Assignment Chapter 5

Lecturer : Mr. Tri Djoko Wahjono, Ir., M.Sc

Name : Agatha Virgitia Darmawan

Student ID : 1701338122

1. What Is Input, and What Are the Differences among a Program, a Command, and a User Response?

•Input is any data or instructions entered into the memory of a computer, to provide or give something to the computer, in other words the state or act of a computer or a component of computer or relevant device being accepting something from the user or from a device or from a software either automatically or manually.

• A program is a series of related instructions that tells a computer what tasks to perform and how to perform them. When a programmer writes a program, he or she enters the program into the computer by using a keyboard, mouse, or other input device. The programmer then stores the program in a file that a user can execute (run). When a user runs a program, the computer loads the program from a storage medium into memory. Thus, a program is entered into a computer’s memory.

•Programs respond to commands that a user issues. A command is an instruction that causes a program to perform a specific action. Users issue commands by pressing keys on the key- board, clicking a mouse button, speaking into a microphone, or touching an area on a screen.

• A user response is an instruction a user issues by replying to a question displayed by a program. A response to the question instructs the program to perform certain actions. Assume the program asks the question, Is the time card correct? If you answer Yes, the program processes the time card. If you answer No, the program gives you the opportunity to modify the time card entries.

 2. What Keys Are Commonly Found on Desktop Computer Keyboards, and How Do Keyboards for Mobile Computers and Devices Differ from Desktop Computer Keyboards?

A keyboard is an input device that contains keys users press to enter data and instructions into a computer. Desktop computer keyboards typically have from 101 to 105 keys. All desktop computer keyboards have a typing area that includes the letters of the alphabet, numbers, punctuation marks, and other basic keys. Many desktop computer keyboards also have a numeric keypad on the right side of the keyboard. A keyboard also contains other keys that allow users to enter data and instructions into the computer.

Most of today’s desktop computer keyboards are enhanced keyboards. An enhanced keyboard has twelve or more function keys along the top; it also has two ctrl keys, two alt keys, and a set of arrow and additional keys between the typing area and the numeric keypad.

On notebook computers and some handheld computers, smart phones, and other mobile devices the keyboard is built in the top of the system unit. To fit in these mobile computers and devices, the keyboards usually are smaller and have fewer keys than desktop computer keyboards. A typical notebook computer key- board usually has only about 85 keys. To provide all of the functionality of a desktop computer keyboard, manufacturers design many of the keys to serve two or three purposes.

3. What Are Different Mouse Types, and How Do You Use a Mouse?

A mouse is a pointing device that fits under the palm of your hand comfortably. The mouse is the most widely used pointing device on desktop computers.

Optical mouse, which uses devices that emit and sense light to detect the mouse’s movement.

Some use optical sensors, and others use a laser. The latter, often referred to as a laser mouse, usually is more expensive than the former. You can place an optical mouse on nearly all types of flat surfaces. Some newer models combine both optical sensors and laser, enabling users to place the mouse on rougher surfaces such as carpeting and park benches. Further, some mouse devices are more sensitive than others for users requiring more precision such as graphic artists, engineers, or game players.

The mobile user who makes presentations may prefer a mouse that has additional buttons for running a slide show and controlling media, similar to a remote control. A newer type of mouse, called an air mouse, is a motion-sensing mouse that, in addition to the typical buttons, allows you to control objects, media players, and slide shows by moving the mouse in predetermined directions through the air.

A mouse connects to a computer in several ways. Many types connect with a cable that attaches to a USB port or a mouse port on the system unit. A wireless mouse, or cordless mouse, is a battery-powered device that transmits data using wireless technology, such as radio waves (Bluetooth) or infrared light waves (IrDA). Some users prefer a wireless mouse because it frees up desk space and eliminates the clutter of a cord.

As you move a mouse, the mouse pointer moves on the screen. You then press a mouse button (usually the left) to click objects. Some programs support mouse gestures, where users can per- form certain actions by holding a mouse button while moving the mouse in a particular pattern.

4. What Are the Various Types of Touch Screens, and How Does a Touch-Sensitive Pad Work?

A touch screen is a touch-sensitive display device. Touch screens that recognize multiple points of contact at the same time are known as multi-touch. Users can interact with touch screens by touching areas of the screen. Because touch screens require a lot of arm or hand movements, you do not enter large amounts of data using a touch screen. Instead, you touch words, pictures, numbers, letters, or locations identified on the screen. Some touch screens also respond to finger motions such as sliding your finger to drag an object or pinching your fingers to zoom in or out. The latest version of the Windows operating system provides increased support for computers with touch screens. Support for touch screen makes it easier for users to interact with the operating system.

A kiosk, which is a freestanding computer, usually includes a touch screen. For example, travelers use kiosks in airports to print tickets ordered online and in hotels for easy check in and check out. To allow easy access of your bank account from a car, many ATMs have touch screens.

A recently developed touch screen, called Microsoft Surface, is a 30-inch tabletop display that allows one or more people to interact with the screen using their fingers or hands.

Portable media players that do not have touch screens typically have a touch-sensitive pad, which is an input device that enables users to scroll through and play music, view pictures, watch videos or movies, adjust volume, and/or customize settings. Touch- sensitive pads typically contain buttons and/ or wheels that are operated with a thumb or finger. For example, users rotate a Click Wheel to browse through the portable media player’s song, picture, or movie lists and press the Click Wheel’s buttons to play or pause media, display a menu, and perform other actions.

 5. What Are the Various Types of Pen Input, and What Are Other Types of Input for Smart Phones?

With pen input, you touch a stylus or digital pen on a flat surface, such as a screen on a monitor or mobile device, a signature capture pad, or a graphics tablet, to write, draw, or make selections. A stylus is a small metal or plastic device that looks like a tiny ink pen but uses pressure instead of ink. A digital pen, which is slightly larger than a stylus, features electronic erasers and programmable buttons. Handwriting recognition software is a program that translates handwritten letters and symbols into characters a computer or mobile device can process. A signature capture pad captures signatures written with a stylus or pen attached to a device. Some smart phones have digital cameras that have touch-sensitive pads. Others have a portable keyboard or optical keyboard built in.

 6. What Are the Purposes of Gamepads, Joysticks and Wheels, Light Guns, Dance Pads, and Motion-Sensing Game Controllers?

Gamepads

A gamepad, which is held with both hands, controls the movement and actions of players or objects in video games or computer games. On the gamepad, users press buttons with their thumbs or move sticks in various directions to trigger events. Gamepads communicate with a game console or a personal computer via wired or wireless technology.

Joysticks and Wheels

Users running game software or flight and driving simulation software often use a joystick or wheel to control an airplane, vehicle, or player. A joystick is a handheld vertical lever mounted on a base. You move the lever in different directions to control the actions of the simulated vehicle or player. The lever usually includes buttons, called triggers, that you press to initiate certain events. Some joysticks also have additional buttons you press to perform other actions. A wheel is a steering-wheel-type input device. Users turn the wheel to simulate driving a car, truck, or other vehicle. Most wheels also include foot pedals for acceleration and braking actions. Joysticks and wheels typically attach via a cable to a personal computer or game console.

Light Guns

A light gun is used to shoot targets and moving objects after you pull the trigger on the weapon. Instead of emitting light, most light guns work by detecting light. When the user pulls the trigger, the screen uses one of several techniques to send light, which is received by a receptor in the barrel of the gun. Light guns typically attach via a cable to a game console or personal computer.

Dance Pads

A dance pad is a flat electronic device divided into panels that users press with their feet in response to instructions from a music video game. These games test the user’s ability to step on the correct panel at the correct time, following a pattern that is synchronized with the rhythm or beat of a song. Dance pads communicate with a game console or a personal computer via wired or wireless technology.

Motion-Sensing Game Controllers

 Motion-sensing game controllers allow the user to guide on-screen elements by moving a hand- held input device in predetermined directions through the air. Some are sold with a particular type of game; others are general purpose. Sports games, for example, use motion-sensing game controllers, such as baseball bats and golf clubs, as their input device. These types of controllers communicate with a game console or a personal computer via wired or wireless technology. A popular general-purpose, motion-sensing game controller is Nintendo’s Wii Remote. Shaped like a television remote control and operated with one hand, the Wii Remote is a motion-sensing input device that uses Bluetooth wireless technology to communicate with the Wii game console. Users point the Wii Remote in different directions and rotate it to control on-screen players, vehicles, and other objects.

Other Game Controllers

Other popular game controllers include musical instruments and balance boards. Controllers that resemble musical instruments, such as guitars, drums, and keyboards, work with music video games that enable game players to create sounds and music by playing the instrument. Fitness games often communicate with a balance board, which is shaped like a weight scale and contains sensors that measure a game player’s balance and weight .Musical instrument and balance board controllers communicate with game consoles via wired or wireless technology.

7. How Does Resolution Affect the Quality of a Picture Captured on a Digital Camera?

A digital camera allows users to take pictures and store the photo- graphed images digitally. One factor that affects the quality of digital camera photos is its resolution. Resolution is the number of horizontal and vertical pixels in a display device. A pixel (short for picture element) is the smallest element in an electronic image. The greater the number of pixels the camera uses to capture a picture, the better the quality of the picture. Thus, the higher the resolution, the better the picture quality, but the more expensive the camera.

Many digital cameras provide a means to adjust the ppi to the desired resolution. With a lower ppi, you can capture and store more images in the camera. For example, a camera set at 1280 3 960 ppi might capture and store 61 photos, if it has sufficient storage capacity. The number of photos may reduce to 24 on the same camera set at 2592 3 1944 ppi, because each photo consumes more storage space.

8. How Are Voice Recognition, Web Cams, and Video Conferencing Used?

Voice recognition, also called speech recognition, is the computer’s capability of distinguishing spoken words. Other popular voice recognition programs for personal computers include IBM ViaVoice and Dragon Naturally Speaking. Voice recognition programs recognize a vocabulary of preprogrammed words, which can range from two words to millions of words. The auto- mated telephone system at your bank may ask you to answer questions by speaking the words Yes or No into the telephone. A voice recognition program on your computer, by contrast, may recognize up to two million words. Some cur- rent cell phones and other mobile devices allow you to store voice commands such as “Call Tom at home.” Operating systems, such as Windows, also include voice recognition capabilities. Keep in mind that the best voice recognition pro- grams are 90 to 95 percent accurate, which means the software may interpret as many as one in ten words incorrectly.

A Web cam, also called a PC video camera, is a type of digital video camera that enables a home or small business user to capture video and still images, send e-mail messages with video attachments, add live images to instant messages, broadcast live images over the Internet, and make video telephone calls. During a video telephone call, both parties see each other as they communicate over the Internet. The cost of Web cams usually is less than $100.

A video conference is a meeting between two or more geographically separated people who use a network or the Internet to transmit audio and video data. To participate in a video conference using a computer, you need video conferencing software or use a video conferencing Web application, along with a micro- phone, speakers, and a video camera attached to or built in to a computer. Examples of video conferencing software include CUworld, Live Meeting, and WebEx. As you speak, members of the meeting hear your voice on their speakers. Any image in front of the video camera, such as a person’s face, appears in a window on each participant’s screen. A whiteboard is another window on the screen that displays notes and drawings simultaneously on all participants’ screens. This window pro- vides multiple users with an area on which they can write or draw.

9. How Do the Various Types of Scanners and Reading Devices Work?

A scanner, or optical scanner, is a light-sensing input device that reads printed text and graphics and translates the results into a form the computer can process. A flatbed scanner works in a manner similar to a copy machine except it creates a file of the document. An optical reader uses a light source to read characters, marks, and codes and converts them into digital data that a computer can process. Optical character recognition (OCR) reads characters from ordinary documents. Optical mark recognition (OMR) reads hand-drawn marks such as small circles or rectangles. A bar code reader, or bar code scanner, is an optical reader that uses laser beams to read a bar code, or identification code. RFID (radio frequency identification) uses radio signals to communicate with an embedded tag placed in or attached to an object, an animal, or a person. A magnetic stripe card reader, also called a magstripe reader, reads the magnetic stripe on the back of credit cards and other similar cards. MICR (magnetic-ink character recognition) reads text printed with magnetized ink.

10. What Are Various Biometric Devices?

Biometrics is the technology of authenticating a person’s identity by verifying a personal characteristic. Biometric devices grant users access to programs, systems, or rooms by analyzing some biometric identifier. A biometric identifier is a physiological (related to physical or chemical activities in the body) or behavioral characteristic. Examples include fingerprints, hand geometry, facial features, voice, signatures, and eye patterns.

The most widely used biometric device today is a fingerprint reader. A fingerprint reader, or scanner, captures curves and indentations of a fingerprint.

A face recognition system captures a live face image and compares it with a stored image to determine if the person is a legitimate user. Some buildings use face recognition systems to secure access to rooms.

Biometric devices measure the shape and size of a person’s hand using a hand geometry system. Because their cost is more than $1,000, larger companies use these systems as time and attendance devices or as security devices.

A voice verification system compares a person’s live speech with their stored voice pattern. Larger organizations sometimes use voice verification systems as time and attendance devices.

A signature verification system recognizes the shape of your handwritten signature, as well as measures the pressure exerted and the motion used to write the signature. Signature verification systems use a specialized pen and tablet. High security areas use iris recognition systems.

The camera in an iris recognition  system uses iris recognition technology to read patterns in the iris of the eye.

11. How Do POS Terminals, Automated Teller Machines, and DVD Kiosks Work?

A terminal is a computer,  usually with limited processing power, that enables users to send data to and/or receive information from a host computer. POS terminals, ATMs, and DVD kiosks are special-purpose terminals. A POS (point-of-sale) terminal records purchases, processes credit or debit cards, and updates inventory. An automated teller machine (ATM) is a self-service banking machine that connects to a host computer through a network. A DVD kiosk is a self-service DVD rental machine that connects to a host computer through a network.

12. What Are Alternative Input Devices for Physically Challenged Users?

The ever-increasing presence of computers in everyone’s lives has generated an awareness of the need to address computing requirements for those who have or may develop physical limitations. The Americans with Disabilities Act (ADA) requires any company with 15 or more employees to make reasonable attempts to accommodate the needs of physically challenged workers. Besides voice recognition, which is ideal for blind or visually impaired users, several other input devices are available. A keyguard is a metal or plastic plate placed over the keyboard that allows users to rest their hands on the keyboard without accidentally pressing any keys. A keyguard also guides a finger or pointing device so that a user presses only one key at a time. Keyboards with larger keys also are avail- able. Still another option is the on-screen keyboard, in which a graphic of a standard keyboard is displayed on the user’s screen. Various pointing devices are available for users with motor disabilities. Small trackballs that the user controls with a thumb or one finger can be attached to a table, mounted to a wheelchair, or held in the user’s hand. Another option for people with limited hand movement is a head-mounted pointer to control the pointer or insertion point. To simulate the functions of a mouse button, a user works with switches that control the pointer. The switch might be a hand pad, a foot pedal, a receptor that detects facial motions, or a pneumatic instrument controlled by puffs of air. Two exciting developments in this area are gesture recognition and computerized implant devices. Both in the prototype stage, they attempt to provide users with a natural computer interface. With gesture recognition, the computer will detect human motions. Computers with gesture recognition capability have the potential to recognize sign language, read lips, track facial movements, or follow eye gazes. For paralyzed or speech impaired individuals, a doctor will implant a computerized device into the brain. This device will contain a transmitter. As the user thinks thoughts, the transmitter will send signals to the computer.