TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75Affiliated Institution of G.G.S.IP.U, Delhi
By:RUCHIKA BAJAJ
ASSISTANT PROFESSOR(IT)
INTRODUCTION TO INFORMATION TECHNOLOGY
B.COM Into to IT BCOM 107
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
Computer
Hardware Software
ApplicationSoftware
SystemSoftware
CPU Memory I/O Etc.
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
Fig: Computer
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
MOTHERBOARD
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
CPU
RAM
Memory chips
TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75Affiliated Institution of G.G.S.IP.U, DelhiRAM & ROM
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
SRAM
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
DRAM
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
Ports
CPU
RAM
Diskcontroller
Graphicscard
Soundcard
Networkcard
Printer
Mouse
Keyboard
Modem Monitor
Speakers
bus
Computer
Fig: Schematic Diagram of a Personal
Computer...
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
Secondary Storage
• Stores information
• Non-volatile, permanent storage
• Characteristics
– Media
– Capacity
– Access time
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
Secondary Storage Devices
Two major types of secondary storage device 1. Serial Devices
– Magnetic tapes (very fast sequential access)
2.Direct Access Storage Devices (DASDs)– Magnetic Discs
Hard disks (high capacity, low cost, fast) Floppy disks (low capacity, lower cost, slow)
– Optical Disks CD-ROM = (Compact disc, read-only memory
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
Limitation of Secondary Devices
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
Magnetic Tape
• Sequential access
• Commonly used for backing-up data
• Very large capacity
• Types of magnetic tape
– Tape cartridges
– Magnetic tape reels
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
Magnetic Tape
TRINITY INSTITUTE OF PROFESSIONAL STUDIESSector – 9, Dwarka Institutional Area, New Delhi-75
Magnetic Tape
• Plastic ribbon 1/2 inch or ¼ inch wide• 50 to 2400 feet long• Coated with magnetic material such as iron oxide
or chromium dioxide.• Data stored in form of tiny magnetized(1) or non
magnetized spots(0) • Can be erased and reused in definately• Information can be read many times without
affecting data
Magnetic Tape• What is magnetic tape?
• Thin layer of material capable of storing a magnetic signal
• Usually contains Iron Oxide
• Protected by backing layer called the “Substrate”
Examples of Magnetic Media
• Some you are probably familiar with:• Cassette tapes• VHS video tape• Computer Tape• 8-track• DAT
Magnetic Tape Types
• Tape cartridges– Backup tape for microcomputer – Capacities range from 120 MB to 5 GB– Digital audio tape (DAT)
• Tape reels– Minicomputer and mainframe– 1/2 inch wide and 1/2 mile long– Stores 1600 to 6400 cpi
