shops, pharmacies, etc.

Optical Character Recognition is sometimes used to sort mails in Post

Offices in the United States and other well-computerized countries in the

world. The process by which data is

entered using Optical Character Readers (Magnetic Ink Character Readers

& Optical Character Readers) is called Optical Character

Recognition.

Optical Mark Reader

This is a device that uses Optical

Character Recognition technology to mark multiple-choice examination papers. It is mainly used by Examination Councils

such as the Caribbean Examinations Council (CXC), Cambridge Examination

Council, etc. in the marking of their examination papers.

Types of data that can be read by a Document Reader

1. Marks made with some pencils 2. Hand

written characters

3. Printed Lines 4. Printed Characters -

numbers on hard mediums

5. Bar Code (Universal Product Code – UPC)

such as numbers on cheques or vouchers

Point of Sale (POS) Terminal

A computerized cash register type

terminal like that used in supermarket used to record data on sale of products

bought by customers. This device allows

management of supermarkets to keep a tab/check on the stock levels (how much

stock of particular goods is available for sale to consumers).

Bar Code Reader

This is a device used to read data

on bar codes into the computer for processing.

The Bar Code is a series of

thick and thin lines used to represent product information on products such as

the manufacturer, the type of product (name), the price, etc. Examples of Bar Code Readers are Scanners,

Point of Sale Terminals Light Wands, etc.

Scanner

This is a device that is designed to

scan and digitize graphical images into the computer for processing. This device allows data to be copied directly

from and entered into the computer in digital (digitize) form for

processing.

Types of Scanners

Label Scanner

This Scanner is used to read data on

price tags, shipping labels into the computer for processing.

Page Scanner

This is a Scanner that is capable of

reading alphanumeric characters into the computer from regular type written

pages.

Document Scanner

This Scanner is capable of reading

data from documents (on paper) of varying sizes (such as

receipts, utility bill payment slips, invoices, etc.) into the computer

for processing.

Continuous-Form Scanner

This Scanner is designed to read

data directly from continuous forms such a cash register tape into the computer

for processing.

Optical-Mark Scanner

This is a Scanner that can scan data

from specially prepared pre-printed forms such as multiple-choice forms into

the computer for processing. The

position of the Sense Marker

indicates a particular response of a character pre-setted into the computer

when marking and checks for the correct marks that were to be entered on the

special pre-printed forms. In other

words, the answers are already in the computer and the Sense Marker compares the answer in the computer with that which

the user entered on the form.

Digitizer (Pad)/Pads and Tablet

These are able to recognize neat

handwriting by means of a sensitive pad on which the source document can be

filled in by hand using ballpoint pen or the Light Pen. Those persons who are non-typists normally

use this input device. However, the handwriting

or drawing entered must be clear and neat if one is to use this device

effectively. This device is mainly used

in Computer Aided Drafting/Design

used to digitize maps, reproduce designs and drawings for plans for building,

computers, cars, etc.

SPEECH RECOGNITION DEVICES

Voice Data Entry Devices (Microphone)

A device which enables data to be

inputted into the computer system in the form of user recorded words, phrases,

music, alarms, etc.

Speech Recognition Systems

These systems are used to input

audio (sound) data into the computer. Existing Speech Recognition Systems are very

limited. There is the need for

specialised hardware (Speakers, Microphones) and the software

have to be trained to recognize the speech

patterns of

users. A good Speech Recognition System

never stops learning new words.

Typically, when a word is spoken, the system translates it into a

digital form for further processing. The

computer then tries to find a matching word in its vocabulary. If a match is found, the word is displayed on

the monitor or the command is executed.

Otherwise, the computer asks the user to repeat the word. Persons who routinely do dictations (e.g.

Doctors, Lawyers, Journalists) find Speech Recognition Systems very

useful. Other users who cannot use their

hands for data input (due to physical disability or due to the nature of the

job) also find these systems useful.

For example: a surgeon can, while

operating request information from the computer if he/she uses a Speech

Recognition System. Speech Recognition

Systems are being used by the Jamaica Public Service Company Limited, Cable and

Wireless Jamaica, National Water Commission, etc. in their Billing Interactive

System/Customer Care Centre.

VISION INPUT DEVICES

Vision Input System

A device that allows visual input of

data to a computer system for processing.

Example Digital Camera and Camera Recorder (CAMRECORDER).

Additional

Content:

·

Disadvantages and Advantages of

using Keyboards to enter data, use of mouse

·

Cumulative Trauma Disorder -

CTD

(Repetitive

Strain Injury -RSI)

·

Sound Cards

·

Use of Speech Recognition

Software, advantages and disadvantages of Speech Recognition Software

·

Continuous Speech Recognition

·

Video Cards

·

Web Cameras (Web Cams)

·

Source Data Automation,

Benefits, Limitations, use

·

Image Processing Systems

·

Biological Feedback Devices

·

Virtual Reality (use of

Virtual Reality Head helmet and glove)

·

Ergonomics Keyboard

·

Handwriting Recognition

Software – use, advantage, disadvantage

·

Track point

·

Toggle Key

·

Special Function Keyboards (used

by KFC, and other foods stores, used in Department Stores, Pharmacy, etc.)

·

Mouse Techniques (dragging,

double clicking, single clicking)

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