1. 1-1
Lecture Objectives
Computer Hardware Details
Four Types of Computers
Computer Networks
Network Classifications

2. 1-2
Computer Hardware Details
Computer Classification Basis
Processing Speed – instructions/ second or
MHz, GHz
Data Storage Capacity – Total bytes
available
Cost
Size

3. 1-3
Types of Computers
Supercomputers
Mainframe computers
Minicomputers
Microcomputers

4. 1-4
Super Computers
Most superior on all levels
Fastest
Capable of processing at 120-200 MIPS (Millions
of Instructions Per Second)/ expected to keep
increasing
Most Spacious for Data storage Application Areas
Capable of saving data in trillion of bytes (up to
30 TB). -Primarily used for very
demanding applications,
Most costly where huge amount of data
Prices begin at about $4 million. input is involved.
Largest •Number Crunching
Occupy large halls •Weather Forecasting
•Aircraft design
•Nuclear Research
•Seismic Analysis
•Space Program

5. 1-5
Mainframe Computers
Application Areas
• A bit moderate as compared with Super -Primarily used by medium to large
Computers. size companies as a central
• computing resource.
First developed computers in the history
(50’s) For large processing applications
• Specially wired for connecting 100’s of in business areas such as
- accounting,
terminals.
- sales and marketing, production,
• Speed and
Capable of processing at 10’s of MIPS. - human resources.
• Capacity for Data storage
Capable of saving data in trillion of bytes
(up to 50-100 TB).
Cost Range
$100,000 or more.
Size
Occupy large rooms

6. 1-6
Mini Computers
Application Areas
• Smaller & cheaper than main frame in -Primarily used by sub-
its capabilities. departments of companies to
offload the company
• Came in 70’s to offload the overloaded mainframe’s work.
Mainframes. e.g. an inventory department
• Technological advancements result in might use a mini to provide
better control of stock and to
increased capabilities & reduced prices. make predictions about future
• New versions are called Mid Range needs.
Computers.
• Speed -Comparable to main frame now.
• Capacity for Data storage
Capable of saving data in trillion of bytes
(up to 4-5 TB).

7. 1-7
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.

8. 1-8
Micro Computers
DESKTOP MICROS
Keep on increasing in processing power etc.
Mostly in a personal access.
Can run many applications at a time (needs
operating system support).
PORTABLE MICROS
Very Compact & Lightweight.
As powerful as desktops.
Used by mobile users
Laptop – 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,

9. 1-9
Microcomputers
Least powerful
Widely used
Four types
Desktop
Notebook or laptop
Tablet PC Application Areas
-Almost every where (because of ever falling cost).
Handheld
-Education
-Entertainment
-Businesses
-Mobile Professions (Salespersons, Field data
collecting staff etc.)

10. 1-10
Micro Computer Hardware
A large diversity of devices
are in use.
Four categories.
System Unit
Input/ Output Devices
Secondary Storage
Devices
Communication Devices

11. 1-11
…Micro Computer Hardware
Video Clip: How to build a PC? Part I & II
(Available on WebCT)
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).

12. 1-12
…Micro Computer Hardware
Input/ Output Devices
All 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.

13. 1-13
…Micro Computer Hardware
Secondary Storage Devices
Holds 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)

14. 1-14
…Micro Computer Hardware
Communication Devices
Controls 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)

15. 1-15
Connectivity & Internet
Connecting computers
extends their usability to
enormous extent.
Information sharing opens
new horizons in computing.
Connectivity results in
Computer Networks.

16. 1-16
Computer Network Classification
Classified on the basis of
geographical boundaries.
LAN - within a building
MAN – across buildings (Chapter 7 pg165)
WAN – country wide/ world wide
LAN
Example
WAN Example