Intro to computer fundamentals

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Intro to computer fundamentals

  1. 1. Introduction to Computers IT Preparatory Course Diploma in Nursing Unity College International
  2. 2. Are you a beginner <ul><li>With computers? </li></ul><ul><li>This course will helps you learn about computers in an easy, friendly way </li></ul>
  3. 3. Compare a computer <ul><li>To a workshop such as </li></ul><ul><ul><li>Woodshop </li></ul></ul><ul><ul><li>Kitchen </li></ul></ul>
  4. 4. Typical workshop features <ul><li>Materials </li></ul><ul><li>Tools </li></ul><ul><li>Working Area </li></ul><ul><li>Storage </li></ul><ul><li>Measurements (may be English or metric) </li></ul>
  5. 5. Woodshop <ul><li>Materials: Wood </li></ul><ul><li>Tools: Hammer, saw, drill… </li></ul><ul><li>Work area: Worktable </li></ul><ul><li>Storage: Cabinet </li></ul><ul><li>Measurements Yards, feet, inches, meters, centimeters, millimeters </li></ul>
  6. 6. Kitchen <ul><li>Materials: Food </li></ul><ul><li>Tools: Stove, mixer, spoon… </li></ul><ul><li>Work Area: Counter, cutting board, bowl… </li></ul><ul><li>Storage: Refrigerator, cabinet… </li></ul><ul><li>Measurements: Cups, tablespoons, teaspoons, ounces pints, grams, liters </li></ul>
  7. 7. Computers <ul><li>How does this apply to computers? </li></ul><ul><li>You will find materials, tools, work area, storage, and measurements </li></ul>
  8. 8. Computer Materials <ul><li>Information </li></ul><ul><ul><li>Words </li></ul></ul><ul><ul><li>Numbers </li></ul></ul><ul><ul><li>Pictures </li></ul></ul>
  9. 9. Computer Tools <ul><li>Two kinds: </li></ul><ul><ul><li>Hardware </li></ul></ul><ul><ul><ul><li>Physical parts to computer </li></ul></ul></ul><ul><ul><li>Software </li></ul></ul><ul><ul><ul><li>Instructions </li></ul></ul></ul><ul><ul><ul><li>This slide show for example </li></ul></ul></ul>
  10. 10. Computer Working Area <ul><li>The work area of a computer is called a window. </li></ul><ul><li>The next slide shows a typical window. </li></ul><ul><li>You will use some windows in the last part of this class and in future classes. </li></ul>
  11. 11. Typical Window
  12. 12. Computer Storage <ul><li>Two main types: </li></ul><ul><ul><li>Memory </li></ul></ul><ul><ul><li>Data Storage </li></ul></ul>
  13. 13. Memory <ul><ul><li>Often called RAM (Random Access Memory) </li></ul></ul><ul><ul><li>Information while you work on it </li></ul></ul><ul><ul><ul><li>(like food while you eat it) </li></ul></ul></ul><ul><ul><li>Usually temporary (easily lost) </li></ul></ul>
  14. 14. Data Storage <ul><ul><li>Information stored away for use later on </li></ul></ul><ul><ul><ul><li>(like food in the refrigerator) </li></ul></ul></ul><ul><ul><li>Usually long-term (safer) </li></ul></ul><ul><ul><li>May be stored on disks, CDs. DVDs, or flash drives </li></ul></ul>
  15. 15. Measuring Information <ul><li>Bytes </li></ul><ul><ul><li>One character takes up about one Byte . </li></ul></ul><ul><ul><li>An email takes up a few (thousand bytes) Kilobytes (thousands of bytes) </li></ul></ul><ul><ul><li>A picture may take up Megabytes (millions of bytes) </li></ul></ul><ul><ul><li>All the information on a computer may run into Gigabytes (billions of bytes) </li></ul></ul>
  16. 16. Storage Examples Email, about a thousand characters Picture of granddaughter, about half a megabyte
  17. 17. Hardware <ul><li>Central Processing Unit (cpu) </li></ul><ul><ul><li>Brains of a computer </li></ul></ul>
  18. 18. Disks <ul><li>Floppy Disk </li></ul><ul><ul><li>Main disk used for library users </li></ul></ul><ul><ul><li>Holds 1.44 Megabytes </li></ul></ul><ul><ul><ul><li>1,440,000 Bytes </li></ul></ul></ul><ul><ul><li>Feels hard </li></ul></ul><ul><ul><ul><li>Floppy part inside cover </li></ul></ul></ul><ul><ul><li>Almost obsolete </li></ul></ul>
  19. 19. Hard Disk <ul><li>Main disk for most computers </li></ul><ul><li>Holds Windows, software, and most data </li></ul><ul><li>Usually don’t see it because it’s inside computer. </li></ul>
  20. 20. CD-ROM <ul><li>Uses optical (laser) technology instead of magnetic </li></ul><ul><li>Holds large amount of data </li></ul><ul><li>Same technology as a music disk. </li></ul><ul><li>Not available on library computers </li></ul>
  21. 21. Disks <ul><li>Disk geometry may vary </li></ul><ul><ul><li>Different disks may have different number of sectors per track </li></ul></ul><ul><ul><li>Hide these details using a virtual geometry presented to the OS </li></ul></ul><ul><ul><li>Virtual geometry defined by x cylinders, y heads, and z sectors per track </li></ul></ul><ul><ul><li>Disk controller maps virtual to real geometry </li></ul></ul><ul><ul><li>Alternative: logical block addressing </li></ul></ul><ul><ul><ul><li>disk sectors numbered consecutively starting at 0 </li></ul></ul></ul><ul><ul><ul><li>No limits on number of sectors (depending) </li></ul></ul></ul>
  22. 22. Sectors and Tracks
  23. 23. Overview of Computer Hardware <ul><li>Magnetic Disk </li></ul><ul><ul><li>Used the most for permanent storage in computers </li></ul></ul><ul><ul><li>In principal, stores data pretty much the same way as tapes </li></ul></ul><ul><ul><ul><li>Magnetic coating covers the disk </li></ul></ul></ul><ul><ul><ul><li>Takes magnetic charge to represent data </li></ul></ul></ul><ul><ul><li>Divided into tracks and sectors </li></ul></ul><ul><ul><ul><li>Tracks are concentric circles on the disk </li></ul></ul></ul><ul><ul><ul><li>Sectors divide the disk into pie-shaped areas </li></ul></ul></ul><ul><ul><ul><li>Data fills all track within one sector </li></ul></ul></ul><ul><li>All tracks can store the same number of bits !!! </li></ul><ul><ul><li>more compact towards the center (higher density) </li></ul></ul>
  24. 25. R/W Head <ul><li>R/W head can move to any position (sector, track) on the disk  random access </li></ul>
  25. 26. Overview of Computer Hardware <ul><li>Comes in two forms : </li></ul><ul><ul><li>Portable </li></ul></ul><ul><ul><ul><li>Floppy disks </li></ul></ul></ul><ul><ul><ul><ul><li>Because they are flexible (easily bent) </li></ul></ul></ul></ul><ul><ul><ul><ul><li>3.5’’ </li></ul></ul></ul></ul><ul><ul><ul><ul><li>1.44 MB </li></ul></ul></ul></ul>
  26. 27. Calculations <ul><li>Information Given : </li></ul><ul><li>A magnetic disk is labeled M </li></ul><ul><li>Able to write on 1 side. </li></ul><ul><li>40 sectors </li></ul><ul><li>60 tracks </li></ul><ul><li>1 cluster = 2 sector track </li></ul><ul><li>I sector-track=512 byte </li></ul>
  27. 28. Calculate <ul><li>The number of sector-track on one side? </li></ul><ul><li>40 x 60 = 2400 sector-track </li></ul><ul><li>The number of sector-track on both sides? </li></ul><ul><li>2400 sector-track because the other side = 0 </li></ul><ul><li>How much can be stored on one side? </li></ul><ul><li>2400 x 512 byte = 1228800 bytes </li></ul><ul><li>How much can be stored on both sides? </li></ul><ul><li>1228800 bytes </li></ul>
  28. 29. Calculate <ul><li>How many cluster on one side? </li></ul><ul><li>2400/2= 1200 clusters </li></ul><ul><li>How many cluster on entire disk? </li></ul><ul><li>1200 clusters </li></ul><ul><li>What is the total track in the entire disk? </li></ul><ul><li>60 tracks </li></ul>
  29. 30. Exercise in class <ul><li>Information Given : </li></ul><ul><li>A magnetic disk is labeled J </li></ul><ul><li>Able to write on 2 sides. </li></ul><ul><li>80 sectors </li></ul><ul><li>90 tracks </li></ul><ul><li>1 cluster = 2 sector track </li></ul><ul><li>I sector-track=512 byte </li></ul>
  30. 31. Calculate : <ul><li>The number of sector-track on one side? </li></ul><ul><li>The number of sector-track on both sides? </li></ul><ul><li>How much can be stored on one side? </li></ul><ul><li>How much can be stored on both sides? </li></ul><ul><li>How many cluster on one side? </li></ul><ul><li>How many cluster on entire disk? </li></ul><ul><li>What is the total track in the entire disk? </li></ul>
  31. 32. Overview of Computer Hardware <ul><li>Fixed </li></ul><ul><ul><li>Hard disks </li></ul></ul><ul><ul><li>Single (PCs) or multiple (~ 10 to 12) </li></ul></ul><ul><ul><li>Multiple GBs per disk </li></ul></ul><ul><ul><li>Diskettes have 135 tracks per inch and 18 tracks </li></ul></ul><ul><ul><ul><li>HDs have 1000s of tracks per inch and 64 tracks </li></ul></ul></ul><ul><ul><li>R/W does not touch the surface but floats right above it  Rotate 100 times faster than diskettes </li></ul></ul><ul><ul><li>They are sealed so that no dirt comes between R/W head and disk (corrupts data) </li></ul></ul>Disk Pack
  32. 33. Overview of Computer Hardware <ul><li>Compact Disks (CDs) </li></ul><ul><ul><li>Optical disk </li></ul></ul><ul><ul><li>Data stored like magnetic disks (series of dots on tracks) </li></ul></ul><ul><ul><ul><li>Now we BURN the dots (rather than magnetic charges) as pits on the surface </li></ul></ul></ul><ul><ul><ul><li>A laser detects those pits as 0s </li></ul></ul></ul><ul><ul><ul><li>Data spans a track of the disk (not sectors) </li></ul></ul></ul><ul><ul><ul><li>Pits gives the advantage of more density of storage </li></ul></ul></ul><ul><ul><ul><ul><li>600 MB to 10 GB </li></ul></ul></ul></ul><ul><ul><ul><li>Most CDs are Read-only (because of the burning) </li></ul></ul></ul><ul><ul><ul><li>Some optical drives do allow for re-burning of surface after smoothing out the pits </li></ul></ul></ul>
  33. 34. Cutaway View of a Multi-Platter Hard Disk Drive
  34. 35. Simplified View of Disk Track and Sector Organization <ul><li>An integral number of sectors are recorded around a track </li></ul><ul><li>A sector is the unit of data transfer to or from the disk </li></ul>
  35. 36. Simplified View of Individual Bits Encoded on a Disk Track <ul><li>Inside tracks are shorter & thus have higher densities or fewer words </li></ul><ul><li>All sectors contain the same number of bytes </li></ul><ul><ul><li>Inner portions of a platter may have fewer sectors per track </li></ul></ul><ul><li>Small areas of the disk are magnetized in different directions </li></ul><ul><li>Change in magnetization direction is what is detected on read </li></ul>
  36. 37. Photo of Disk Head, Arm, Actuator Actuator Arm Head Spindle Platters {
  37. 38. Disk Device Terminology <ul><li>Several platters , with information recorded magnetically on both surfaces (usually) </li></ul><ul><li>Actuator moves head (end of arm ,1/surface) over track ( “seek” ) , select surface , wait for sector rotate under head , then read or write </li></ul><ul><ul><li>“ Cylinder ”: all tracks under heads </li></ul></ul><ul><li>Bits recorded in tracks , which in turn divided into sectors (e.g., 512 Bytes) </li></ul>Platter Outer Track Inner Track Sector Actuator Head Arm
  38. 39. DVD <ul><li>Replacing CD-ROM </li></ul><ul><li>Holds much larger amount of information (such as movie) </li></ul><ul><li>Also does not work on library computers </li></ul>
  39. 40. Zip Disk <ul><li>Similar to floppy </li></ul><ul><li>Thicker form </li></ul><ul><li>Holds more information </li></ul><ul><li>Available on some library computers </li></ul><ul><li>Also becoming obsolete </li></ul>
  40. 41. Flash Drive <ul><li>Most recent widely used storage system </li></ul><ul><li>Very portable, often worn like jewelry </li></ul><ul><li>128-512 Megabytes most common sizes </li></ul>
  41. 42. Classes for beginners <ul><li>No particular order in this group </li></ul><ul><li>Free! </li></ul><ul><li>Can take more than once </li></ul><ul><ul><li>Basic Skills </li></ul></ul><ul><ul><li>Internet Level 1 </li></ul></ul><ul><ul><li>MS Word Level 1 </li></ul></ul>
  42. 43. Time to practice a bit <ul><li>Advance twice to end slide show </li></ul><ul><li>If time allows you will practice a bit to see what it is like to take our classes </li></ul>
  43. 44. The End <ul><li>Zainudin Johari </li></ul><ul><li>B Sc (Hons ) Computer Science, UPM </li></ul><ul><li>M Sc Information Systems, UPM </li></ul>

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