Lecture 01 b

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Lecture Objectives

Computer Hardware DetailsFour Types of Computers

Computer Networks

Network Classifications

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Computer Hardware Details

Computer Classification BasisProcessing Speed – instructions/ second or MHz, GHz

Data Storage Capacity – Total bytes available

Cost

Size

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Types of Computers

Supercomputers

Mainframe computers

Minicomputers

Microcomputers

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Super Computers

Most superior on all levelsFastest

Capable of processing at 120-200 MIPS (Millions of Instructions Per Second)/ expected to keep increasing

Most Spacious for Data storageCapable of saving data in trillion of bytes (up to 30 TB).

Most costlyPrices begin at about $4 million.

LargestOccupy large halls

Application Areas

-Primarily used for very demanding applications, where huge amount of data input is involved.

•Number Crunching•Weather Forecasting•Aircraft design•Nuclear Research•Seismic Analysis•Space Program

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Mainframe Computers

A bit moderate as compared with Super Computers.

First developed computers in the history (50’s)

Specially wired for connecting 100’s of terminals.

Speed Capable of processing at 10’s of MIPS.

Capacity for Data storageCapable of saving data in trillion of bytes (up to 50-100 TB).

Cost Range$100,000 or more.

SizeOccupy large rooms

Application Areas

-Primarily used by medium to large size companies as a central computing resource.

For large processing applications in business areas such as - accounting, - sales and marketing, production, and - human resources.

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Mini Computers

Smaller & cheaper than main frame in its capabilities.

Came in 70’s to offload the overloaded Mainframes.

Technological advancements result in increased capabilities & reduced prices.

New versions are called Mid Range Computers.

Speed -Comparable to main frame now.

Capacity for Data storageCapable of saving data in trillion of bytes (up to 4-5 TB).

Application Areas

-Primarily used by sub-departments of companies to offload the company mainframe’s work.

e.g. an inventory department might use a mini to provide better control of stock and to make predictions about future needs.

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Micro Computers

Introduced in early 80’s.

Can be sub-classed on speed and portability.SUPERMICROS

High powered (near to minis)

Used a different processing approach then standard Micros (RISC)

Example: Workstation Micros (Network server, high quality graphics etc.)

-Leading Manufactures for workstations are SUN Microsystems (SPARC) Application Areas

-Popularly used as a server machine in a networked environment.

-Widely use for business applications.

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Micro Computers

DESKTOP MICROSKeep on increasing in processing power etc.Mostly in a personal access.Can run many applications at a time (needs operating system support).

PORTABLE MICROSVery Compact & Lightweight.As powerful as desktops.Used by mobile usersLaptop – about 11 lbs/ can be fitted inside an airplane tray.Notebook – nearly 7 lbs/ can be accommodated in a brief case.Palmtop – 2/3 lbs / can fit into a pocket or purse. (Poqet/ HP)

– Capabilities: Hand-writing recognition, personal organization tools, travel information, communication means.

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Microcomputers

Least powerful

Widely used

Four typesDesktop

Notebook or laptop

Tablet PC

Handheld

Application Areas

-Almost every where (because of ever falling cost).

-Education -Entertainment -Businesses -Mobile Professions (Salespersons, Field data collecting staff etc.)

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Micro Computer Hardware

A large diversity of devices are in use.

Four categories.System Unit

Input/ Output Devices

Secondary Storage Devices

Communication Devices

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…Micro Computer Hardware

System Unit Corresponds to the Circuit board housed inside the computer cabinet.Also termed as Mother Board.Every other device has a connection with this circuitry.Two main components are:

Microprocessor Chip Controls and manipulates data to produce information.

Memory Chip(s) (RAM) Holds data & program instructions temporarily (volatile).

Video Clip: How to build a PC? Part I & II (Available on WebCT)

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…Micro Computer Hardware

Input/ Output DevicesAll devices (a variety of them) which do the conversion from human understandable to computer understandable data & vice versa.

Keyboard, mouse – most common input devices.

Monitors, printers – most common output devices.

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…Micro Computer Hardware

Secondary Storage DevicesHolds data & program (like RAM)Permanently store (non-volatile) the contents (unlike RAM).Floppy

Magnetic media (small capacity/ slower in access) Hard disk

Metallic media (large capacity/ more fast accessible) Optical disks

Laser technology (largest capacity/ fast access).CD-ROMS (only readable)/ CD-RW (read/write)/ DVD (Digital Versatile Discs)

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…Micro Computer Hardware

Communication DevicesControls the communication between Computers.Sends/ Receives data or program bits on different media like

telephone lines

coaxial cable (Chapter 7 pg155)fiber optics cable Satellite links

Modem is the most widely used (Uses telephone lines).

A modem is capable of (Chapter 7 pg153)MODulate (data to telephone signals) and DEModulate (telephone signals to data)

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Connectivity & InternetConnecting computers extends their usability to enormous extent.

Information sharing opens new horizons in computing.

Connectivity results in Computer Networks.

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Computer Network Classification

Classified on the basis of geographical boundaries.

LAN - within a building

MAN – across buildings

WAN – country wide/ world wide

(Chapter 7 pg165)

LAN Example

WAN Example