This document provides an overview of computer systems, including: - The definition of analog and digital computers, with analog using a range of values and digital using discrete two-value digits. - Different types of computers for individual use like desktops, notebooks, tablets, handhelds, and smartphones. - Computers for organizations including network servers, mainframes, minicomputers, and supercomputers. - The large societal impact of computers and their uses in homes, education, small business, industry, government, and health care.

1. Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
McGraw-Hill Technology Education
Chapter 1A
Introducing Computer
Systems

2. 1A-2
The Computer Defined
• Electronic device
• Converts data into information
• Modern computers are digital
– Two digits combine to make data
• Older computers were analog
– A range of values made data

3. Analog Computer:
• Analog Computer:
• It works with continuous values, i.e they process
continuous data.
• The speed of such computers is less than that of
digital computers.
• It has very less memory and can store limited amount
of data.
• The results given by analog computers have very less
accuracy.
• Examples includes analog clock and thermometer.
1A-3

4. Digital Computer:
• Digital Computer:
• They work with discrete values, i.e they process
discrete data.
• The speed of digital computers is more in comparison
to analog computers.
• It has more memory space, hence stores large
amounts of data.
• It has two steps: On and Off.
• It is more reliable.
• It provides great performance.
• Its processing speed is high.
• Examples include laptop, digital camera, digital
watches.
1A-4

5. 1A-5
Computers For Individual Use
• Desktop computers
– The most common type of computer
– Sits on the desk or floor
– Performs a variety of tasks
• Workstations
– Specialized computers
– Optimized for science or graphics
– More powerful than a desktop

6. 1A-6
Computers For Individual Use
• Notebook computers
– Small portable computers
– Weighs between 3 and 8 pounds
– About 8 ½ by 11 inches
– Typically, as powerful as a desktop
– Can include a docking station

7. 1A-7
Computers For Individual Use
• Tablet computers
– Newest development
in portable
computers
– Input is through
a pen
– Run specialized
versions of office
products

8. 1A-8
• Handheld computers
– Very small computers
– Personal Digital Assistants (PDA)
– Note taking or contact management
– Data can synchronize with a desktop
• Smart phones
– Hybrid of cell phone and PDA
– Web surfing, e-mail access
Computers For Individual Use

9. 1A-9
Computers For Organizations
• Network servers
– Centralized computer
– All other computers connect
– Provides access to network resources
– Multiple servers are called server farms
– Often simply a powerful desktop

10. 1A-10
Computers For Organizations
• Mainframes
• The size of the disk is large.
• They have large memory storage.
• The speed of processing is fast in
comparison to minicomputer.
• They are more expensive.
• The first successful mainframe
computer was invented by IBM.
• They can be used to work with
thousands and millions of users
simultaneously.
• Their processing speed is in the
range of 3 to 4 MIPS and can go up
to 100 MIPS

11. 1A-11
Computers For Organizations
• Minicomputers
– Called midrange computers
• The size of disk is small.
• They have less memory storage and processing
speed is less in comparison to mainframes.
• It is not as expensive as mainframes.
• The first microcomputer was invented by Bill
Pentz.
• It can support working of hundreds of users
simultaneously.
• Their processing speed is in the range of 10 to 30
MIPS.

12. 1A-12
Computers For Organizations
• Supercomputers
– The most powerful
computers made
– A supercomputer is a
computer with a high
level of performance as
compared to a general-
purpose computer.
– Handle large and
complex calculations
– Process trillions of
operations per second
– Found in research
organizations

13. 1A-13
Computers In Society
• More impact than any other invention
– Changed work and freedom activities
– Used by all demographic groups
• Computers are important because:
– Provide information to users
– Information is critical to our society
– Managing information is difficult

14. 1A-14
Computers In Society
• Computers at home
– Many homes have multiple computers
– Most homes have Internet
– Computers are used for
• Business
• Entertainment
• Communication
• Education

15. 1A-15
Computers In Society
• Computers in education
– Computer literacy required at all levels
• Computers in small business
– Makes businesses more profitable
– Allows owners to manage
• Computers in industry
– Computers are used to design products
– Assembly lines are automated

16. 1A-16
Computers In Society
• Computers in government
– Necessary to track data for population
• Police officers
• Tax calculation and collection
– Eg MTMIS
– Governments were the first computer users

17. 1A-17
Computers In Society
• Computers in health care
– Revolutionized health care
– New treatments possible
– Scheduling of patients has improved
– Delivery of medicine is safer