Lec 5 output unit
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The document provides a comprehensive overview of computing fundamentals, focusing primarily on output units such as printers, monitors, and speakers, along with a detailed examination of different types of printers including dot matrix, laser, and inkjet. It also covers memory concepts, including primary and secondary memory types, their classifications, and operations such as reading and writing data. Additionally, the document discusses memory addresses, cache memory, and the mechanics of how monitors display images.
Lec 5 output unit
- 1. WELCOME
- 2. MIS – 104: Computing Fundamentals BBA Department of MIS University of Dhaka
- 3. 3 Books 1.Introduction to Computer Peter Norton 2. Computer Fundamentals Dr. M Lutfar Rahman 3. Computer Fundamentals Pradeep K. Sinha
- 4. 4 Previous class >>Organization of computer Input Unit Output Unit Memory unit Control Unit ALU
- 7. 7 Printer • Two types- Impact & non-impact • Impacts are Type writers like dot matrix, line printer, drum printer • Non-impact printer works by creating images like ink jet printer, laser printer, photo printer, Thermal printers.
- 8. 8 Dot matrix printer: Mechanism • Consists of print head which have a cluster (matrix) of short pins arranged in one or more columns • Receiving command from the CPU, the print head pushes the appropriate pins in and out of its cluster
- 9. 9 Dot matrix printer: Mechanism • Clusters in various combination can create various alphanumeric characters • When pin is out of cluster, produced pin strike the ribbon and press ink on the paper • The more pin in the cluster then higher the resolution
- 10. 11 Dot matrix printer: Advantages • Can make carbon copies • Lowest print cost per page • Ink ribbon does not easily dry out
- 11. 12 Dot matrix printer: Dis-advantages • Noise level is very high • Resolution is very low • Limited quality • Limited color performance • Low speed of printing
- 12. 13 Laser printer: mechanism • It uses laser light for printing mechanism • Just as the electron gun in a monitor can target at any pixel, the Laser in a laser printer can aim at any point on the drum, cresting a electric charge • The laser reflecting from the scanning mirror moving through the ‘beam alignment lens’ falls on imaging drum
- 13. 14 Laser printer: mechanism • Toner contains tiny particles of ink strikes to the drum in the places the laser has charged • Then with the pressure and heat, the toner is transferred off the drum onto the paper • The amount memory used, determines the speed of printing.
- 14. 16 Laser printer: Advantages • Very high speed • No irritating sound like dot matrix printer • Low noise level • Low maintaince requirements • High quality image • Excellent graphics quality • A variety type of size and qualities • Monochrome printing speed: 4-16 ppm • Resolution: 300, 600 dpi (high quality: 1200- 1800dpi)
- 15. 17 Laser printer: Dis-advantages • Printer is costly • Rough use can damage the lens and the mirror • Toner is costly and need to be changed after a thousand of page printed.
- 16. 18 Ink jet printers: requirements • Requires the ink nozzle containing CMYK • CMYK (cyan-blue, magenta-red, yellow, black) • Also requires specially coated papers
- 17. 19 Ink jet printers: Mechanism • Ink is exposed to UV radiation source where chemical reaction will take place • A shuttered mercury vapor lamp is on either side of print head & produces a great amount of heat to complete the curing process • UV do not evaporate rather cure
- 18. 20 Ink jet printers: Mechanism • Monomers due to UV ray forms polymer resulting high molecule which sets as a image on paper or plastic • No material is removed that means 100% of delivered volume is used to provide colorization
- 19. 22 Ink jet printers: Advantages • Do not need warm up time • Noise level is very low i.e. almost quite • Print finer, smoother with high resolution • Instant dry saves time • Printing Speed: 2-4 ppm • Resolution: 300 dpi, 600 dpi • Cartridge are less costly (than toner) • Most uses separate color cartridge and a BW cartridge which saves ink.
- 20. 23 Ink jet printers: Dis-advantages • Relatively slow printing • clogged jets when not used • Very narrow ink jet nozzle can coagulate with dry ink at the head
- 21. 24 Output device: Monitor • Categories based on the prime hardware used • Cathode ray tube (CRT) Ex- typical monitors with heavy weight • Flat-panel display Ex- LCD, LED etc
- 22. 25 Output device: Monitor • Categories based on the color display • Monochrome: One color on a black background • Grayscale: Shades of gray on a white or off-white background • Color: From 16 to 16 million unique colors
- 23. 26 Other kinds of monitor • Paper-white display • Electroluminescent (ELD) display • Plasma/gas plasma display
- 24. 27 Monitor : Phosphor dots • The only single unit dot which is responsible for the image display • There are ‘three types’ of phosphor dots they are red, green and blue i.e. RGB
- 25. 28 Monitor : Pixel • Pixel, short for picture element, is the smallest number of phosphor dots that the electron gun inside the monitor can focus on {01M pixel= 01 Million pixels} • Three phosphor dots combine to form a single unit pixel 01 pixel
- 26. 29 Resolution • The more you have pixels in your monitor you will be able to see the more clear and sharp image. • This sharpness is called resolution • For more resolution you must have more pixels per inch area on the monitor and minimum distance of dot pitch
- 27. 30 Refresh rate & Dot pitch • Refresh rate: It is the number of times per second that the electron guns scan every pixel on the screen • Dot pitch: The distance between the same color phosphor dots of the pixel
- 28. 31 Organization of (CRT) • Its main part is a ‘cathode ray tube’. • At its one end there is a source of high voltage. • There is a ‘magnetic coil/yolk’ ; which is used to control the flow of electron • At the back of the screen there are ‘phosphor dots’
- 29. 32 Mechanism • Electron gun shoots streams of electrons at a high voltage towards the screen • Magnetic coil controls the flow of electrons • Phosphor dots on the back of the screen glow when the electron beam hit them
- 30. 33 Mechanism : Scanning • Electron gun do not scan it randomly but in a designed fashion • The electron gun scans from left to right • Then from top to bottom • Refreshing every phosphor dot in a zigzag pattern
- 31. 34 Mechanism : Scanning left right top bottom Indicates pixel
- 32. 35 Why TV is not used as monitor? • Television display contains resolution which is just a half of computer monitor. So it cannot show output of computer operation. • Resolution indicates the sharpness of an image determined by the number of pixels on the screen. TV contains only the half number of pixels than monitor, so the resolution
- 33. 36 Advantages of CRT monitor • Refresh rate is high • Relatively low cost • Viewing angle is more i.e. can be seen from different angle
- 34. 37 Disadvantages of CRT monitor • Large In size • Not portable • Requires a lot of power to run it
- 35. 38 Advantages of FLAT PANEL(LCD) monitor
- 36. 39 Advantages of FLAT PANEL(LCD) monitor
- 37. 40 Advantages of FLAT PANEL(LCD) monitor • the pixels are addressed in rows and columns • The column and row wires attach to transistor switches, one for each pixel. • The one-way current passing characteristic of the transistor prevents the charge applied to the pixel from draining between refreshes to the display image
- 38. 41 Advantages of FLAT PANEL(LCD) monitor • Small in size, small space requires • Portable as weight is less than CRT monitor • High resolution • A little power consumption
- 39. 42 Advantages of FLAT PANEL(LCD) monitor • Small in size, small space requires • Portable as weight is less than CRT monitor • High resolution • A little power consumption
- 40. 43 Disadvantages of FLAT PANEL(LCD) monitor • Low refresh rate • Viewing angle is low • Images can be difficult to see in bright light
- 41. 44 Output unit: Speaker • Speaker is well known output device usually outputs sound • It is attached with the sound card of the computer • Sound can be controlled by controller • Electric signal is converted and it changes the air pressure outside which we call sound
- 42. 46 Output device: Touch screen
- 43. 47 Output unit: Plotter • A output unit like printer used to print large size posters • Requires specified paper and ink • It takes a few hours to print the poster
- 45. Memory Unit
- 46. 50 Memory Memory: – One or more set of chips that stores data or programmed instructions either temporarily or permanently. Classification of memory: 1. Primary memory 2. Secondary memory
- 47. 51 Location of different memories ALU MAIN MEMORY OR RESISTERS CONTROL UNITINPUT UNIT OUTPUT UNIT SECONDARY MEMORY
- 48. 52 Calculations of storage capacity 01 BYTE (B) 08 bit 01KB 1024 B 01 MB 1024.1024 B 01 GB 1024.1024.1024 B 01 TB 1024.1024.1024.1024 B
- 49. 53 Memory Terminologies • Memory Address: – Memory locations are identified by numbers 100 B X Y A 0000 0001 0002 FFFD FFFE FFFF
- 50. 54 Memory Terminologies • Memory Word: – When memory is read or written, a block of bit is read or written instead of a single bit. – The block is considered to be a unit of operation/processing – A set of bit with which read/write operation is done in a certain storage device is called memory word – Example: 08 bits or 01 Byte memory word clearly 01000000 (08 bits) represents 64 and its character is @; here, this digital 08 bits in combine known as a memory word 100 B X Y A 0000 0001 0002 FFFD FFFE FFFF
- 51. 55 Memory Terminologies • Destructive: – composed of capacitors, data disappears when read operation is done, needs re-write operation to retain data • Non-destructive: – reverse nature – Example: semiconductor, switch, flash memory, pen drive
- 52. 56 Memory Terminologies • Volatile: – Type of memory where data remains only when the power supply is on. – Ex-RAM • Non-volatile: – here content remains even the power is turned off – Example: hard disk, floppy disk, flash drive etc
- 53. 57 Memory Terminologies: Memory operation • Memory store/write: – The process of storing or writing data at the specific location of the memory – Data is stored as bits – Ex- CD writing operation
- 54. 58 Memory Terminologies: Memory operation • Memory read: – Also called ‘fetch operation’ – To read stored data or to process that stored data – A binary word is selected from a specific address of memory and this is transferred to another device – Example: To hear a song from CD or any drive
- 55. 59 Memory Terminologies: Memory access • Random access: – Any location of storage can be accessed at any moment – Does not matter whether the desired access location is too close or a far away – Consumes almost same amount of time – Found in primary and secondary memory
- 56. 60 Memory Terminologies: Memory access • Sequential: – accessing a bit of information in a serial order, one after another – Access time depends on the last order/information execution time – Example: Off line storage such as playing a song from magnetic tape
- 57. 61 Primary memory • Includes RAM & ROM • CPU access directly on this memory • Normally volatile in nature
- 58. 62 Primary memory: RAM • Central storage unit • Volatile • Temporary in nature • Holds operating systems, application programme, data in current use • Other name is (Read/Write) memory
- 59. 63 Different types of RAM • S RAM- Exhibits data remanance but still volatile as data dissolves when turn off • D RAM- Data disappears after a certain period automatically if it is not refreshed. This type of RAM needs periodically re- read or re-written. Ex- Z-RAM, TT-RAM, A-RAM
- 60. 64 Primary memory: ROM • Proportionally read operation is more than write operation • Contains user programmed instructions like Bootstrap loader • Non-volatile • permanent
- 61. 65 Different types of ROM ROM M ROM M ROM M ROM M ROM
- 62. 66 Secondary memory • Auxiliary unit • Storing capacity is huge • Normally non-volatile • Normally two types- 1. Magnetic 2. Optical
- 63. 67 Secondary memory: Magnetic • Variation of ‘Magnet polarity’ determines whether the bit will be 0 or 1 • Data write process is done by electromagnetic head • Ex- hard disk, floppy disk, magnetic tape
- 64. 68 Secondary memory: Optical • Variation of light reflection determines the nature of bits • Data is written with the help of LASER or UV rays • Ex-CD-R/RW, DVD-R/RW, BD-R
- 65. 69 Memory address: • It is a number or a set of digital number (bit/Bytes) in the memory • This address specially represented by binary numbers • Decimal, Octal, Hex-decimal numbers are also used for addressing
- 66. 70 Virtual memory: • When secondary memory is used as primary memory then this is called virtual • Provide assistance to the RAM, by creating space for the great amount of data • When RAM finishes it’s access, virtual memory vanishes • Virtual memory can be selected by user
- 67. 71 Cache memory: • Small memory chip is attached between CPU & main memory • Give the assistance to the resisters • Speed up the data process • Three types of cache memory is found e.g. L1(CPU resident), L2 & L3 (mother board)
- 68. 72 Resisters • They are not the part of main memory but store data and pass as directed by CPU • The size of the resisters which is sometimes called the word size,indicates the amount of data with which CPU can work/access. • Ex- 32 bits processor means, 04 bytes data processing capability
- 69. Question...???