TRINITY INSTITUTE OF PROFESSIONAL STUDIES

Sector – 9, Dwarka Institutional Area, New Delhi-75Affiliated to Institution of G.G.S.IP.U, Delhi

IT BasicsKeywords : Memory, CPU

B.COM INTRODUCTION TO INFORMATION

TECHNOLOGY 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 to 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 definitely• 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