Review of computer systems. Evolution of computer systems. Architecture and components of computer systems. Use of computer systems. Data representation in computer systems.

1. Introduction to Information Systems
COURSE TEXTBOOK
June J. Parsons and Dan Oja, New
Perspectives on Computer Concepts 11th
Edition—Comprehensive, Thomson
Course Technology, a division of Thomson
Learning, Inc Cambridge, MA,
COPYRIGHT © 2008; ISBN-10: 1-4239-
2518-1, ISBN-13: 978-1-4239-2518-7.
Introduction to Computer Systems
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2. Introduction to Information Systems
ICT Hardware/Software
Requirements
• Microsoft Windows-based machine
• To see movie files Windows compatible sound card and
speakers (or headphones) are needed.
• Visual Basic 6.0 or higher is required.
• Microsoft Access 2000 or higher is required.
• WinZip application is required.
Introduction to Computer Systems
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3. Introduction to Information Systems
Computer Systems
Lecture 2 (part 1)
2.1 Overview of Computer Systems
2.2 Evolution of Computer Systems
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4. Introduction to Information Systems
2.1.1 Components of a
Computer System
• Hardware System
• Software System—Operating System
Software and Application Software
• Network System
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5. Introduction to Information Systems
Subsystems of a
Computer
Software System
•Operating System (Unix, Mac OS, Microsoft
Windows)
•Web browser (Firefox, Internet Explorer)
•Office productivity applications (Microsoft
Office, Star Office)
Hardware System
•Keyboard
•Monitor
•System unit
Network System
•Internet services (email)
•Network connections (modems, network cards)
Internet
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6. Introduction to Information Systems
Hardware System
Speakers
Printer
Mouse
Keyboard
Monitor
System unit
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7. Introduction to Information Systems
Components inside the System
Unit
B. Power supply
E. Expansion card
C. Microprocessor
(underneath a
cooling fan)
D. Expansion slot
G. IDE cable
F. Chipset
H. Disk drives
A. Motherboard
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8. Introduction to Information Systems
Processor Performance
• Rate at which the instructions are processed
(clock rate)
• Measured in Hertz
• 1 Hertz - one cycle per second
• Processor clock rate measured in MHz

9. Introduction to Information Systems
Processor Performance
(continued)
• Machines are compared based on their clock
speed or number of instructions per second
(ISP).
• This measure depends on both the number of
cycles per second and the mix of instructions
executed.
• Measure of processor performance is
benchmarking.

10. Introduction to Information Systems
Types of Memory
Chipset
(controls data flow)
Microprocessor
(executes instructions)
Storage Devices
(permanently store data
and application programs)
Peripherals
(input/output)
Data Path
Components
Legend
RAM
(instructions to be
executed after computer is
booted)
ROM
(instructions needed to
boot the computer)
CMOS
(Configuration information
used in the boot process)
Main Memory
Boot Memory
Memory

11. Introduction to Information Systems
Types of Memory (continued)
• RAM (random access memory) is a temporary holding
area for both data and instructions. It is also referred to
as main memory.
- Data in RAM is lost when computer is turned off.
- Measured by its memory capacity and latency.
• Capacity is the maximum number of bits or bytes that
can be stored. The capacity of RAM is typically
measured in megabytes (MB). Many computers have
RAM capacity of 128MB or more.
• Latency is the delay between the time when the memory
device receives an address and the time when the first
bit of data is available from the memory device. This
delay is also referred to as access time. Latency is
typically measured in nanoseconds (ns), billionth of a
second (10-9 sec). Latency measures the speed of
RAM.

12. Introduction to Information Systems
DRAM
• DRAM - Dynamic RAM is a common type of
RAM.
– Made of an integrated circuit (IC), composed
of millions of transistors and capacitors.
– Capacitor holds electrons. An empty capacitor
represents a zero, and a non-empty capacitor
represents a one. Each capacitor can register
either a zero or a one for a memory cell,
storing one bit of data.
– The transistor is like a switch that controls
whether the capacitor's state (charged or not
charged, 1 or 0) is to be read or changed.

13. Introduction to Information Systems
DRAM (continued)
– However, a capacitor is like a cup that leaks,
in order to keep its charge, the memory
control needs to be recharged or refreshed
periodically. Therefore, it is called the
dynamic RAM because its state is not
constant.
– Refreshing capacitors also takes time and
slows down memory.

14. Introduction to Information Systems
DRAM (continued)
• SDRAM (Synchronous Dynamic RAM)
– Used in many personal computers
– Fast and relatively inexpensive
– Synchronized to the clock so that data can be
sent to the CPU at each tick of the clock,
increasing the number of instructions the
processor can execute within a given time

15. Introduction to Information Systems
DRAM (continued)
• DDR SDRAM (Double Data Rate SDRAM)
– Transfers twice the amount of data per clock
cycle compared to SDRAM
– Capacity is up to 2 GB

16. Introduction to Information Systems
DRAM (continued)
• RDRAM (Rambus Dynamic RAM)
– Higher bandwidth than SDRAM
– More expensive compared to SDRAM
– Enhances the performance of applications
that access large amounts of data through
memory, i.e. real-time video and video editing

17. Introduction to Information Systems
DRAM (continued)
• SRAM (Static RAM)
– Uses transistors to store data
– Because SRAM does not use capacitors,
reading data from SRAM does not require
recharging the capacitors. Therefore, it is
faster than DRAM.
– Holds fewer bits and costs more compared to
DRAM of the same size
– Used in the cache because it is fast and
cache does not require a large memory
capacity

18. Introduction to Information Systems
RAM Comparisions
Type of RAM Capacity Price
SDRAM @@ $
DDR SDRAM @@@ $
RDRAM @@@ $$
SRAM @ $$$

19. Introduction to Information Systems
What is Software?
• Software is a set of computer instructions
or data.
• Software receives input from the user
and processes this input through the
computer to produce output.
• Software directs how the computer
interacts with the user.
• Software specifies how to process the
user's data
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20. Introduction to Information Systems
Software System
• Two categories: operating system (OS)
software and application software.
• Operating system software, also called
system software, is the master controller for
all activities that take place within a computer
– Examples of OS software:
• Microsoft Windows, Unix, Mac OS
• Application software is a set of one or more
computer programs that helps a person carry
out a task
– Examples of application software:
• Microsoft Word
• Internet Explorer
• Macromedia Dreamweaver
• Adobe Acrobat Reader
Hardware System
Application Software
Operating System Software
Users
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21. Introduction to Information Systems
Network System
• A network provides connections among computers
to enable computers on a network to share data
(e.g. documents), hardware (e.g. printers), and
software resources (e.g. application programs).
• Network users can also send messages to each
other.
• A network must be secured to protect data from
unauthorized usage (e.g. using login name and
password to gain access to a network).
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22. Introduction to Information Systems
Network connection
components:
•Network Interface Card
(NIC)
•Modem
•Phone line or cable
•Internet Service
Provider (ISP)
Internet
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23. Introduction to Information Systems
Evolution of Computers
• Needed calculation devices to keep track of
accounting for commerce
• 1200s—Manual Calculating Devices: the
abacus
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24. Introduction to Information Systems
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25. Introduction to Information Systems
Evolution of Computers (continued)
• 1600s—Mechanical Calculators
– Used wheels, gears, and counters
– To work a mechanical calculator, the operator
enters the numbers for a calculation, and then
pulls a lever or turns a wheel to carry out the
calculation
– Example: the Pascaline invented by Blaise
Pascal. It used some principles of the
abacus, but used wheels to move counters.
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26. Introduction to Information Systems
Evolution of Computers (continued)
• 1800s—Punched Cards
– Used holes following a specific pattern to represent the
instructions given to the machine or stored data
– Different program instructions can be stored on
separate punched cards, which can be fed through the
computing machine repeatedly.
– Once punched, the cards were fed into a card reader
that used an array of metal rods to electronically read
the data from the cards and tabulate the results. This is
called the Hollerith Tabulating Machine
– Hollerith incorporated The Tabulating Machine better
known today as IBM.
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27. Introduction to Information Systems
Evolution of Computers (continued)
• Charles Babbage designed a new general-
purpose calculating device, the Analytical
Engine, which is the ancestor of modern
computers.
– It included the essential components of present-day computers,
which are input, process, storage, and output of data.
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28. Introduction to Information Systems
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29. Introduction to Information Systems
Evolution of Computers (continued)
• 1940s—Vacuum Tubes
– Used to control the flow of electrons. Since vacuum tubes responded faster
than mechanical components, faster computations were possible. But, the
tubes consumed a lot of power and burned out quickly.
– The first computer prototype using vacuum tubes was ENIAC (Electronic
Numerical Integrator and Computer). It was designed to calculate
trajectory tables for the U.S. Army during World War II, but it was not
completed until three months after the war.
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30. Introduction to Information Systems
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31. Introduction to Information Systems
Evolution of Computers (continued)
• 1950s—Transistors
– Smaller, cheaper, more reliable, and consumed
less power than vacuum tubes.
– Could perform 200,000 to 250,000 calculations
per second.
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32. Introduction to Information Systems
Evolution of Computers (continued)
• 1960s—Integrated Circuits
– Thin slice of silicon packed with microscopic
circuit elements such as wire, transistors,
capacitors, and resistors.
– Enabled the equivalent of thousands of
vacuum tubes or transistors to be packed
onto a single miniature chip about the size of
your fingernail
– Reduces the physical size, weight, and power
requirements for devices such as computers
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33. Introduction to Information Systems
Evolution of Computers (continued)
• 1970s to Present—Microprocessor
– Combined components of a computer on a
microchip
– Can be manufactured and then programmed for
various purposes
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34. Introduction to Information Systems
Moore’s Law
• Law can be stated as:
Number of transistors on a microchip
doubles every 18 months.
• Predictions based on Moore’s Law
–Processing power (speed) doubles
every 18 months.
–Storage capacity of RAM increases
exponentially.
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35. Introduction to Information Systems
Applications of Computer
Systems
• In Education
– Multimedia-Facilitated Learning
– Simulation-Based Education
– Intelligent Machine-Based Training
– Interactive Learning
• In Business
– Supply Chain Management
– Project Management
– Customer Relationship Management
– Sales and Marketing Using Electronic Commerce
– Manufacturing Research
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