Input, Chapter 4 ITSC 1401, Intro to Computers Instructor: Glenda H. Easter

Objectives Describe the four types of input. List the characteristics of a keyboard. Identify various types of keyboards. Identify various types of pointing devices. Explain how a mouse works. Describe different mouse types.

Objectives (Continued) Explain how scanners and other reading devices work. Identify the purpose of a digital camera. Describe the various techniques used for audio and video input. Identify alternative input devices for physically and challenged users.

What Is Input? Input is any data or instructions you enter into the memory of a computer. There are four types of input: – Data – Program – Command – User Response

Four Types of Input Input Types – Data : A collection of unorganized facts – Program : A series of instructions that tells a computer how to perform a task. – Command: An instruction given to a computer program. – User response: An instruction you issue to the computer by replying to a question posed by a computer program

QWERTY Common Input Devices Keyboard Mouse Trackball Joystick Pen Input Light Pens Digitizing Tablets DVORAK

Inputting Data You can enter data into the computer in two methods. You can use keyboard, which is the traditional manner to input. Or you can use direct input, using a pointing device such as a mouse, scanner, or pen devices.

Input: Keyboard Input devices take data and programs people can read or understand and convert them to a form the computer can process. Keyboard Entry: This looks like a typewriter keyboard but has additional keys. With keyboard entry, users enter data through the keyboard from source documents.

Parts of a Keyboard Alphanumeric Keys Modifier Keys Numeric Keypad Function Keys Cursor-movement Keys Escape Key Special-purpose Keys

The Keyboard

Right click The mouse is a fairly intuitive input device. When it gets sluggish, turn it over and remove the cover plate. Carefully clean the ball and rollers. Left click A Pointing Device: A Mouse

Mouse operations Clicking Dragging Double-Clicking Pointing Devices clic k

Other Input Devices Touch-Sensitive Screens Scanning Devices – MICR – Bar Code Readers – OMR Voice Input Devices Video Digitizers

Additional Input Devices Soundcards Microphones & Speech Recognition Video Capture Cards Cameras Scanners Handheld scanner

Input: Direct Entry With this method, data is made into machine-readable form as it is entered. No keyboard is used. Data can be entered through scan devices which reflect lights on characters of data.

Direct Entry (Continued) Scanning Devices (Continued): Facsimile Transmission Machines ( FAX ): Transfers documents at electronic speeds.  Encodes image as a series of instructions representing black-and-white image areas.

Direct Entry (Continued) Scanning Devices ( Continued): Bar-Code Readers : Commonly used in grocery stores to read the UPC (Universal Produce Codes). Character and Mark Recognition Devices :  Magnetic-Ink Character Recognition (MICR) Reads bottom of checks

More Scanning Devices Scanning Devices (Continued): Character and Mark Recognition Devices ( Continued):  Optical-Mark Recognition (OMR) or mark sensing. These are the Scantrons that you purchase for use on tests.

More Scanning Devices Scanning Devices (Continued): Character and Mark Recognition Devices ( Continued):  Optical-Character Recognition ( OCR ): Reads special preprinted characters through a light source and changes them into machine- readable code. This is the type of scanner that is used in department stores.

Optical Scanners When a document is scanned, the results are stored in rows and columns of dots called a bitmap.

Additional Input Devices Biological feedback devices Chemical detectors Virtual reality programs use helmets to enable users to “move” through a simulated “world.”