This document discusses computer hardware and classifications. It covers four types of computers: supercomputers, mainframe computers, minicomputers, and microcomputers. It then provides details on microcomputer hardware components including the system unit, input/output devices, secondary storage devices, and communication devices. Finally, it briefly introduces computer networks and their classification based on geographical boundaries as local area networks (LAN), metropolitan area networks (MAN), and wide area networks (WAN).

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