5 1 Chapter Perangkat Keras Input masukan Output
- Slides: 34
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Chapter Perangkat Keras: Input (masukan) & Output (Keluaran) 5 5. 1 Masukan & Keluaran 5. 2 Perangkat keras masukan 5. 3 Perangkat keras keluaran 5. 4 I/O Quality of Life: Kesehatan dan Ergonomika 5. 5 Masa depan I/O Mc. Graw-Hill/Irwin © 2007 The Mc. Graw-Hill Companies, Inc. All rights reserved.
Masukan dan keluaran u. Perangkat keras Masukan u Perangkat yang menerjemahkan data ke dalam bentuk yang komputer dapat mengolahnya u Menerjemahkan kata-kata, bilangan, suara, dan gambar ke dalam bentuk biner u. Perangkat keras keluaran u Perangkat yang menerjemahkan informasi yang terolah oleh komputer ke dalam bentuk yang manusia dapat memahaminya. u Menerjemahkan data bentuk binerbinary ke dalam kata, bilangan, suara, dan gambar 5 -3
Input Hardware u Keyboards: convert letters, numbers, and characters into electrical signals u English keyboards differ from foreign language keyboards u Follow this link to see what a Russian Cyrillic keyboard layout looks like u http: //www. geocities. com/fontboard/cyrillic. html u Even languages that are close to ours like German have different keyboard layouts, such as can be seen on Microsoft’s web site u http: //www. microsoft. com/globaldev/keyboards/kbdgr. htm u Even touch typists must watch their fingers when they travel to Internet Cafes in foreign countries! 5 -4
Input Hardware u How keyboards work: u You press a key u This interrupts the current flowing through the circuits u Processor determines where the break occurs u It compares the location of the break with the (x, y) character map for the language on the keyboard’s ROM chip u A character is stored in 16 -byte keyboard memory buffer u Then sent to PC as a data stream via wire or wireless connection u OS interprets its own operating-system-specific commands and sends the others to the application for interpretation 5 -5
Input Hardware u. Keyboard types u 104 – 108 keys desktop standard u 85 keys for laptops u Wired u Connect u Wireless to CPU via a serial or USB port use either u IR (infrared) technology u Radio Frequency (RF) technology u Require line of sight to connect u Virtual keyboard used with PDAs and smartphones 5 -6
Input Hardware Terminal Types u Dumb Terminals u a. k. a. Video Display Terminal (VDT) u Has display screen and keyboard u Can do input and output only – no data processing u Intelligent Terminals u Has screen, keyboard, and memory u Can perform some local functions u Internet Terminals u Powers directly up into a browser u Web terminal displays web pages on a TV set u Network computer is a stripped-down PC to connect people to networks u Online game player connects to internet for online gaming u PC/TV merges a full-blown PC with a TV u PDA is a handheld computer with a tiny keyboard 5 -7
Input Hardware u. PDA Keyboards u Problem: Make them too small and they are unusable u Problem: Make them too big and the PDA is too big u Solutions: u Some PDAs use a stylus u Some PDAs use a foldable keyboard u Some PDAs use a 20 -key mini-keyboard 5 -8
Input Hardware Pointing Devices u Control the position of the cursor or pointer in the screen and allow the user to select options displayed on the screen u Mouse is the principal pointing tool u Rolls around on a mouse pad or desktop and directs a pointer on the computer’s display screen u Ball inside the mouse touches the desktop and rolls around u Two internal rollers touch the ball u One roller picks up motion in x (up), the other in y (down) u The rollers turn a shaft that spins a disk that breaks an LED signal into light pulses that are seen by an infrared sensor u Processor chip in mouse reads the pulses and turns it into binary Discussion Question: What is the difference between “cursor” and “curser”? 5 -9
Input Hardware Pointing Devices u. Trackball u. A movable ball mounted on top of a stationary device u Good for locations where a mouse couldn’t move enough u Requires more frequent cleaning to remove finger oils u. Touchpad u To use: slide your finger over this small flat surface u Click by tapping you finger on the surface u May require more practice to use than a mouse u. Pointing Stick u Looks like a pencil eraser in the lower center of a laptop keyboard 5 -10
Input Hardware Pointing Devices u. Touch Screens u. A video display screen sensitized to receive input from a finger u Cruder than a mouse, because fingers are big u Problems: touch screens that show a display that is not precisely aligned with the input u. Pen input u Use a pen-like stylus for input rather than typing on a keyboard u Use handwriting recognition to translate cursive writing into data 5 -11
Input Hardware u. Light Pen u. A light-sensitive pen-like device that uses a wired connection to a computer terminal u Bring the pen to the desired point on the display screen and press a button to identify the screen location u Used in situations that require gloves u Less crude than a touch screen u. Digitizer u Uses an electronic pen or puck to convert drawings and photos to digital data u Digitizing tablets are used in architecture 5 -12
Input Hardware Scanning & Reading Devices u. Source Data Entry devices create machine-readable data and feed it directly into the computer u Scanners u Use light-sensing equipment to translate images of text, drawings, and photos into digital form u Image scanners are used in electronic imaging u Resolution refers to the image sharpness, measured in dots per inch (dpi) u Flatbed scanners work like photocopiers – the image is placed on the glass surface, then scanned u Other types are sheet-fed, hand-held, drum, and pen scanners 5 -13
Input Hardware Bar-Code Readers u Photoelectric (optical) scanners that translate bar code symbols into digital code u The digital code is then sent to a computer u The computer looks up the item and displays its name and pricing info u Bar code types u 1 D holds up to 16 ASCII characters u 2 D can hold 1, 000 to 2, 000 ASCII characters u 3 D is “bumpy” code that differentiates by symbol height u Can be used on metal, hard rubber, other tough surfaces 5 -14
Input Hardware Mark Recognition Readers u. Bar code readers u MICR – Magnetic-ink character recognition u Uses special magnetized inks u Must be read by a special scanner that reads this ink u OMR – Optical mark recognition u Uses a special scanner that reads bubble marks u Used in standardized tests like the ACT and SAT u OCR – Optical character recognition u Converts scanned text from images (pictures of the text) to an editable text format u You use this to read in non-computer documents where you don’t have the source files 5 -15
Input Hardware Fax Machines u. Facsimile Transmission Machines – scan an image and send it as electronic signals over telephone lines to a receiving fax, which prints out the image on paper u Dedicated fax machine u Is a stand-alone unit that only sends and receives faxed documents u Fax modem u Is a circuit board installed in the PC u Is a modem that can send and receive faxes Can send documents directly from your word processor to a fax machine u Saves you printing out the document, then faxing it u 5 -16
Input Hardware Audio Input Devices u. Records analog sound and translates it into digital files for storage and processing u. Two ways to digitize audio u Sound Board u An add-on board in a PC that converts analog sound to digital sound, stores it, and plays it back to speakers or amp u MIDI Board u Stands for Musical Instrument Digital Exchange u Uses a standard for the interchange between musical instruments, synthesizers, and PCs 5 -17
Input Hardware Webcams and Video-input Cards u. Webcams u Video cameras attached to a computer to record live moving images then post them to a website in real time u Require special software, usually included with the camera u. Frame-grabber video card u Can capture and digitize 1 frame at a time u. Full-motion video card u Can convert analog to digital signals at rates up to 30 frames per second u Looks like a motion picture Discussion Question: Why might it be unwise to install a webcam on your PC? 5 -18
Input Hardware Digital Cameras u. Use a light-sensitive processor chip to capture photographic images in digital form and store them on a small diskette in the camera or on flash memory cards u Most can be connected to a PC by USB or Fire. Wire u Can allow you to take more pictures and decide which ones to print and save u But pictures are subject to loss by diskette or flash memory failure or computer virus if you store them on the PC 5 -19
Input Hardware Camera Phones u. Digital cameras are now on cellphones u Convenience of being able to take photos, then instantly email or message them to someone else u Can provide instant record of traffic accidents, etc Discussion Question: Why do you suppose cellphones are now banned on secure U. S. military bases? Where else besides military bases might they pose a security problem? 5 -20
Input Hardware Speech-Recognition Systems u. Uses a microphone or telephone as an input device. Converts a person’s speech into digital signals by comparing against 200, 000 or so stored patterns. u Used in places where people need their hands free – warehouses, car radios, stock exchange trades u Helpful for people with visual or physical disabilities that prevent them from using other input devices u Still not easy enough to use to substitute for the mouse/keyboard for fast document processing u Scan. Soft’s Open Speech Dialog u Apple Speech Recognition u Scan. Soft’s Navigon Mobile. Navigator 5 5 -21
Input Hardware RFID Tags u. Radio-frequency ID tags are based on an identifying tag with a microchip containing specific code numbers u Scanners use radio waves to read them and match the codes to a database u Enables items to be tracked without physical contact u Drivers put RFID tags in cars to automatically pay tolls u FDA is tagging certain drugs with RFID to avoid counterfeits u Carmakers are using it for car electronic keyless entry u RFID tags are implanted under skin of pets to aid in recovery and identification when they get lost 5 -22
Input Hardware Biometrics u. The science of measuring individual body characteristics, then using them to identify a person through a fingerprint, hand, eye, or facial characteristic u Becoming a big business as more companies become concerned about security u Makes identity theft much more difficult when records are identified by biometrics as well as passwords u For more information see u http: //www. xtec. com/home. html u http: //www. identix. com/ u http: //www. precisebiometrics. com/ 5 -23
Output Hardware u. Softcopy u Data that is shown on a display screen or is in audio or voice form; exists electronically u Output that is ephemeral in nature u. Hardcopy u Printed and film output u Output that is more permanent in nature 5 -24
Output Hardware Display Screens u Making a good choice when choosing a display u Dot pitch (dp) is the amount of space between adjacent pixels (picture elements) on screen u The closer the pixels, the crisper the image u Get. 25 dp or better u Resolution refers to the image sharpness u The more pixels the better the resolution u Expressed in dots per inch (dpi) u Color depth or bit depth is the number of bits stored in a dot u The higher the number the more true the colors u 24 -bit color depth is better than 8 -bit color depth u Refresh rate is the number of times per second the pixels are recharged – a higher rate gives less flicker 5 -25
Output Hardware Monitors u. Cathode Ray Tube (CRT) is a vacuum tube used in a computer or terminal display screen u Watch the PC ads to make sure your monitor is included u. Flat panel displays are made of 2 plates of glass separated by a layer of liquid crystals that line up to transmit or block light u Preferable to CRTs because they take up less room on the desktop u Latency problems make them less desirable for online games players 5 -26
Output Hardware Monitors u Video Standard u Principal resolution (pixels) u SVGA u 800 x 600 u 1024 x 768 u 1280 x 1024 u 1600 x 1200 u 2048 x 1536 u XGA u SXGA u UXGA u QXGA 5 -27
Output Hardware Printers u Impact Printers u Form characters or images by striking a print hammer or wheel against an ink ribbon u Dot matrix printers u Laser Printers u Use drums and toner like in photocopiers u Inkjet Printers u Spray ink from 4 nozzles at high speed u Page Description Language (PDL) u Post. Script and PCL are PDL types u Produce crisp, professional pages u Quiet, inexpensive color printers u Often less precise than laser printers u Thermal Printers u Low to medium resolution printers that use thermal paper that darkens in time 5 -28
Output Hardware Plotters u. A specialized output device designed to produce large high-quality graphics in a variety of colors u The earliest output device that could produce graphics u Pen plotters use one or more colored pens u Electrostatic plotters lie partially flat on a table and use toner like photocopiers u Large-format plotters are large-scale inkjet printers used by graphic artists 5 -29
Output Hardware Mixed Output u. Sound output u You need a sound card and sound software u Good equipment can produce very high-quality 3 -D sound u. Voice Output u TTS systems (text to speech) are becoming popular u Requires a sound card and speakers with TTS software u. Video Output u Requires a powerful processor and a video card u Video files are large, so a lot of storage is needed too. 5 -30
I/O Quality of Life: Health & Ergonomics u. PCs impact health u Overuse injuries and repetitive stress injuries u Result when muscle groups are forced through fast, repetitive motions u May effect data-entry operators who average 15, 000 keystrokes an hour u May effect PC users whose monitor, keyboard, and workstation are not arranged for comfort u Carpal tunnel syndrome is caused by pressure on the median nerve in the wrist, caused by short repetitive movement u Computer vision syndrome is eyestrain, headaches, and double vision caused by improper use of computer display screens 5 -31
I/O Quality of Life: Health & Ergonomics u. Ergonomics is the methodology of designing a workplace to make working conditions and equipment safer and more efficient u Keyboards must be placed at the correct height depending on each worker’s size u Monitor refresh rates must be fast enough to avoid eyestrain u Monitor heights must be correct for comfortable viewing u Sound-muffling should be used for loud printers to reduce workplace noise u Wrist rests may help avoid carpal tunnel syndrome 5 -32
Future of Input and Output u. This is a fruitful area for research, including u Intelligent sensors u More data input from remote locations u More source data automation u Input help for the disabled u More sophisticated touch devices u Better speech recognition u Improved digital cameras u Gesture recognition 5 -33
Future of Input and Output u. This is a fruitful area for research, including u Pattern-recognition and biometric devices u Brainwave devices u Better and cheaper display screens u Improved video on PCs u 3 -Dimensional output u Miniaturization for improved data transfer speeds to I/O devices 5 -34
- Perangkat keras masukan
- Struktur dan unit fungsional dasar komputer
- Contoh perangkat keras dan lunak
- Apa itu peripheral input
- Perangkat keras internet
- Dibawah ini termasuk piranti masukan adalah kecuali
- Pengenalan perangkat keras komputer
- Peta konsep perangkat komputer
- Perangkat penyimpan data
- Mengidentifikasi berbagai komponen perangkat keras komputer
- Jenis perangkat keras server
- Pengenalan perangkat keras komputer
- Mengenal perangkat keras komputer
- Perangkat keras untuk mengakses internet
- Fungsi wireline
- Perangkat keras komunikasi data
- Definisi perangkat keras
- Buatlah peta konsep rangka manusia
- Perangkat keras storage
- Pengenalan perangkat keras komputer
- Ms excel merupakan aplikasi pengolah
- Perangkat keras hardware adalah
- Komponen komponen perangkat keras
- Perangkat keras komputer
- Contoh perangkat keras
- Chapter 6 input and output
- Laptop input devices
- Chapter 15 input output java
- Chapter 2 input processing and output
- Perangkat output adalah
- Piranti input
- Piranti masukan dan keluaran
- Piranti masukan dan keluaran
- Apa yang dimaksud peranti masukan tekstual
- Masukan mentah