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)

	Criado por Craig Thompson aproximadamente 10 anos atrás

All About Input Devices