![2.1.1 Keyboard :
•Most Common Device
•Numbers (0.9), Characters (a-z, A-Z), Alpha Numeric (Number and
Charecter), Special Keys (Up,Down,Shift,Ctr ), Punctuation Keys (, . > < ? @ ! $
& ^ ( ) [] {}), Functional keys (F1 – F12)
•101 Keys / 104 Keys
• Converts the ASCII CODE for each Keys
•ASCII CODE American Standard Code of Information Interchange](https://image.slidesharecdn.com/chapter2inputoutputmemeorydevices1-230727050623-e8250435/85/CHAPTER-2-INPUT-OUTPUT-MEMEORY-DEVICES-1-pptx-4-320.jpg)
CHAPTER 2 INPUT OUTPUT MEMEORY DEVICES (1).pptx
- 1. CHAPTER 2 INPUT (I/P), OUTPUT (O/P), MEMORY (M/Y) DEVICES By:Vinayak Badiger Dept of Commerce DGI Terdal Contact: +91 815582503
- 2. 2.1 INPUT DEVICES Input = Feed Device = Electronic equipment) Input Device – Device used to accept Data and Instructions from user •Used to feed data and instructions into computer •Converts Data – Recognised by computer (0 &1) Examples : Keyboard, Mouse, Trackball, Joystick, Scanner, Light pen, Barcode Reader, OCR,OMR, MICR etc.
- 3. Trackball – Ball used in mouse for pointing Light Pen – Used in light sensitive Devices to select, draw and interact OCR - Optical Character Recognition – Recognise the Character OMR – Optical Mark Recognition MICR – Magnetic Inc Character Recognition – To Scan Digital Printed code on cheque (Bottom)
- 4. 2.1.1 Keyboard : •Most Common Device •Numbers (0.9), Characters (a-z, A-Z), Alpha Numeric (Number and Charecter), Special Keys (Up,Down,Shift,Ctr ), Punctuation Keys (, . > < ? @ ! $ & ^ ( ) [] {}), Functional keys (F1 – F12) •101 Keys / 104 Keys • Converts the ASCII CODE for each Keys •ASCII CODE American Standard Code of Information Interchange
- 6. Types of Keyboard 1.Standard Keyboard •Basic Layout •105/108 keys •QWERTY in First row 2.Ergonomics •Method to reduce stress on mussels on repetitive •Optimize the posture and technique while working
- 7. 3. Wireless keyboard ● No Physical connection to computer (wire) ● Uses ● Bluetooth ● InfraRed (IR) 4. Virtual Keyboard ● Software ● Keyboard displayed on screen ● Controlled by Mouse / wire touch screen
- 8. 5. Compact Keyboard ● Slim ● No Numeric Keypad ● Used in Laptops
- 10. 2.1.2 Mouse • Control the Movement of the cursor on Display • MOUSE – Mechanically Operated User Serial Engine • Pointing Device • Small device navigate on Flat Surface • Contain Ball/IR rays inside touches the pad through hole at bottom Two Types • Mechanical – Not accurate (Rubber Ball) • Optical – Accurate (Laser)
- 12. 2.1.3 Joystick •Stick Pivots on base reports its angle and direction •Moves in all Four Direction •Used in ❏ Games ❏ Cranes ❏ Underwater Unmanned Vehicles ❏ Surveillance Camara •
- 13. 2.1.4 Optical Mark Reading and Recognition (OMR ) ❖ Reads Pencil Marks and convert into digital form ❖ Pre printed forms are designed with box ❖ Dark Ink or Pencil to fill ❖ Read by Reader ❖ Used in Objective type of answer papers for evaluation
- 14. 2.1.4 OCR Optical Character Recognition ❏ Recognises Alphabetic and Numeric ❏ No special Inc required ❏ Can be edited (Width, Height, Depth) ❏ Used in Credit card Billing, Large Post Office(PIN CODE) to sort geographically
- 15. 2.1.4 MICR (Magnetic Ink Character Recognition) ❏ Shape of the character recognised by the magnetic charge ❏ Used in Bank to Process Cheque ❏ Eliminates manual error ❏ Save Time ❏ Increases Accuracy
- 16. 2.2 Introduction to Output devices ● Result/Information ● After Processing ● O/P must be human understandable format Most Commonly Used ○ Monitors ○ Printers
- 17. 2.2.1 Monitor ● Used output device ● Also called as Display screen / Visual display unit(VDU) ● VDU = Display of data ● Monitors are connected with the computer
- 18. ● The smallest dot = pixel ● Increase in the no of pixel = Increase in Resolution ● Resolution = Quality of Display ● 640x480, 1024x768 ● Size is Measured Diagonally 12",14",17",19", 21"
- 19. Printer ● Prints text / Images on paper or other media ● Print = Hard copy’ Types (Speed & Quality) 1. Impact printers - Striking device against Inked Ribbon 2. Non-impact printers
- 20. Characteristics of impact printers ● Physical contact with the paper ● Multiple copies = Carbon = Many layers of paper ● Very noisy (1) ● Slow ● No Transparencies ● Speed = Characters per seconds (cps)
- 21. Characteristics of Non-impact printers ● Uses ink or semi-solid ink ● Both cartridge and flow of ink is controlled by the processors ● Faster, Different colour/font/size ● Noiseless ● High-quality graphics ● Support the transparencies
- 22. ● No impact on paper ● Measured in dots per inches (dpi) ● Speed = Number of pages per minute (ppm) ● The size of the printing various A4, A3, A2, A0 and Jumbo size
- 23. Line Printer ● High-speed printers (One line at a time) ● Print 150 lines to 3000 lines/min ● Supports for only one font ● No Graphics ● Low quality ● Noisy to operate ● Print large volume
- 24. Dot Matrix Printer ● Most popular serial printer is the dot matrix printer ● It prints one line of 8 or 14 points at a time ● Print head moves across a line ● Slow ● Speed 300 characters per second ○ VRL (Booking Ticket ○ Parcel Booking reciept
- 25. Thermal Printer ● Electrically heated pins against special heat-sensitive paper ● Inexpensive ● Fax machines ● Darken over time (sunlight and heat) ● Fade after a week or two ● Poor quality print.
- 26. Laser Printers ● Use a laser beam and dry powdered ink ● Ggood Quality of graphic images ● Quality = dots per inch (dpi) ● Resolutions range from 300 dpi to 1200 dpi
- 27. Inkjet Printers ❏ Uses colour cartridges which combine magenta, yellow and cyan,black inks to create colour tones ❏ Spraying ionizing ink at paper ❏ Magnetized plates in the ink’s path direct the ink onto the paper in the described shape
- 28. 2.2.2.8 Plotter Printers ❏ Draw lines using a pen ❏ Draw continuous lines ❏ Multicolor plotters use different-colored pens ❏ More expensive than printers ❏ Used in engineering applications
- 29. 2.2.3 Speakers Analog/digital => audible frequency in the speaker => Voice output (audio data) speech synthesizer => voice output Used in many places like airlines, banks, automatic telephone enquiry system, music/ songs
- 30. 2.3 Introduction to Memory devices ❏ Essential part of the computer ❏ Storage part of the computer ❏ Memory = Main memory ❏ For Future Use ❏ Storage = Large Volume (Hard Disc) Two Types 1. Primary memory 2. Secondary memory
- 32. 2.3.1 Primary Memory Memory =Main memory = ‘chip’ (Integrated Circuit) Storage = disks, CD's, floppies or tapes, pendrive
- 33. There are different types of memories: 1. Read Only Memory (ROM) 2. Programmable Read-Only Memory (PROM) 3. Erasable Programmable Read-Only Memory (EPROM) 4. Electrically Erasable Programmable Read-Only Memory (EEPROM)
- 34. Read Only Memory Burnt (pre-recorded) at manufacturing time Once data written into a ROM chip cannot be erased Data stored permanently (non volatile)
- 35. Programmable Read Only Memory - PROM Written only once Not burnt at the manufacturing time Programmed using PROM programmer or a PROM burner PROM is also a non-volatile memory
- 36. Erasable Programmable Read Only Memory – EPROM ❏ Erased and re-programmed using a special PROM programmer ❏ non-volatile memory ❏ Ultraviolet light is used to erase the contents of the EPROM
- 37. Electrically Erasable Programmable Read Only Memory – EEPROM ❏ Similar to EPROM ❏ Data erased by exposing it to an electrical charge ❏ Non-volatile ❏ Not as fast as RAM or other types of ROM
- 38. Random Access Memory - RAM ❏ Most common type of memory found in the modern computers ❏ Main store = Program gets stored temporary ❏ CPU fetches program instructions from the RAM ❏ CPU store results stores in RAM ❏ Switch OFF a computer Data gets erased ❏ Volatile
- 40. 2.3.2 Secondary Memory ● Computer need to store data programs ● Primary memory is volatile =>Secondary storage ● Non Volatile ● Large amount of data storage for long period of time ● Example ○ hard disks ○ Magnetic tapes ○ Floppy disks ○ CD-ROM
- 41. ○ The average time required to reach a storage location and obtain its contents is called its access time ○ Access time = Seek time + Transfer time
- 42. Hard Disk ❏ Its is magnetic disk on which you can store computer data ❏ Direct-access storage medium ❏ Store data randomly ❏ High speed rotating surfaces coated with a magnetic recording medium ❏ Write Head ❏ Read Head ❏ Each ring(called a track) ❏ Track Divided into a number of sectors Data elements (bytes or characters)
- 44. ● The smallest unit read/write in disk is a sector ● Storage capacity of the disk = Number of tracks * number of sectors * bytes per sector * number of read/write heads ● Disk rotation speed 80,000 rpm
- 45. Magnetic Tape ● Thin tape with a coating of a fine magnetic strip (plastic) ● Bits recorded as magnetic spots on the tape, several tracks ● 7 - 9 bits recorded simultaneously ● Read/write heads are mounted one in each track
- 46. Floppy Disk ● Thin circular disk ● Soft magnetic disk ● Flexible or semi-rigid protective jacket ● Rotation speed 360rpm ● read/write head makes physical contact with disk ● 3.5" in size ● Hold 1.44 MB of data ● ‘write protected’ ● Slower to access than hard disks ● Less storage capacity ● Less expensive and is portable ● It can be accessed randomly.
- 47. ● Optical Disk ● Data can be read ● Written by lasers ● Random access storage medium (Can be easily read from any point on the disk) ● CD-ROM = Compact Disk - Read Only Memory
- 49. DVD ● Digital Video Disc ● Advances in optical disc technology ● Stores Music, Data ● Digital Versatile Disc
- 50. BLUE ray disk ● BD ● Thickness of 1.1mm ● Recording capacity 23.3GB/25GB/27GBa
- 51. Portable storage device (PSD) ● Small hard drive ● Fixed size hard drives of 256GB, 320GB,500Gb,1Tb,2Tb etc ● Expandable to unlimited storage capacity
- 52. 2.3.3 Cache Memory ● Small amount of high-speed memory ● Between primary memory and CPU (processor) ● Two levels L1 and L2 ○ L1 present inside CPU ○ L2 present on mother board ○ Holds the most recent data/instructions