Make your own free website on






   Input is any data or instructions you enter into the memory of a computer.  Once input is in memory, the CPU can access it and process the input into output.  Four types of input are data, programs, commands, and user responses:

i)      Data is a collection of unorganized facts that can include words, numbers, pictures, sounds, and videos.  A computer manipulates and process data into information, which is useful.  Although technically speaking, a single item of data should be called a datum; the term data commonly is used and accepted as both the singular and plural form of the word.

ii)      A program is a series of instructions that tells a computer how to perform the tasks necessary to process data into information.  Programs are kept on storage media such as a floppy disk, hard disk, CD-ROM, or DVD-ROM. Programs respond to commands issued by a user.

iii)      A command is an instruction given to a computer program.  Typing keywords or pressing special keys on the keyboard can issue commands.  A keyword is a specific word, phrase, or code that a program understands as an instruction. Some keyboards include keys that send a command to a program when you press them.

Instead of requiring you to remember keyword or special keys, many programs allow you to issue commands by selecting menu choices or graphical objects.  For example, programs that are menu-driven provide menus as a means of entering commands.  Today, most programs have a graphical user interface that use icons, buttons, and other graphical objects to issue commands.  Of all of these methods, a graphical user interface is the user-friendliest way to issue commands.

A user response is an instruction you issue to the computer by replying to a question posed by a computer program, such as do you want to save the change you made? Based on your response, the program performs certain actions.  For example, if you answer, yes, to this question, the program saves your changed file on a storage device.



An input device is any hardware component that allows you to enter data, programs, commands, and user responses into a computer.  Input devices include the keyboard, pointing devices, scanners and reading devices, digital cameras, audio and video input devices for physically challenged user.  Each of these input devices is discussed in the following pages.



Many input devices use an electronic pen instead of keyboard or mouse for input. Some of there devices require you to point to onscreen objects with the pen ;others allow you to input data using drawings, handwriting, and other symbols that are written with the pen on a surface….



A light pen is a handheld input device that contains a light source or can detect light. Some light pens require a specially designed monitor, while others work with a standard monitor. Instead of touching the screen with your finger to interact with the computer, you press the light pen against the surface of the screen or point the light pen at the screen and then press a button on the pen. Light pens are used is limited such as in the health –care field or when a wide variety of people use the application, such as electronic voting. Readers should also note that you could create a very cost effective electronic whiteboard using a Light Pen combined with a CRT-Type rear projection system.

As well, mounting a large (digitizing tablet) on the wall. For example, and projecting into it, is another alternative approach to prototyping a digital whiteboard.  


Many handheld computers also allow inputting data using an electronic pen (also called a stylus) looks like a ballpoint pen but uses an electronic head instead of ink. Pen computers use handwriting recognition software that translates the letters and symbols used in handwriting into character data that the computers can use. Although most handwriting recognition soft hare recognizes printed letters and can be trained to distinguish writing styles, pen –computing technology continues to be refined.  


A graphics tablet, also called a digitizer or digitizing tables, consists of a flat, rectangular, electronic plastic bond used to input drawings, sketches, or other graphical data. Each location on the graphical tablet corresponds to a specific location on the screen. When you draw on the tablet with either an electronic pen or a puck, the tablet detects and converts the movements into digital signals that are sent into the computer. A puck is a device that looks similar to a mouse, except that is has a window with cross hairs so the user can see though to the tablet. Users with precise pointing requirements such as mapmakers and architects use a puck.




                      Waco Graph ire Bronze 4 x 5 USB Tablet.              Logitech 10 Personal Digital Pen 


                           Waco Grapier Ruby 4 x 5   Tablet                          Waco Intuits 2 4 x5



One interesting new feature of Tablet PC is the pen input system. All Tablet PC computers have a digitizer beneath the screen that accepts pen input. This new input mechanism requires you to think about how to build applications specifically for tablet PC .The Tablet PC platform API will help you do this.

The Tablet PC platform can be divided into three distinct areas:

Ink collection (objects that are used to collect ink from the digitizer).

Ink data management (objects that are used to manage the collected ink)

Ink recognition (objects that are used to convert the collected ink into other types of data, such as text).

The following image shows, at high level, haw the Ink Collection API (Pen API) ,Ink Data Management API (Ink API) , and Ink Recognition API (Recognition API) work together in the Tablet PC platform.




Some users opt for alternative pointing devices other than a mouse, such as trackball. Where a mechanical mouse has ball mechanism on the bottom, a trackball is a station- aryl pointing device with a ball mechanism on its top .The ball mechanism in a larger trackball is about the size of a Ping-Pong ball; some mouse devices also have a small trackball about the size of a marble.

To move the pointer using a trackball, you rotate the ball mechanism with your thumb, fingers, or the palm of your hand. Around the ball mechanism, usually a trackball also has one more buttons that work just like mouse buttons.

Although it shares characteristic with a mouse, a trackball is not as accurate as a mouse .A trackballs ball mechanism also requires frequent cleaning because it picks up oils from your fingers and dust from the environment. If you have limited desk space, however, a trackball is a good alternative to a mouse because you do not have to move the entire device pointer, has advantage that cursor stays in position when device put down.






          Logitech Cordless Trackman Wheel Mouse                4 D Scroll Track Finger  Mouse                           



        Qtronix Libra 90 M/Net Trackball                              Trackman Opt Wheel




Digital camera allows you to take pictures and store the photographed images digitally instead of on traditional film. With some digital cameras, you down load, or transfer a copy of, the stored pictures to your computer by connecting a cable between the digital camera and your computer and using special software included with the camera. With other digital cameras, the pictures are stored directly on a floppy disk or on PC card.

You then copy the pictures to your computer by inserting the floppy disk into a disk drive or the PC Card into a PC Card slot. Once the pictures are on your computer, they can be edited with photo-editing software, printed, faxed, sent via electronic mail, included in another document, or posted to a Web site for everyone to see.

The three basic types of digital cameras are studio cameras, field cameras, and point-and shoot- cameras. The most expensive and highest quality of the three, studio camera

         i)      is a stationary camera used for professional studio work.

       ii)      Often used by photojournalist, a field camera is a portable camera that has many lenses and other attachment; like the studio camera, a field camera can be quite expensive

      iii)      A point-and-shoot camera is more affordable and lightweight and provides acceptable quality photographic images for the home or small business user..

      iv)      You can use a point-and-shoot camera to add pictures to personalized greeting cards, a computerized photo album, a family newsletter, certificates, awards, or your own web site.

        v)      The point-and-shoot camera also is ideal for mobile users such as real estate agents, insurance agents, and general contractors.

Ranging from 640x 480 to 1024x 960. Other features of digital cameras are As with a scanner, the quality of a digital camera is measured by the number of bits it stores in a dot and the number of dots per inch, or resolution. The higher each number, the better quality, but the more expensive the camera. Most of today’s point-and-shoot digital camera are at least 24-bit with a resolution discussed in chapter 13.  




The mouse is the most widely used pointing device because it takes full advantage of a graphical user interface. Designer to fit comfortably under the palm of your hand, a mouse is an input device that is used to control the movement of the pointer on the screen and to make selections from the screen. She top of the mouse has one to four buttons. Some also have a small wheel. The bottom of a mouse is flat and contains a multidirectional mechanism and usually a small ball. The mouse often rests on a mouse pad, which usually is a rectangular rubber or foam pad that provides better traction for the mouse than the top of a desk. The mouse pad also protects the ball mechanism from a build up of dust and dirt, which could cause it to malfunction.






As you move the mouse across a flat surface such as a desktop, the pointer on the screen also moves. For example, when you move the mouse to the right, the pointer moves right on the screen. When you move the mouse to the left, the pointer moves left on the screen, and so on. If you have never worked with a mouse, you might find it a little awkward at first, with a little practice, however, you will discover that a mouse is quite easy to use.

Generally, you use the mouse to move the pointer on the screen to an object such as a button, a menu, an icon, a link, or text and then press one of the mouse buttons to perform a certain action on that object. In windows98, for example, if you point to the start button on the taskbar and then press, or click, the primary mouse button, the start menu displays on the screen.

For a right-handed user, the primary mouse button typically is the left button, and the secondary mouse button typically is the right mouse button. The function of these buttons, however, can be reversed to accommodate left-handed people.

You can perform other operations using the mouse in addition to clicking. These operations include point, right-click, double-click, drag, and right-drag. Some mouse devices also have a wheel located between two buttons that can be used with certain programs. You often rotate or press the wheel to move text and objects on the screen. The function of the mouse buttons and the wheel varies depending on the program. Some programs also use keys in combination with the mouse to perform certain actions.



A mouse that has a rubber or metal ball on its underside is called a mechanical mouse. When the ball rolls in a certain direction, electronic circuits in the mouse translate the movement of the mouse into signals that are sent to the computer. Another type of mouse, called an optical mouse, has no moving mechanical parts inside; instead it uses devices that emit light to detect the mouse’s movement.







Scanners have become an important part of the home office over the last few years. Scanner technology is everywhere and used in many ways:

Ø      Flatbed scanners, also called desktop scanners, are the most versatile and commonly used scanners. In fact, this article will focus on the technology as it relates to flatbed scanners.

Ø      Sheet-fed scanners are similar to flatbed scanners except the document is moved and the scan head is immobile. A sheet-fed scanner looks a lot like a small portable printer.

Ø      Handheld scanners use the same basic technology as a flatbed scanner, but rely on the user to move them instead of a motorized belt. This type of scanner typically does not provide good image quality. However, it can be useful for quickly capturing text.

Ø      Drum scanners are used by the publishing industry to capture incredibly detailed images. They use a technology called a photo multiplier tube (PMT). In PMT, the document to be scanned is mounted on a glass cylinder. At the center of the cylinder is a sensor that splits light bounced from the document into three beams. Each beam is sent through a color filter into a photo multiplier tube where the light is changed into an electrical signal.


Microtel's Scan maker flatbed scanner



A standard computer keyboard sometimes is called a QWERTY keyboard because of the layout of its typing area. Pronounced KWER-tee, this keyboard layout is named after the first six leftmost letters on the top alphabetic line of the keyboard. Because of the way the keys are organized, a QWERTY keyboard might limit your typing speed. A keyboard with an alternative layout was designed to improve typing speed. Called the Dvorak keyboard (pronounced de-vor-zhak),

         i)      This type of keyboard places the most frequently typed letters in the middle of the typing area.

       ii)      Despite the more logical design of the Dvorak keyboard, the QWERTY keyboard is more widely used.

Most of today’s desktop computer keyboards are an enhanced keyboard, which means they have twelve function keys along the top, two CTRL keys, two ALT keys, and a set of arrow and additional keys between the typing area and the numeric keypad.

Although most keyboard attach to a serial port on the system unit via a cable, some keyboard-called wireless keyboard- transmit data via infrared light waves. For a wireless keyboard to transmit signals to a computer, both the computer and the wireless keyboard must have and IrDA port. These IrDA ports must be aligned so that nothing obstructs the path of the infrared light wave. On laptops and many handheld computers, the keyboard is built into the top of the system unit. To fit in this smaller computer, the keyboards usually are smaller and have fewer keys. A typical laptop computer keyboard, for example, has only 85 keys, compared to the 105 keys on most desktop computer keyboard. To provide all of the functionality of a desktop computer keyboard, manufacturer design many of the keys to serve two or three different purpose.

Regardless of size, most keyboards have a rectangular shape with the keys aligned in rows. Users who spend a significant amount of time typing on thee keyboards sometimes experience repetitive strain injuries of their writs. For these reason, some manufacturers have redesigned their keyboards to minimize the chance of these types of workplaces injuries. Keyboard such as these are called ergonomic is to incorporate comfort, efficiency, and safety into the design of items in the workplace.




1)      USB Provides compatibility with legacy

Free Systems.

The company is in its fourth quarter of shipping USB devices. As computer companies continue to stand-arise on legacy- free systems, Telex will continue to lead the way with innovate USB microphones are perfect for legacy--free systems like Apple’s iBook or Compaq iPac.

2)      USB delivers highest- quality digital input and Easy set up.

    Ø The result is more accurate speech

    Ø      Recognition and higher voice quality. This innovative desktop microphone.

    Ø      Works with any USB- equipped PC running Microphone Windows (TM) 98 or

                     Apple) IBook(TM) systems running Mac OS 9. 0 4.

    Ø      Because there is no sound card to configure, you simply plug it in.

    Ø      This desktop microphone provides high – quality audio input without a headset.

    Ø      Now you can use voice application without being tethered to your computer by a             


3)      Acoustic Directional Processing (TM) technology cancels background noise.

    Ø      That consistent audio performance is critical for accurate result with voice application.

    Ø      Why Telex has used its more than 60 years of experience in the audio industry to the 

                     unique microphone structure that allows destructive.  

    Ø      Interference to cancel background noise and focus audio reception on the user’s voice.

    Ø      The Telex M-560 provides speech recognition up to two feet away in most office            

    Ø      Effective range is even further for other application. And its price                 

               performance Cant’ be beat.

4)      Ideal for voice application.

    Ø      The microphone is ideal for all voice application, including internet phone

                and chat, video conferencing or editing, language labs, voice command

                and control, and speech dictation.




Users running game software such as a driving of flight simulator may prefer to use a joystick as their pointing device. A joystick is a vertical lever mounted on a base (Figure 4-18). You move the lever in different direction to control the actions of a vehicle or player. The lever usually includes buttons called triggers that you can press to activate certain events. Some joysticks also have additional buttons that you can set to perform other actions.  

Advanced Gravy’s PC Game Peripherals Page

Links to their line of game accessories, including several joysticks.

Avb Joystick Products

Home page of AVB Co., manufacturer of joysticks, force feedback steering wheels, joy pads, and other game control devices.

CH Joystick Products

Offers links to a full line of PC, Macintosh, and 3DO systems joysticks, throttles, F-16 sticks, rudder pedals, flight yokes, game cards, and trackballs, all manufactured and designed by CH products.

Faqs On Joysticks

Provides information on calibrating joysticks, along with programming and connecting this device.

Joystick Product From HOT CD

Describe the Demon Gann product; wh9ick is a joystick type of device (though shaped like a gun), to use in action games like Doom, Heretic, and other 3D action games.

Mac Game Product Page

This page, from Sun remarketing, provides photographs and descriptions of several mice, trackballs, Mac ALLY joystick, and queue pads specifically for the Macintosh.

Microsoft Sidewinder 3D Pro Joysticks Review

This product review contains a functional review of Microsoft’s Sidewinder 3D Pro joystick




Computer gamers have been filling the simulated skies and virtual roadways, enjoying the growing number of adventure games and flight simulators available on the market. Joystick manufacturers have kept pace with the explosion of software, providing a variety of input devices designed to make your armchair experiences closer to the reality of maneuvering a jet fighter or racecar.

Many of the new joysticks are programmable, providing greater control and customization as you play your favorite games. The serious joystick user certainly needs more control than just up/down and left/right; even the occasional gamer knows that game performance depends upon fine-tuning your joystick settings. Windows 95 provides a joystick configuration feature among its Control Panel icons. This feature lets you define property settings for multiple joystick devices, making sure they’re properly calibrated before starting your game.

Just connect the joystick device you want to calibrate to your computer. In Win95, left-click the Start button, and select Settings. From the Settings menu, left-click Control Panel. From within Control Panel, double left-click the Joystick icon. The Joystick properties window will open. This window lets you save the property settings for any joysticks, flight yokes, or game pads you’ll be using. First, select the Current Joystick by left-clicking the down arrow and then left-clicking the appropriate number (1 through 16).

Move down to the Joystick Configuration section in the window. If the current joystick has not been calibrated, “None” will be displayed. If it has been....