Hardware Devices Module 1.2 PDF

HARDWARE Module DEVICES 1.2 1 HARDWARE Module DEVICES 1.2 2  CONTENT The information processing cycle Input devices Output devices Storage devices Communication devices Test and improve your knowledge...

HARDWARE Module DEVICES 1.2 1 HARDWARE Module DEVICES 1.2 2  CONTENT The information processing cycle Input devices Output devices Storage devices Communication devices Test and improve your knowledge 3  THE INFORMATION PROCESSING CYCLE 4  THE INFORMATION PROCESSING CYCLE Input Processing Output Keyboard CPU Screen Mouse RAM Printer Touch pad Data Touch projector screen Touch screen Storage Speakers Communication Hard drive ADSL Flash modem/router drive Computers take data Cellular 3G Optical modem and process it into media WiFi information. Switch 5 THE INFORMATION PROCESSING CYCLE Identifying data needed Input deciding how to capture data planning and creating data capture forms and instructions directly sent to storage Output directly communicated to other computers used as input 6  COMBINING INPUT SOURCES AND OUTPUT DESTINATIONS Most ICT systems use multiple input sources and output destinations to enhance productivity. Sensors to detect movement Smartphone or tablet and may have Onscreen controls POS (Point Of Sale) system may use Specialised till keyboard + barcode scanner + card reader + fingerprint scanner Musicians may connect MIDI (Musical Instrument Digital Interface) piano keyboard + computer using USB + keyboard and mouse 7  PROCESSING Processing  only takes place if software and data is loaded into RAM  uses a step-by-step solution (called an algorithm)  uses data that has been input, creates information that can be output. Processing typically involves tasks such as searching sorting mathematical calculations. 8  STORAGE Choose appropriate storage media. Security. Good backup policies. 9 INPUT DEVICES 10  INPUT DEVICES  Allows the ICT device to receive data and instructions.  First step in any information processing system. 11  KEYBOARD Uses Advantages Limitations Typing in text Fastest way to enter Not designed to be Giving commands text used with a GUI Easy to learn and use interface Takes up space Can be difficult to use for some people Skills required 12  KEYBOARD  Factors – buying decisions  Ergonomic considerations  Wireless vs. cabled  Problem solving  The keys are sticky: clean it with a damp cloth.  Wireless keyboard not responding : batteries.  Wired keyboard not responding: disconnect and re-connect. 13  MOUSE Uses Advantages Limitations Interact with GUI Easy-to-learn Best used with a fixed Click, double-click, Effective way to workplace and suitable right-click, scroll, drag interact with GUI surface area Can be used whilst Better devices for pressing a key on the drawing or other keyboard graphical actions available 14  MOUSE  Factors – buying decisions  Ergonomic considerations  Wireless vs. cabled  Problem solving  Sticky mouse: remove dust or lint underneath and use a smooth, non-reflective surface.  Wireless mouse not responding: batteries.  Wired mouse not responding: disconnect and re-connect. 15  TOUCH SCREEN Uses Advantages Limitations Replacement for Functions as both a On-screen keyboard mouse mouse and keyboard harder to use than a Addition to mouse Natural input, such as physical keyboard and keyboard gestures Some touch screens need extra pressure to work Best interface for Natural interactions, such systems with as swiping, pinching, The quality of the ‘touch experience’ depends on limited options expanding the OS being used Easy to use, intuitive On-screen keyboards Increases space available reduce screen display for the display area Increases usability of the Not easy to use for device certain tasks 16  TOUCH PAD Uses Advantages Limitations Replaces the mouse The user does not have Not as accurate or in devices such as to carry an extra precise as a mouse laptops device such as a Difficult to use with drag mouse and drop operations Same actions as Difficult to use because mouse, without extra of limited size of the surface area or desk touch pad 17  SCANNER Uses Advantages Limitations To capture images Converts documents Quality of image depends from paper into digital format for on quality of the original To capture images of storage image text and convert with Converts image to Can be affected by dirt or OCR to editable text editable text with OCR fingerprints on the glass To read barcodes Converts old film or dust on the sensor photos into digital Works best with single format pages Benefits environment Books can be difficult to as less paper and ink scan are used Can take a lot of time 18  SCANNER-SPECIFIC ADVANTAGES Office Automation POS and database Other uses Large documents – Library and Point of Number plates of cars scanned and combined Sale (POS) systems as can be scanned and into a single digital file they provide quick and recorded quickly on Digital copies saves accurate input roads using e-toll office space Access control systems Scanned copies can be ranging from swipe e-mailed cards to radio tags Older documents can be archived 19  SCANNER  Problem solving  Errors in image size or quality: check the settings on the scanning software.  Non-responsive scanner: check if  it is switched on  it is plugged in  it is properly connected to the USB port  the lock switch is switched off. 20  DIGITAL CAMERA Uses Advantages Limitations To capture images Photos in digital format Photos are easy to To capture videos Easy to use lose along with the Alternative to Not expensive to take device scanners as barcode many photographs The quality of photos or QR code readers if You can instantly view depends on the the camera is them quality of camera integrated with a Doubles up as good video smartphone camera Built into devices Photos are easy to share 21  DIGITAL CAMERA  Factors – buying decisions Resolution  The number of horizontal and vertical pixels in the image  Minimum of 300 dpi to get good images for printing  72 dpi suitable for on-screen/web display  Image quality depends on:  Colour depth – the higher, the better (32 bits is currently the maximum).  Sensor size – the bigger, the better.  ISO rating – the camera’s sensitivity to light. 22  WEBCAM Uses Advantages Limitations Internet video Cheap Very low resolution -- communication Small doesn’t create good ‘Live feeds’ of events Often built into images Remote control portable computers Needs to be connected security cameras Allows for video calls to an ICT device to where you can see the work person you are talking to 23  WEBCAM  Problem solving  If the webcam is unresponsive, check that it is  plugged in properly  switched on  selected as the current camera to be used by the software.  The webcam software can often be used to test if the webcam is functioning properly and to troubleshoot problems. 24  MICROPHONE Uses Advantages Limitations Recording sound Record dictation Built-in microphones Communicating Give voice commands don’t generally provide Adds the input of sound to high quality sound a computer One needs to have the Uses software involving ICT device present to sound editing, analysis or record sounds manipulation Difficult to use in noisy environments 25  WRITTEN MODULE ACTIVIT Y  Page 31  Complete questions 1 – 23 26 OUTPUT DEVICES 27  OUTPUT DEVICES  Output is how an ICT device shows the results of the processing that has taken place. 28  MONITOR OR DISPLAY Uses Advantages Limitations Interactive feedback Immediate feedback Quality of the display is Extra visual alerts Interaction between the related to the size of for hearing impaired user & computer the monitor people Displayed content can be Size of the monitor easily changed limits portability Text can be enlarged for Output is difficult to the visually impaired / share (unless with a high contrast can be used projector) Display can be changed Image quality can be to suit the preferences of affected by ambient the user light 29  MONITOR OR DISPLAY  Factors – buying decisions  Resolution number of horizontal pixels multiplied by the number of vertical pixels (e.g. 1024 x 768).  Image quality  Colour depth – the higher, the better (32 bits is currently the maximum).  Pixel density – a higher pixel density makes the display crisper, clearer and easier to read.  Refresh rate – the higher, the better.  Contrast ratio – the relationship between the darkest black and the brightest white. Low contrast ratios produce soft, ‘muddy’ images. 30  MONITOR OR DISPLAY  Problem solving Problem Solution The colours are faded, too strong or Adjust the settings. muddy, or the image is too bright or too dim. The image is ‘blocky’ or stretched. The resolution settings are probably wrong. The image is tinted purple, blue, yellow or The connection is faulty and a pin in the green. VGA connector is probably bent. There is no display. The power is off/not switched on; the connection is not in properly, the computer is not /cable is not connected. 31  SPEAKERS OR HEADPHONES Uses Advantages Limitations Play sound Headphones – listen to Sound quality Provide audible sounds without disturbing depends on the feedback to the other people around you quality of the user Speakers – a group of peripheral Provide extra people can hear sound To play loud enough notifications or Listen to voice messages or for a group you will alerts to people interact on Skype using need additional with visual speakers and headphones audio equipment, disabilities Headphones make it such as an external possible to use mobile amplifier devices on the go 32  SPEAKERS OR HEADPHONES  Problem solving  If speakers or headphones are unresponsive  they might be plugged into the wrong jack (e.g. the microphone jack)  the computer’s sound settings may be low or on mute  the computer might be set to use the wrong sound output device  speakers that need power might be switched off or not be plugged in 33  PRINTERS Uses Advantages Limitations Laser printer Laser printer Laser printer Print black and white or Speed Expensive to buy colour documents High quality text Not the best for printing good Inkjet printer Low running costs quality colour photos Inkjet printer Toner is not absorbed by the Print black and white or paper colour documents Cheaper to buy Dot-matrix printer Best quality photographic Inkjet printer printers Higher running costs Most often used as POS Dot-matrix printer Slower printing speeds (Point Of Sale) printer for General print quality is not as receipts, invoices, etc. Cheap good as that of laser printers Low running costs Can create ‘carbon Dot-matrix printer copies’ Low print quality 34  PRINTERS  Problem solving  The printer is unresponsive:  Not plugged in/ power is off  Not properly connected.  The wrong printer is selected in the print dialogue box.  Content is incorrect or does not make sense:  Wrong printer driver is installed  Poor picture quality  Ink appears faded or irregular - low on ink or toner  May be the wrong type of paper  Network printer is not working: Network settings for printer or computer are wrong 35  PRINTERS  Factors – buying decisions  Speed – pages per minute.  Colour – separate cartridges for colours are better  Resolution – higher resolution gives better image  Cost per page  Paper – type of paper for high quality printouts.  System compatibility – can it be used with a specific OS?  Wireless capability - built-in wireless functionality, Bluetooth, Ethernet port.  Mobility – not generally mobile. 36  LCD PROJECTOR Uses Advantages Limitations To project a large image Allows the display to be Quality and clarity of of the display onto a viewed by a large group of not as good as high surface to share it with a people quality display large audience monitors The lower contrast ratios result in muddier images Normally limited to a 4:3 aspect ratio 37  WRITTEN MODULE ACTIVIT Y  Page 32  Complete questions 24 – 30 38 STORAGE DEVICES 39  HARD DRIVE Uses Advantages Limitations To store data and Larger capacity than Easy to damage software permanently RAM Comparatively slow – Make backup copies of Cheaper per GB than operates on a data and software RAM magnetic and Act as ‘virtual memory’ Store data and mechanical basis programs 40  HARD DRIVE Problem solving  Slow and unresponsive system  Disk may be fragmented.  Use a disk defragmentation utility to  re-arrange the files  to place scattered parts into whole chunks  for faster access to the files. 41  HARD DRIVE  Problem solving  If the storage space is full  delete or remove some files  get extra storage  add another hard drive  use external storage devices  use cloud storage.  If files are corrupted  use the Scandisk utility to fix the disk May be caused by improper shut down, crashing programs or power failures. 42  EXTERNAL HARD DRIVE Uses Advantages Limitations Store and carry media, Large capacity Not physically as small data and software Portability as a flash drive around with you As vulnerable as hard Ease of use Store backups safely, drives and can be High speed away from the damaged easily computer Reliability because they are Add extra storage to mechanical and the computer, without magnetic physically opening the computer 43  FLASH DRIVE Uses Advantages Limitations To carry data and Portability Easy to lose software around Fast data access More expensive per with you Cheap GB than hard drives To make backups Larger capacities than Lower capacities To distribute data optical media than newer hard and software Industry-standard use drives Reliability A limited life span in terms of how many Ease of use (in terms of times data can be adding and deleting files) saved on them No need for a power source 44  OPTICAL MEDIA (CDS/DVDS) Uses Advantages Limitations To distribute Cheap Slow software Portable Easily damaged To distribute content Industry-standard Relatively small capacity such as movies and use (700 MB for a CD, 4.7 to 9.4 music GB for a DVD) Back up Not as easy or intuitive to write to as flash disks Some machines like Netbooks do not have optical drives built-in 45  OPTICAL MEDIA (CDS/DVDS)  Problem solving  Often fail or experience problems because they get dir ty.  Clean a disc by wiping it with a soft damp cloth.  Easily damaged and scratched.  Difficult to repair. You usually have to replace it.  Writeable and re-writeable discs are easily damaged by heat or cold.  Nothing can be done to fix this damage. 46  SSD (SOLID STATE DRIVE) Much faster than normal hard drives. No moving parts – can’t be damaged by being dropped or moved whilst in use. Much more energy-efficient, durable and run quieter than traditional (mechanical) hard drives. Much more expensive and have smaller capacities than traditional hard drives. Sizes range from 8 GB to 750 GB (in early 2013), but sizes are increasing rapidly. 47 COMMUNICATION DEVICES 48  3G MODEM Uses Advantages Limitations Can access the Easy to install and use Can get lost or stolen Internet wherever there (use USB port) fairly easily is cellphone reception Small enough to take Not always as reliable with you for Internet as a fixed line access on any connection computer 3G Internet connection The 3G/4G network is depends on the fast coverage and strength of the 3G signal 49  ADSL MODEM/ROUTER Uses Advantages Limitations A digital link to the You can make and receive Needs specialised telephone phone calls and be equipment installed at company’s connected to the Internet the telephone network at the same time exchange, better Includes the Cheaper connections to the suited for urban areas functionality of a Internet than 3G Speed drops the small switch, More stable as it does not further the further you wireless (WiFi) depend on things like are away from the cellphone reception connectivity and a telephone exchange router Allows wireless connection Designed for fast to router to share an downloads and slower Internet connection uploads 50  WRITTEN MODULE ACTIVIT Y  Page 32, 33  Complete questions 31 – 43 51 TEST AND IMPROVE YOUR KNOWLEDGE 52  WE CONSIDERED THE FOLLOWING DEVICES Keyboard Mouse Touch screen Touch pad Input devices Scanner Digital camera Webcam Microphone Monitor or display Speakers or headphones Output devices Printer LCD projector Hard drive External drive Storage devices Optical media (CDs/DVDs) SSD Communication 3G Modem devices ADSL modem/router 53  WRITTEN MODULE ACTIVIT Y  Page 33, 34  Complete questions 44 – 58 54