1. ITEC 1000 Introduction to Information Technologies
Fall 2014

2. An Information Technology Approach
Textbook
The Architecture of
Computer Hardware
and
Systems Software
An Information Technology Approach
5th Edition, 2000
Irv Englander
John Wiley & Sons

3. Time 11:30 PM – 2:30 PM
Room TEL 0006
Mid-term Exam TBA
Final Exam TBA

4. Scoring Assignments 10 points (2) Mid-term exam 40 points
Final exam points

5. Assignments Policy Due dates To be specified
Late Assignments Late assignments will face a 15% penalty for each day after due day. Hence, one day later means 85% is your maximum, 2 days means 70% is your maximum and so on. Saturday and Sunday count also.
Assignments are optional. If you decide not to do them, the weight of the first one will be transferred to the midterm and the second one to the final exam.

6. Directions email cysneiro@yorku.ca office TEL Building 3053
TA: TBA

7. 1. What is a Computer?

8. Modern Computer Development
1937: Mark I is built (Aiken, Harvard University, IBM).
First electronic computer using relays
1939: Atanasoff-Berry Computer (ABC) is built
First fully electronic digital computer; used vacuum tubes
: ENIAC (Mauchly, Eckert, University of Pennsylvania).
First general purpose digital computer
1945: Von Neumann architecture proposed
Still the standard for present day computers
1947: Creation of the transistor
(Bardeen, Shockley, Brattain, Bell Labs)
1951-2: EDVAC and IAS

9. … The ENIAC

10. Vacuum tubes

11. History of computing ENIAC Generations
$3,000,000 cost; vacuum tubes; square foot; 30 tons
Generations
Vacuum tubes – Basic idea Presence or absence of energy
Transistors
Integrated circuits, OS
Ultra Large Scale Integrations
Future

12. Computer System Components
Hardware
Processes data by executing instructions
Provides input and output
Control input, output, and storage components
Software
Applications and system software
Instructions tell hardware exactly what tasks to perform and in what order
Data
Fundamental representation of facts and observations
Communications
Sharing data and processing among different systems

13. Copyright 2013 John Wiley & Sons, Inc.
Computer Systems
All computer systems, no matter how complex, consists of the following:
At least one CPU
Memory to hold programs and data
I/O devices
Long-term storage
Copyright 2013 John Wiley & Sons, Inc.

14. A typical computer system

15. Computing Devices – Old and New
“The Box”
CD-ROM Drive
CRT Display
Floppy
Disk
Drive
Keyboard
Mouse

16. Computing Devices – Old and New

17. Operating System Development
1963: Master Control Program (MCP) by Burroughs
Included many modern OS features
1964: OS/360 by IBM
Included batch processing of programs
1962: MIT Project MAC created a time-sharing OS called CTSS
Shortly afterwards, MIT, Bell Labs, and GE developed Multics (Multiplexed Information and Computing Services)
Copyright 2013 John Wiley & Sons, Inc.

18. System Software History
Early computers had no operating systems and were single user systems
Programs were entered using switches for each bit or by plugging wires into a panel
: First operating system was built by General Motors Research Laboratories for their IBM 701 computer
Other early systems
FORTRAN Monitor System (FMS)
IBSYS
Share Operating System (SOS)

19. UNIX
After Bell Labs withdrew from the Multics project, Ken Thompson developed a personal operating system called UNIX using assembly language
Dennis Ritchie developed the programming language C which was used to rewrite much of UNIX in a high-level language
UNIX introduced
A hierarchical file system
The shell concept
Document production and formatting
Tools for networked and distributed processing

20. Graphical User Interfaces
1960s: Doug Englebart (Stanford Research Institute)
Invented windows and a mouse interface
1970s: Xerox PARC
Creates a practical windowing system for the Dynabook project
1980s: Steve Jobs (Apple)
Developed the Apple Lisa and MacIntosh

21. IBM PC 1982: Stand-alone, single user computer
PC-DOS, MS-DOS (disk operating system)
Later versions of DOS added
Hierarchical directory file storage
File redirection
Better memory management
Windowing systems
Windows 2.0, Windows 3.1, Windows 95
Windows NT, Windows XP, Windows Vista
Windows 7 and 8

22. Communications
1960s and 1970s: users communicated on multiterminal computer systems using talk and facilities
1971: Ray Tomlinson creates the standard standard
Modems permitted users to login to office systems, electronic bulletin board systems, Compuserve, AOL, and Prodigy
1969: ARPANET begun
1985: First TCP/IP wide area network
1991: Tim Berners Lee develops the concepts that become the World Wide Web
1993: Max Andreessen develops Mosaic, the first graphical browser

23. Copyright 2013 John Wiley & Sons, Inc.
What is a system?
What do the following systems have in common?
Plumbing system
Solar system
Home network system
Inventory control system
Copyright 2013 John Wiley & Sons, Inc.

24. Copyright 2013 John Wiley & Sons, Inc.
Plumbing System
Copyright 2013 John Wiley & Sons, Inc.

25. Copyright 2013 John Wiley & Sons, Inc.
Solar System
Copyright 2013 John Wiley & Sons, Inc.

26. Copyright 2013 John Wiley & Sons, Inc.
Home Network System
Copyright 2013 John Wiley & Sons, Inc.

27. Inventory Control System
Copyright 2013 John Wiley & Sons, Inc.

28. Copyright 2013 John Wiley & Sons, Inc.
Definition of a System
“A system is a collection of components linked together and organized in such a way as to be recognizable as a single unit.”
Linked components of a system also define a boundary for the system
The environment is anything outside of the system
Copyright 2013 John Wiley & Sons, Inc.

29. General Representation of a System
Copyright 2013 John Wiley & Sons, Inc.

30. Copyright 2013 John Wiley & Sons, Inc.
System Decomposition
Components
May be irreducible or
May be subsystems
Decomposition
The division of a system into its components and linkages
Hierarchical
Copyright 2013 John Wiley & Sons, Inc.

31. Copyright 2013 John Wiley & Sons, Inc.
System Architecture
“The fundamental properties, and the patterns of relationships, connections, constraints, and linkages among the components and between the system and its environment are known collectively as the architecture of the system”
Copyright 2013 John Wiley & Sons, Inc.

32. Why Computers?

33. Autonomous Cab

34. Disney’s New ‘MyMagic’ Wristbands to Turn Big Data Into Big Profits

35. Why Study Computer System Architecture?
User
Understand system capabilities, strengths, and limitations
Make better informed decisions
Improve communications with information technology professionals
Programmer
Create efficient application software for specific processing needs
Systems Architect or Systems Analyst
Specify computer systems and architecture to meet application requirements
Make intelligent decisions about system strategy

36. Web Browser Application Use

37. Input-Process-Output Model (IPO)
Input: keyboard, mouse, scanner
Processing: CPU executes the computer program
Output: monitor, printer, fax machine
Storage: hard drive, optical media, diskettes, magnetic tape

38. Simplified IT Computer System Layout

39. Bits, data and operations
Computer operation = Data processing
Read / write
Arithmetic operations
Comparisons / evaluations of expressions

40. Number systems Importance Basics
Humans use them to count
Computers use them to represent data
Basics
Base: number of different digits used in the number system
Weight / position: rightmost position is that of B0
Positional: Value depends on position:
e.g: Decimal system:
54 = 5 x x 1

41. DEFINITION
The BASE of a number system is how many digits are used in that system.
Base 2: 0, 1
Base 5: 0, 1, 2, 3, 4
Base 8: 0, 1, 2, 3, 4, 5, 6, 7
Base 10: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Base 16: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F KC

42. Most common ones Binary system: based on 1s and 0s (base 2).
Bit = Binary Digit
Decimal system: based on 10 digits including 0 (base 10)
Hexadecimal system: based on 16 digits including 0 (base 16)

43. Counting in different bases1 2 10 3 11 4
100 5
101 6
110 7
111 8
1000 9
1001
1010 A
1011 B 12
1100 C 13
1101 D 14
1110 E 15
1111 F 16
10000

44. Base conversions…. Possible conversions:
From decimal to binary or the opposite
From decimal to hexadecimal or the opposite
From binary to hexadecimal or the opposite
From octal to hexadecimal or the opposite
Quick example: 2510 = = 318 =1916

45. Before conversions Review the positional decimal system
The number 125 means:
1 group of 100 (100 = 102)
2 groups of 10 (10 = 101)
5 groups of 1 (1 = 100) KC

46. Place values
In our usual positional number system, the meaning of a digit depends on where it is located in the number
Example:
3 groups of 1000
7 groups of 100
3 groups of 10
2 groups of 1
/KC

47. Base and Weight
Weight
12510 => 5 x 100 = x 101 = x 102 =
Base

48. …any base to decimal The steps
From right to left, the powers of the base are B0, B1, B2, .., Bn
Multiply each digit by the corresponding power of the base
Add up the result
Decimal values of numbers in base B:
= 5*1 + 6*10 +, 1*100 with 100 = 102, 10 = 101 and 1 = 100
=165
= 1*20 + 0*21 + 1*22
= 5
1A = 10* *161
= 26
Got it? What is the decimal value of ABC16 ?

49. ABC = C*160 + B*161 + A*162
= 12* * *162
= 12*1 + 11* *256 = =

50. Other conversions Decimal to binary
Divide by 2 repeatedly and keep track of the remainder
1st remainder is digit corresponding to 20 (LSB, least-significant bit)
2nd remainder is digit corresponding to 21
3rd remainder is digit corresponding to 22, etc.

51. Example
12510 = ?2
12510 =

52. Decimal to hexadecimal
Divide by 16 repeatedly and keep track of the remainder
Then same as above, 1st remainder = LSB and last one = MSB

53. Example
= ?16
77 2 16
= D
0 4
= 4D216

54. Binary to hexadecimal Group bits in fours, starting on right
Convert each group to an hexadecimal digit

55. Example
= ?16
2 B B
= 2BB16

56. Hexadecimal to binary
Convert each hexadecimal digit to a 4-bit equivalent binary representation

57. Example
10AF16 = ?2
A F
10AF16 =

58. Exercise – Convert ... Decimal Binary Octal Hexa- decimal 33 1110101
703
1AF
Don’t use a calculator!

59. Why Binary? Early computer design was decimal
Mark I and ENIAC
John von Neumann proposed binary data processing (1945)
Simplified computer design
Used for both instructions and data
Natural relationship between on/off switches and calculations using Boolean logic On
Off
True
False
Yes No 1

60. Binary system in computing
Common powers of 2
210 = K = 1024
220 = M =1024 K
230 = G = 1024 M
Measuring the capacity memory in computing
Size of data: bit versus byte
How many bytes can you store on a 1.44 Megabyte floppy?
Information in computers is stored as 0’s and 1’s
How come? Keys on keyboard are not just 0s and 1s! Monitors and printers do not show just 0s and 1s
Answer: Next slide
26  210 = 216 = 65,536
or…
26  210 = 64  210 = 64k

61. Addition
Base 10
8 + 1 = 9
8 + 2 = ?
Ooops. Base 10 goes from 0 to 9 !!
So =9
9 + 1 = Exceed the base. Goes back to 0 an carry 1 10

62. Addition
Base 10
8 + 3 ?
8 + 1 = 9
9 +1 = ?
Ooops. Base 10 goes from 0 to 9 !!
So =9
9 + 1 = Exceed the base. Goes back to 0 an carry 1 10
Only added 2 units up to now still have to add one more unit
10 + 1
---- 11

63. Addition Base 10 The same applies to all Bases
? – Goes Digit by Digit from right to Left
9 +1 = ?
Ooops. Base 10 goes from 0 to 9 !!
9 + 1 = Exceed the base. Goes back to 0 an carry 1
Next Digit is 1 + the carry = 2 hence 20
The same applies to all Bases

64. Binary Addition (1 of 2) Two 1-bit values A B A + B 1 101 10
“two”
Hint: Learn This Table !!
Text : pp 37-40

65. Binary Addition (2 of 2) Two n-bit values Add individual bits
Propagate carries
E.g., 1 1

66. Octal Addition
432 +
233
655
1 1
536 +
425
1163

67. Hexadecimal Addition
43A +
7B3
BED
5B6 +
D2F
12E5

68. Translation & reverse translation
Translation to binary during input
Reverse translation during display
Problem: A same pattern of bits can represent a character, a color, a sound, etc.
Solution: Data formats (i.e. detailed description of the data and their representation) help interpret the reverse translation