Data- row facts Information - convert to more useful & meaningful form Data processing is just like making a cake

DataInformationProcess Data (row facts) Numbers, words, image, sound Eg: List of my friends Information (Processed data or data has been convert to more useful & meaningful form Eg: list can arrange in ascending order (A to Z )

InputOutputProcess Input Devisers Output Devisers

Please correct the pg 4 Data / Instructions Command /Signal Flow Block diagram Of computer System

Input Devises Keyboard, Mouse Light pen Digital Camera Scanner Joy stick Fingerprint scanner Touch screen Magnetic strip reader Graphic tablets Microphone Optical character recognition (OCR) Video recognition

Keyboard Convert letters, numbers and other characters into electronic signals 1.Typing keys 2.Numeric keypad 3.Function keys 4.Control keys

QWERTY is the most common modern-day keyboard layout The name comes from the first six keys appearing on the top left letter row of the keyboard and read from left to right: Q-W-E-R-T-Y. The QWERTY design is based on a layout created for the typewriter

Mouse Pointing device 1.Ball underneath rolls 2.Laser to sense the motion

PS 2 Mouse USB Mouse

Light pen Pointing device Light sensitive pen like devise ( help to draw )

Digital Camera No film roll Capturing videos Photos can directly move into the computer without scanning

Scanner Convert text, drawing, photos in to digital form that can Stored and edit in computer

Joy stick Joy stick (Pointing device) Pointing devise Help to play video games

Fingerprint scanner Pointing device Use to scene finger prints for security reasons, or time attendance

Touch screen (Pointing device) Display screen that receives input from the touch of a finger( ATM screens in banks) (Input and output both)

Magnetic strip reader Used as credit card, railway tickets, time attendance, debit cards

trackball

Magnetic Ink Character Recognition, (MICR) MICR codes can be easily read Cheque numbers

Optical character recognition,(OCR) Optical character recognition, conversion of images of text into characters

OMR- Optical mark recognition Optical mark recognition is the process of capturing human-marked data from document forms such as surveys and tests.( Eg: MCQ

barcode reader (or barcode scanner)

Graphic tablets (Pointing device) Like electronic tracing paper Use for CAD

Microphone Input sound

O UTPUT D EVICES

MONITOR (Visual Display Unit ) The computer monitor, screen or VDU (Visual Display Unit) is the most common output device. Advantages - relatively cheap and reliable, can display text and graphics in a wide range of colours. They are also quiet and do not waste paper. Disadvantages - no permanent copy to keep and unsuitable for users with visual problems.

MONITOR Cathode ray tubes (CRTs) Liquid crystal displays (LCDs)

CRT Less Sharpness than LCD Takes large space than LCD Flicker No limited viewing angle cheaper than LCD large energy consumption when compare with LCD CRT monitor's response time is negligible

LCD Sharp pictures Takes very little space( Slim) Flicker-free screens are easy on the eyes limited viewing angle Fairly expensive Use less energy and generate less heat than CRTs Slower response time (response time is the time it takes for the pixel to update the colours you see on screen.)

Speakers and head phones Taking sound out of the computer Some computer displays have rather basic speakers built-in. Laptops come with integrated speakers

impact vs non impact printer

daisywheel BM9JELUYQhttp:// BM9JELUYQ Daisy wheel printing is an impact printing technology invented in

Dot-Matrix printer Less expensive Noisy Producing the image by striking paper through the ribbon Low quality print out Very slow

Ink Jet-printer Cheaper than laser Not that noisy Technology-ink flowing through the appropriate nozzles. Quality than dot matrix Faster than dot matrix

Laser-printer Expensive Very silent in operation Work with toners Very High quality print outs Very fast

plotter

projector, a device that projects an image on a surface

SECONDARY STORAGE Hard Disk Floppy Disk Optical Disk Storage Magnetic tape

Hard Disk non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces

Hard Disk

Floppy Disk

Floppy Disk 1.44 Mb Disk hidden in a plastic jacket 5¼-inch (133 mm), and the newest and most common 3½-inch (90 mm) Portable an outdated medium

Zip Disks Zip disk Mb better than floppy portable and removable An outdated medium

Optical Disk Storage CD MB DVD-2GB-8GB optically written on its surfers CDROM-compact disk read only memory WORM-write once read only memory Rewritable CD. DVD - Digital video disk /(digital versatile disc) same dimensions as a CD but stores up to 6 times as much information

DVD Digital Versatile Disk (DVD)

Magnetic tape Similar to audiotapes store data in serial manner Accessing speed is Low Can store very large capacity of data (used for back ups )

Main memory

RAM Random access memory Storing programs witch is currently running and data witch is being processed Volatile memory where the information is lost after the power is switched off

ROM Read only memory Contents permanently etched into the memory chip at the manufacturing stage ROM stands for Read Only Memory, and is a memory chip which only allows data to be read from it, and will not allow data to be written onto it Non Volatile memory

Cache memory Very fast memory, that is use to improve the speed of the PC It act as an intermediate store between the CPU and main memory

Computer Ports

PS/2 connector A mini DIN plug containing 6 pins. Developed by IBM for connecting the keyboard (purple ) and mouse (green ) Shape -Round

Parallel port connector for scanners and printers The 25-pin port

Serial Port A 9-pin D-type connector meeting EIA-232 standard. Possibly used to connect some trackballs, mice, modems and monitors.

VGA port the 15-pin plugs and sockets that connect the computer to the monitor. used to connect a monitor

USB- Universal Serial Bus A single USB port can be used to connect up to 127 peripheral devices, FAST Plug and Play Hot plugging /hot swapping

Hot plugging /hot swapping. The ability to add and remove devices to a computer while the computer is running and have the operating system automatically recognize the change. Two external bus standards -- Universal Serial Bus (USB ) and IEEE support hot plugging. This is also a feature of PCMCIA. Hot plugging is also called hot swapping

Ethernet (or Network) Port used to connect with internet /network

Hardware The term hardware describes the physical parts of your computer which you can physically touch or see such as your monitor, case, disk drives, microprocessor and other physical parts.

Software

software collection of computer programs, procedures and documentation that perform some tasks on a computer system.

Hardware System Software Application Software USER

Application Software examples of software applications are word processors, spreadsheets, and media players, database applications.

System software System software such as operating systems, which interface with hardware to provide the necessary services for application software,