1. TK 2123 COMPUTER ORGANISATION & ARCHITECTURE
Lecture 1: An Overview of Computer System (1)

2. Course Information Text books: Class: Course website:
Irv Englander, (2003). The Architecture Of Computer Hardware And System Software, 3/E, John Wiley & Sons.
Andrew S. Tanenbaum, (2006). Structured Computer Organization, 5/E, Prentice Hall.
William Stallings, (2006). Computer Organization and Architecture: Designing for Performance, 7/E, Prentice Hall.
Class:
Monday 6:30pm-09:30pm BS 2-1
Course website:
Prepared by: Dr Masri Ayob - TK2123

3. Assessment Assignments : 15% Quiz : 25% Mid Semester Examination : 20%
Final Examination : 40%
Warnings:
Copying assignment/quiz/exam is prohibited.
Delay of submission influences on marks.
Prepared by: Dr Masri Ayob - TK2123

4. Contents This lecture will address:
The ways in which a knowledge of computer architecture enhances our abilities as computer users and professionals.
The input-output-process model of computing.
The basic components of a computer system.
Prepared by: Dr Masri Ayob - TK2123

5. Architecture & Organization
Architecture is those attributes visible to the programmer
Instruction set, number of bits used for data representation, I/O mechanisms, addressing techniques.
e.g. Is there a multiply instruction?
Organization is how features are implemented
Control signals, interfaces, memory technology.
e.g. Is there a hardware multiply unit or is it done by repeated addition?
Prepared by: Dr Masri Ayob - TK2123

6. Introduction Typical elements in computer-based information system:
The data element:
fundamental representation of facts and observations.
Data is processed by a computer system to provide the information that is the very reason for the computer’s existence.
As you will see, data can take on a number of different forms.
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7. Introduction The hardware element:
Computer hardware processes the data by:
Executing instructions.
storing data
and moving data and information between the various input and output devices that make the system and the information accessible to the users.
Prepared by: Dr Masri Ayob - TK2123

8. Introduction The software element: The communication element:
Software consists of the system and application programs that define the instructions that are executed by the hardware.
The communication element:
Modern computer information systems depend on the ability to share processing operations and data among different computers and users, located both locally and remotely. Data communication provides this capability.
Prepared by: Dr Masri Ayob - TK2123

9. Introduction
The combination of hardware, software, communication, and data make up the architecture of a computer system.
The architecture of computer systems is remarkably similar whether the system is a PC, a large mainframe etc.
Prepared by: Dr Masri Ayob - TK2123

10. Introduction
Even more remarkably, the basic architecture of computer systems has changed surprisingly little over the last fifty-five years.
The latest IBM mainframe computer executes essentially the same instruction set as the mainframe computer of 1965.
The basic communication techniques used in today’s systems were developed in the 1970s.
Prepared by: Dr Masri Ayob - TK2123

11. Introduction
As new as it might seem, the Internet celebrated its thirtieth anniversary in 2000.
All of this is surprising considering the growth of computing, the rapid change of technology, and the increased performance, functionality, and ease of use of today’s systems.
This makes the study of computer architecture extremely valuable as a foundation upon which to understand new developments in computing as they occur.
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12. Introduction All Intel x86 family share the same basic architecture
The IBM System/370 family share the same basic architecture
This gives code compatibility
At least backwards
Organization differs between different versions
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13. Structure & Function
Structure is the way in which components relate to each other
Function is the operation of individual components as part of the structure
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14. Function All computer functions are: Data processing Data storage
Data movement
Control
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15. Functional View
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16. Operations: Data movement
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17. Operations: Storage
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18. Operation: Processing from/to storage
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19. Operation : Processing from storage to I/O
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20. Introduction
What do the insides of a computer “look like” and why do we care?
As users, we do not have to know the answer to this question, any more than we have to understand the workings of a car engine in order to drive the car.
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21. Introduction
We can run standard software packages without understanding exactly how they work.
We can program a computer in a high-level language without understanding how the machine executes the individual instructions.
We can create Web pages without understanding how the Web browser gets its pages from a Web server or how the Web server creates those pages.
We can purchase a computer system from a salesperson without understanding the specifications of the system.
Etc……
Prepared by: Dr Masri Ayob - TK2123

22. Introduction And yet, there is something missing.
Perhaps the package doesn’t do exactly what we want, and we don’t understand the machine well enough to risk fooling around with the package’s options.
Perhaps if we understood the system we might have written the program to be faster and more efficient.
Perhaps we could create Web pages that load faster and work better.
Perhaps the salesperson did not sell us the optimum system for our job.
Etc……
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23. Introduction
The jargon of computers has become a part of the English language.
You can open any daily newspaper and find references to “1GB DDRAM” or “XGA TFT display” or “512K level 2 cache” or “56K V.90 modem” in articles and advertisements. (In a way, it’s scary!).
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24. Figure 1.1 A typical computer ad
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25. Introduction But how good a system is this?
Are these features important to the user?
Is this the right combination of features that you need in your computer to have the computer perform the work that you wish to get done?
Is a 2.7 GHz Pentium 4 the best choice of a CPU?
Perhaps we are paying too much for the performance that we need.
Or maybe we need more.
What does the presence of a Firewire port imply in the context of a long-term investment of computers for your organisation?
Is DVD-RAM the most useful format for your work?
Etc……
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26. Introduction
Understanding the computer system’s operations has an immediate benefit: it will allow you to use the machine more effectively.
As a user, you will
be aware of the capabilities, strengths, and limitations of the computer system.
have a better understanding of the commands that you use.
understand what is taking place during the operation of the programs that you use.
understand more clearly what an operating system is, and how to use it effectively and to your advantage.
know when it is preferable to do a job manually, and when the computer should be used.
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27. Introduction As a programmer, it will allow you to
write better programs.
use the characteristics of the machine to make your programs operate more effectively.
For example, choosing the appropriate data type for a variable can result in significantly faster performance.
Soon you will know why this is so, and how to make the appropriate choices.
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28. Introduction As a system analyst, you:
will be expected to specify computer systems for purchase, for yourself and for your organization.
would like to purchase the computer that best meets the needs of the application.
must be able to read and understand the technical specifications in order to compare different alternatives and to match the system to the users’ needs.
should be able to assist management in making intelligent decisions about system strategy.
should able to differentiate between simple technological obsolescence that does not affect your work significantly and major advances that suggest a real need to replace older equipment.
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29. Introduction
As a system administrator or manager, your job is to maximize the availability and efficiency of your systems. You:
will need to understand the reports generated by your systems and be able to use the information in those reports to make changes in the systems that will optimize system performance.
will need to know when additional resources are required, and be able to specify appropriate choices.
will need to specify and configure operating system parameters, set up file systems, manage system and user PC upgrades in a fast-changing environment, provide and assure the robustness of system security, and perform many other system management tasks.
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30. Introduction
A deep understanding of the basic concepts is fundamental to long-term survival and growth in the field of information technology and IT management.
This type of understanding is at the very foundation of being a competent and successful system analyst, system administrator, or programmer.
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31. The User’s Point of View
The purpose of the computer, obviously, is to perform some useful work, whether that work be:
word processing
retrieval and manipulation of data
simple bookkeeping
solving a difficult mathematical problem
Web browsing
or the graphical display and internal calculation associated with a video game or desktop presentation program.
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32. The User’s Point of View
For example, a simple online credit card purchasing system:
When a customer makes a purchase
the clerk keys or scans the transaction into a terminal that is used as input to the department store computer.
The computer communicates with a bank computer that checks the customer’s credit and okays the transaction.
The computer prints a receipt at the terminal for the customer to sign and records the transaction in the customer’s account.
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33. Figure 1.2 A simplified credit card transaction
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34. The User’s Point of View
For this example,
The primary processing operations that take place include searching for data, merging of data, and simple calculation.
On this system, input is provided via terminal keyboard. Output occurs on the screen and on a printer. Hard disks provide long-term storage.
Prepared by: Dr Masri Ayob - TK2123

35. The User’s Point of View
A seemingly very different operation occurs when you sit at your personal computer working with a word processor.
But is it really that different?
The text file is probably stored on either a removable disk or a hard disk.
The word processor program itself is also stored on disk.
The text file being processed is initially loaded into the main memory of the computer as data, just as the customer’s credit file was in the previous example.
Word processors also perform comparisons and make decisions, just as the credit card program does.
Prepared by: Dr Masri Ayob - TK2123

36. The Input-Process-Output Model
The critical idea here is that regardless of the type of work to be performed, the work of a computer can be characterized by an input-process-output model (IPO); that is a program:
receives input from a disk file, mouse, keyboard, or some other input device;
performs some processing on the input;
and produces output to a disk file, a printer, a video screen, or some other output device.
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37. Figure 1.3 A computer process
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38. Internet Resources - Web site for book
Student Companion Site (Englander)
Little Man Simulator
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39. Internet Resources - Web site for book
links to sites of interest
links to sites for courses that use the book
errata list for book
information on other books by W. Stallings
Math
How-to
Research resources
Misc
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40. Internet Resources - Web sites to look for
WWW Computer Architecture Home Page
CPU Info Center
Processor Emporium
ACM Special Interest Group on Computer Architecture
IEEE Technical Committee on Computer Architecture
Intel Technology Journal
Manufacturer’s sites
Intel, IBM, etc.
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41. Internet Resources - Usenet News Groups
comp.arch
comp.arch.arithmetic
comp.arch.storage
comp.parallel
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42. Thank you Q&A
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