Hardware

1. Hardware Magister Teknik Elektro Pertemuan V 2008

2. Input & Output • Input Hardware • Devices that translate data into a form the computer can process--may be divided into three categories: keyboards, pointing devices, and source-data entry devices. • The people-readable form of the data may be words, but the computer-readable form consists of binary 0s and 1s, or off and on electrical signals. • Output Hardware • consists of devices that translate information processed by the computer into a form that humans can understand. • The computer-processed information consists of 0s and 1s, which need to be translated into words, numbers, sounds, and pictures. 38 slides

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4. Keyboards • Two categories of keyboards, devices that convert characters into electrical signals readable by the processor. • The first is the traditional computer keyboard, which has all the keys of a typewriter plus some that are unique. • The second category, specialty keyboards and terminals, includes three types of terminals: • (1) A dumb terminal has screen and keyboard and can input and output but not process data. Why it's important: Dumb terminals are used, for example, by airline reservations clerks to access a mainframe computer containing flight information. • (2) An intelligent terminal has screen, keyboard, and its own processor and memory. One example is the automated teller machine (ATM), the self-service banking machine. Another is the point-of-sale (POS) terminal, used to record purchases in a store. • Why it's important: Such a terminal can perform some functions independent of any mainframe to which it is linked. Examples include the automated teller machine (ATM), a self-service banking machine connected through a telephone network to a central computer, and the point-of-sale (POS) terminal, used to record purchases at a store's customer checkout counter. Recently, many intelligent terminals have been replaced by personal computers. 38 slides

5. Keyboard 38 slides Caption: Dumb terminals used by airline reservations clerks

6. (3) An internet terminal • Terminal that provides access to the Internet. There are several variants of Internet terminal: (1) the set top box or web terminal, which displays web pages on a TV set; (2) the network computer, a cheap, stripped-down computer that connects people to networks; (3) the online game player, which not only lets you play games but also connects to the Internet; (4) the full-blown PC/TV(or TV/PC), which merges the personal computer with the television set; and (5) the wireless pocket PC or personal digital assistant (PDA), a handheld computer with a tiny keyboard that can do two-way wireless messaging. • Why it's important:In the near future, most likely, Internet terminals will be everywhere. • Related Industry: WebTV is a well-known example of a web terminal. There are two components to WebTV: the set top box, and the subscription-based online service. Microsoft Corporation purchased the latter, known as WebTV Networks in 1997. It is now known as MSN TV. Philips Magnavox manufactures the set top boxes. 38 slides

7. Pointing Devices • Devices that control the cursor or pointer on a screen • They include the mouse and its variants, the touch screen, and various forms of pen input. • (1) The mouse, which directs a pointer on the display screen, is moved on the desktop. Variants are: • The trackball, Movable ball, mounted on top of a stationary device, that can be rotated using your fingers or palm. It looks like the mouse turned upside down. Instead of moving the mouse around on the desktop, you move the trackball with the tips of your fingers. Why it's important:Trackballs require less space to use than does a mouse. • Pointing stick, which protrudes from the keyboard; and the touchpad, a surface over which you move your finger. Why it's important:Pointing sticks are used principally in videogames, in computer-aided design systems, and in robots. 38 slides

8. Trackball Touchpad 38 slides

9. (2) The touch screen is a display screen that is sensitive to touch. • You find touch screens in kiosks, ATMs, airport tourist directories, hotel TV screens (for guest checkout), and cam-pus information kiosks making available everything from lists of coming events to (with proper ID and personal code) student financial-aid records and grades. • (3) Devices for pen input include pen-based computer systems, in which users write with a pen-like stylus on a screen; light pens, light-sensitive penlike devices; and digitizers, which convert drawings to digital data--one example is the digitizing tablet. • Pen computers use handwriting recognition software that translates handwritten characters made by the stylus into data that is usable by the computer. • Why it's important: Many handheld computers and PDAs have pen input, as do digital notebooks. 38 slides

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11. Digitizing Tablet • One form of digitizer; an electronic plastic board on which each specific location corresponds to a location on the screen. When you use a puck, the tablet converts your movements into digital signals that are input to the computer. • Why it's important: Digitizing tablets are often used to make maps and engineering drawings, as well as to trace drawings. 38 slides

12. Source Data-Entry Devices • Create machine-readable data on magnetic media or paper or feed it directly into the computer's processor. • As well as various scanning devices--imaging systems, bar-code readers, mark- and character-recognition devices, and fax machines--they include audio-input devices, video input, photographic input (digital cameras), voice-recognition systems, sensors, radio-frequency identification devices, and human-biology input devices. 38 slides

13. (1) Scanners use laser beams and reflected light to translate images of text, drawings, and photographs into digital form. • One type is an imaging system, which converts text, drawings, and photos into digital form that can be processed or stored in a computer system. This has led to the new industry of electronic imaging, the integration of separate images using scanners. • Another scanning device is the bar code reader, which reads the zebra-striped barcodes on products to translate them into digital code. • Magnetic-ink character recognition (MICR) reads check numbers (Scanning technology that reads magnetized-ink characters printed at the bottom of checks and converts them to digital form. Why it's important: MICR technology is used by banks to sort checks.); • optical mark recognition (OMR) reads pencil marks (Scanning technology that reads pencil marks and converts them into computer-usable form. Why it's important: OMR technology is used to read the College Board Scholastic Aptitude Test (SAT) and the Graduate Record Examination (GRE). ); • optical character recognition (OCR) reads preprinted characters, such as those on store price tags. Scanning technology that reads special preprinted characters in a particular font (typeface design) and converts them to digital code.Why it's important:OCR characters appear on utility bills and price tags on department-store merchandise. 38 slides

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15. Caption: Optical characters and an OCR device 38 slides

16. The fax machine, the last type of scanner, reads images and sends them over phone lines. • Dedicated fax machines only send and receive fax documents; Specialized device that does nothing except send and receive fax documents. Why it's important:Fax machines permit the transmission of text and graphic data over telephone lines quickly and inexpensively. • fax modems are modems with fax capabilities. • Input device installed as a circuit board inside the computer's system cabinet; a modem with fax capability that enables you to send signals directly from your computer to someone else's fax machine or computer fax modem. Why it's important:With this device, you don't have to print out the material from your printer and then turn around and run it through the scanner on a fax machine. The fax modem allows you to send information more quickly than if you had to feed it page by page into a machine. Fax modems are installed inside portable computers, including pocket PCs and PDAs. If you can also link up a cellular phone to a fax modem in your portable computer, you can send and receive wireless fax messages no matter where you are in the world. 38 slides

17. Fax modem Dedicated Fax Machine 38 slides

18. (2) Audio-input devices translate analog sounds (those with continuously variable waves) into digital 0s and 1s, either through audio boards or MIDI boards. • (3) Video-input cards translate analog film and videotape signals into digital form, using either frame-grabber video cards or full-motion video cards. • (4) Digital cameras use light-sensitive processor chips to capture photographic images in digital form. • (5) Voice-recognition systems convert speech into digital signals by comparing electrical patterns produced by voices with prerecorded patterns stored in a computer. • Why it's important: Voice-recognition technology is useful in situations where people are unable to use their hands to input data or need their hands free for other purposes. • (6) Sensors collect data directly from the environment and transmit it to a computer. • Why it's important:Although you are unlikely to see such input devices connected to a PC in an office, they exist all around us, often in nearly invisible form. Sensors can be used to detect all kinds of things: speed, movement, weight, pressure, temperature, humidity, wind, current, fog, gas, smoke, light, shapes, images, and so on. In aviation, for example, sensors are used to detect ice buildup on airplane wings and to alert pilots to sudden changes in wind direction. 38 slides

19. Caption: Earthquake sensor. 38 slides

20. Voice Recognition System 38 slides

21. (7) Radio-frequency identification (or RF-ID tagging)is based on an identifying tag bearing microchip that contains code numbers; these numbers are read by radio waves of a scanner linked to a database. • Also known as RF-ID tagging; a source data-entry technology based on an identifying tag bearing a microchip that contains specific code numbers. These code numbers are read by the radio waves of a scanner linked to a database. • Why it's important:Drivers with RF-ID tags can breeze through tollbooths without having to even roll down their windows; the toll is automatically charged to their accounts. Radio-readable ID tags are also used by the Postal Service to monitor the flow of mail, by stores for inventory control and warehousing, and in the railroad industry to keep track of rail cars. • (8) Human-biology input devices include biometric systems, which use biometrics the study of body characteristics, to identify people through biological characteristics, and line-of-site systems, in which people point their eyes at a screen. • Science of measuring individual body characteristics.Why it's important:Biometric security devices identify a person through a fingerprint, voice intonation, or other biological characteristic. For example, retinal-identification devices use a ray of light to identify the distinctive network of blood vessels at the back of the eyeball. 38 slides

22. Caption: Humane Society employee scanning a pet cat implanted with an RF-ID microchip to identify its owner. 38 slides

23. Output Hardwareconverts machine-readable information into people-readable form. Three types of output are softcopy, hardcopy, and other. • Softcopy refers to non-printed data, such as that shown on a display screen. Data on a display screen or in audio or voice form. This kind of output is not tangible; it cannot be touched. • A display screen (monitor, screen) shows programming instructions and data as they are being input and information after it is processed. Screen clarity is affected by dot pitch, or space between pixels (the small units on screen that can be turned on or off); by resolution, which involves the number of pixels per square inch; and by refresh rate, the number of times per second pixels are recharged. 38 slides

24. Why it's important:Dot pitch is one of the measures of display-screen crispness. For a .28dp monitor, for instance, the dots are 28/100ths of a millimeter apart. Generally, a dot pitch of .28dp will provide clear images. • Pixel: Short for "picture element"; the smallest unit on the screen that can be turned on and off or made different shades. Why it's important:Pixels are the building blocks that allow text and graphical images to be displayed on a screen. • Resolution: Clarity or sharpness of display-screen images; the more pixels there are per square inch, the finer the level of detail attained. Resolution is expressed in terms of the formula horizontal pixels x vertical pixels. Each pixel can be assigned a color or a particular shade of gray. Standard resolutions are 640 x 480, 800 x 600, 1024 x 768, 1280 x 1024, and 1600 x 1200 pixels. Why it's important: Users need to know what screen resolution is appropriate for their purposes. 38 slides

25. Refresh rate: number of times per second that screen pixels are recharged so that their glow remains bright. In general, displays are refreshed 45–100 times per second. • Why it's important: The higher the refresh rate, the more solid the image looks on the screen--that is, the less it flickers. 38 slides

26. Pixel Dot pitch Resolution 38 slides

27. Two types of monitors are CRT and flat-panel. A CRT (cathode-ray tube) is a vacuum tube. A flat-panel display consists of two plates of glass separated by a layer of a substance in which light is manipulated; one technology is liquid crystal display (LCD), in which molecules of liquid crystal create images by transmitting or blocking light. • CRT: (Cathode ray tube) Vacuum tube used as a display screen in a computer or video display terminal. Why it's important:This technology is found not only in the screens of desktop computers but also in television sets and flight-information monitors in airports. 38 slides

28. Flat-panel screens • active-matrix display, in which each pixel on screen is controlled by its own transistor and so the image is brighter and sharper, • or passive-matrix display, in which a transistor controls a row or column of pixels. Two common color and resolution standards for monitors are SVGA (the most common), which can produce 16 million possible colors, and XGA, which can produce 65,536 possible colors. 38 slides

29. 38 slides Caption: Softcopy vs. hardcopy versions of newspaper.

30. Hardcopy refers to printed output. • A printer prints characters or images on paper or another medium. Resolution of the image is measured by dpi (dots per inch), with more dots producing greater sharpness. • Two types of printers are impact printers and nonimpact printers. • Impact printers form images by striking a print hammer or wheel against an inked ribbon, leaving an image on paper; one type is the dot-matrix printers, which contains a print head of small pins. • Nonimpact Printers form characters or images without direct physical contact between printing mechanism and paper. • Three types of non-impact printers are laser, ink-jet, and thermal. • A laser printers creates images with dots like a photocopying machine; the printer uses a page description language, software that describes the images to the printer. (PDL) Software that describes the shape and position of characters and graphics to the printer. PostScript and PCL are common page description languages. Why it's important: Page description languages are essential to desktop publishing. • Non-impact printer that creates images with dots. As in a photocopying machine, images are produced on a drum, treated with a magnetically charged ink-like toner (powder), and then transferred from drum to paper. 38 slides

31. 38 slides Laser Printer

32. An ink-jet printers sprays electrically charged droplets of ink at high speed onto paper. • A thermal printer uses colored waxes and heat to burn dots onto special paper. • Printer that uses colored waxes and heat to produce images by burning dots onto special paper.The colored wax sheets are not required for black-and-white output. Thermal printers are expensive, and they require expensive paper. Why it's important:For people who want the highest-quality color printing available with a desktop printer, thermal printers are the answer. • A special kind of printer, the plotter, which may be ink-jet or electrostatic, produces high-quality graphics, such as maps, that are too large for regular printers. • Another category of printer is the multifunction printer, which combines printing, scanning, copying, and faxing in one device. 38 slides

33. Caption: How an ink-jet printer works. 38 slides

34. Plotter 38 slides

35. Other forms of output are sound, voice, and video. Sound-output devices produce digitized sound. • Voice-output devices convert digital data into speech-like sounds. • Video consists of photographic images, played at 15-29 frames per second; in one form of video output called videoconferencing people have online meetings using computers and communications devices that enable them to see and hear one another. 38 slides

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37. The Future of Input & Output • Increasingly, input will be performed in remote locations and will rely on source data automation. Future source data automation will include high-capacity bar codes, 3-D scanners, more sophisticated touch devices, smarter smart cards, more diverse sensors, better voice recognition, smaller electronic cameras, more sophisticated biometric devices, and even brainwave input devices. • Output, too, is being performed in remote locations. On the horizon are better, cheaper, and larger display screens; higher-fidelity audio using wave table synthesis and three-dimensional sound; and "real-time" video using digital wavelet theory. Thanks to 3-D technology, three-dimensional images can appear on computer displays and, through VRML software, users of the World Wide Web can experience 3-D "virtual worlds." 38 slides

38. Input & Output Technology & Quality of Life: Health & Ergonomics • The use of computers and communications technology can have important effects on our health. • Some of these are repetitive stress (strain) injuries (RSIs) such as carpal tunnel syndrome; computer vision syndrome, such as eyestrain and headaches; and back and neck pains. • Some people are concerned about electromagnetic fields (EMFs), waves of electrical and magnetic energy emitted from CRTs, cellphones, and the like. • Negative health effects have increased interest in the field of ergonomics, the study of the relationship of people to a work environment. 38 slides