Assignment Chapter 5 frm Mr tri Djoko Wahjono

ASSINGNMENT CHAPTER 5

Chapter Review Pages 290 – 291

Discovering Computer (“Living In the Digital World 2011”)

Lecture       :        Mr. Tri Djoko Wahjono

Student      :        Williem [1701309721]

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. It is a sequence of instructions, written to perform a specified task with a computer. 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 keyboard, 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.

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.

·         Keyboards for mobile computers and devices are 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. 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. Most desktop computer users have some type of:

·         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. 

·         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.

Windows users work with a mouse that has at least two buttons. For a right-handed user, the left button usually is the primary mouse button, and the right mouse button is the secondary mouse button. Left-handed people, however, can reverse the function of these buttons. There are many mouse operations, such as point, click, right-click, double-click, triple-click, drag, right-drag, rotate wheel, free-spin wheel, press wheel, tilt wheel, and press thumb button.

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.

·        A kiosk, which is a freestanding computer, usually includes a touch screen. For example, travelers use kiosk in airports to print tickets ordered online and in hotels for easy check in and check out.

·        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. The Microsoft Surface display also allows devices that are not digital, such as an everyday paintbrush, to be used as an input device. Restaurants, hotels, and other public locations provide Microsoft Surface tables to enhance guest services.

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 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, typically provides more functionality than a stylus, featuring electronic erasers and programmable buttons. Most digital pens, often simply called pens, are pressure-sensitive.

·         Computers and mobile devices often use handwriting recognition software, which is a program that translates the handwritten letters and symbols created on the screen with the stylus or pen into characters that the computer or device can process. To capture a handwritten signature, a user writes his or her name on a signature capture pad with a stylus or pen that is attached to the device. Software then transmits the signature via a cable connected to a port on the computer. Signature capture pads often include a magnetic stripe card reader and work with POS terminals.

·         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?

·         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.

·         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, which 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.

·         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.

·         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 allow the user to guide on-screen elements by moving a handheld 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.

7.      How does resolution affect the quality of a picture captured on a digital camera?

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 is the resolution, the better is the picture quality, but the more expensive is the camera. Digital camera resolutions range from approximately 4 million to more than 16 million pixels (MP). A camera with a 7.1 MP (7,100,000 pixels) resolution will provide a better quality than one with a 4 MP resolution. As a general rule, a 4 MP camera is fine for photos sent via e-mail or posted on the Web. For good quality printed photos, users should have a 5 MP camera for 4 3 6 inch photos, a 6 MP camera for 8 3 10 photos, and 7 MP or greater camera for larger size prints or more professional results.

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. Voice recognition programs recognize a vocabulary of preprogrammed words, which can range from two words to millions of words.

·         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.

·         A video conference

 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 microphone, speakers, and a video camera attached to or built in to a computer.

         9.      How do the various types of scanners and reading devices work?

·         An optical scanner, usually called a scanner, is a light-sensing input device that reads printed text and graphics and then translates the results into a form the computer can process. Four types of scanners are flatbed, pen, sheet-fed, and drum. A flatbed scanner works in a manner similar to a copy machine except it creates a file of the document in memory instead of a paper copy. Once you scan a document or picture, you can display the scanned object on the screen, modify its appearance, store it on a storage medium, print it, fax it, attach it to an e-mail message, include it in another document, or post it on a Web site or photo community for everyone to see.

·         Many scanners include OCR (optical character recognition) software, which can read and convert text documents into electronic files. OCR software is useful if you need to modify a document but do not have the original word processing file.

·         Businesses often use scanners for image processing, which consists of capturing, storing, analyzing, displaying, printing, and manipulating images. Image processing allows users to convert paper documents such as reports, memos, and procedure manuals into electronic images. Users distribute and publish these electronic documents on networks and the Internet.

·         Optical mark recognition (OMR) is a technology that reads hand-drawn marks such as small circles or rectangles. A person places these marks on a form, such as a test, survey, or questionnaire answer sheet. With a test, the OMR device first scans the answer key sheet to record correct answers based on patterns of light. The OMR device then scans the remaining documents and matches their patterns of light against the answer key sheet.

·         Bar Code Reader, also called a bar code scanner, is an optical reader that uses laser beams to read bar codes by using light patterns that pass through the bar code lines. A bar code is an identification code that consists either of a set of vertical lines and spaces of different widths or a two-dimensional pattern of dots, squares, and other images. The bar code represents data that identifies the manufacturer and the item. A newer type of bar code, called a 2-D bar code, can store much more data than the traditional linear bar code.

·         RFID (radio frequency identification) is a technology that uses radio signals to communicate with a tag placed in or attached to an object, an animal, or a person. RFID tags, which contain a memory chip and an antenna, are available in many shapes and sizes and sometimes are embedded in glass, labels, or cards. Some RFID tags are as small as a grain of sand; others are the size of a luggage tag. An RFID reader reads information on the tag via radio waves. RFID readers can be handheld devices or mounted in a stationary object such as a doorway.

10. What are various biometric devices?

A biometric device translates a personal characteristic into digital code that is compared with a digital code stored in the computer to identify an individual.

·         A fingerprint reader captures curves and indentations of a fingerprint.

·         A face recognition system captures a live face image and compares it with a stored image.

·         A hand geometry system measures the shape and size of a hand.

·         A voice verification system compares live speech with a stored voice pattern.

·         A signature verification system recognizes the shape of a signature.

·         An iris recognition system reads patterns in the iris of the eye. Retinal scanners scan patterns of blood vessels in the back of the retina.

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. The host computer processes the data and then, if necessary, sends information (output) back to the terminal. The host computer usually is a server or mainframe. The location in a retail or grocery store where a consumer pays for goods or services is the point of sale (POS). Most retail stores use a POS terminal to record purchases, process credit or debit cards, and update inventory. Many POS terminals handle credit card or debit card payments and thus also include an image stripe reader. Some have a fingerprint reader that is linked to a payment method such as a checking account or credit card. After swiping your card through the reader or reading your fingerprint, the POS terminal connects to a system that authenticates the purchase. Once the transaction is approved, the terminal prints a receipt for the customer.

·         An automated teller machine (ATM) is a self-service banking machine that connects to a host computer through a network. Banks place ATMs in convenient locations, including grocery stores, convenience stores, retail outlets, shopping malls, sports and concert venues, and gas stations, so that customers conveniently can access their bank accounts.

·         A DVD kiosk is a self-service DVD rental machine that connects to a host computer through a network. The DVD kiosks, some of which can hold more than 600 DVDs, are located nationwide at retail stores, fast-food restaurants, grocery stores, airports, and other convenient public locations.

12. What are alternative input devices for physically challenged users?

·         A key guard 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 key guard also guides a finger or pointing device so that a user presses only one key at a time. Keyboards with larger keys also are available.

·         Still another option is the on-screen keyboard, in which a graphic of a standard keyboard is displayed on the user’s screen.

·         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.