Introduction to computer science Fall-2018

1. 1.1

2. +
Dr Ramadan Babers
Faculty of Science - Helwan University
Fall – 2018
Introduction
to
Computer
LEC - 1

3. Chapter 1 Outlines
1. Introduction
2. History
3. The Birth of Computers
4. von Neumann Architecture
5. The Modern Era: 1950 to the Present
6. Types of Computers
7. Basic Elements of a Computer System
8. Main Memory
9. Memory Types
10. Input / Output Devices
3

4. +
Introduction
4

5. 1. Introduction
5
A computer or computing machine
is a device that performs mathematical
and logical operations on symbols and other
forms of information at high speed and with
precision.

6. +
History
6

7. 2. History
7
1672: The Pascaline
 Designed and built by
Blaise Pascal
 One of the first
mechanical calculators
 Could do addition and
subtraction The Pascaline: One of the Earliest
Mechanical Calculators

8. 2. History
8
1801: The Jacquard loom
 Developed by Joseph
Jacquard
 Automated loom
 Used punched cards to
create desired pattern
Drawing of the Jacquard Loom

9. 2. History
9
1823: The Difference Engine
 Developed by Charles Babbage
 Did addition, subtraction, multiplication, and
division to 6 significant digits
 Solved polynomial equations and other complex
mathematical problems

10. + The Birth of Computers
10

11. 3. The Birth of Computers
11
The Birth of Computers (1940-1950)
Development of electronic, general-purpose
computers
 Did not begin until after 1940
 Was fueled in large part by needs of World War II
Early computers
 Mark I
 ENIAC
 ABC system
 Colossus
 Z1

12. 3. The Birth of Computers
12
Photograph of the ENIAC Computer

13. 3. The Birth of Computers
13
The Birth of Computers (1940-1950)
Stored program computer model
 Proposed by John Von Neumann in 1946
 Stored binary algorithm in the computer’s memory
along with the data
 Is known as the Von Neumann architecture
 Modern computers remain, fundamentally, Von
Neumann machines
 First stored program computers
• EDVAC
• EDSAC

14. +
von Neumann Architecture
14

15. 4. von Neumann architecture
15
The von Neumann architecture—also known as
the von Neumann model or Princeton architecture—
is a computer architecture based on a 1945 description
by the mathematician and physicist John von
Neumann
https://en.wikipedia.org/wiki/Von_Neumann_architecture

16. + The Modern Era:
1950 to the Present
16

17. 5. The Modern Era: 1950 to the Present
17
Five Generations
(1950-1959)
(1959-1965)
(1965-1975)
(1975-1985)
(1985-?)

18. 5.1 First generation of computing (1950-1959)
18
 Vacuum tubes used to store data and
programs
 Each computer was multiple rooms in
size
 Computers were not very reliable

19. 5.2 Second generation of computing (1959-1965)
19
 Transistors and magnetic cores
replaced vacuum tubes
 Dramatic reduction in size
Computer could fit into a single
room
 Increase in reliability of computers
 Reduced cost of computers
 High-level programming
languages
The programmer occupation
was born

20. 5.3 Third generation of computing (1965-1975)
20
 Integrated circuits rather than individual electronic
components were used
 Further reduction in size and cost of computers
Computers became desk-sized
First minicomputer developed
 Software industry formed

21. 5.4 Fourth generation of computing (1975-1985)
21
 Reduced to the size of a
typewriter
 First microcomputer developed
 Desktop and personal computers
common
 Appearance of
- Computer networks
- Electronic mail
- User-friendly systems
(graphical user interfaces - GUI)
- Embedded systems

22. 5.5 Fifth generation of computing (1985-?)
22
 Massively parallel processors
 Handheld devices and other types of Personal Digital
Assistants (PDAs)
 High-resolution graphics
 Powerful multimedia user interfaces incorporating sound,
voice recognition, touch, photography, video, and television
 Integrated global telecommunications incorporating data,
television, telephone, fax, the Internet, and the World Wide
Web
 Wireless data communications
 Massive storage devices

23. +
Types of Computers
23

24. 6. Types of Computers
24
1- Embedded computers
2- Non-embedded

25. 6.1 Embedded computers
25
 A computer that is an internal component of
another machine.
 Airplanes to television sets contain embedded
computers.
 Used for controlling chemical and mechanical
processes in industry for automation.

26. 6.2 non-embedded
26
 is a device that performs mathematical and logical
operations on symbols and other forms of
information at high speed and with precision.

27. + Basic Elements of a
Computer System
27

28. 7. Basic Elements of a Computer System
28

29. 7. Basic Elements of a Computer System
29
Input devices
include keyboard, mouse,
webcam, or compact disk (CD).
Output devices
may be visual display units,
printers, or plotters.
The Arithmetic and Logic Unit (ALU) and
the control unit make up the Central
Processing Unit (CPU). All calculations
are performed and all comparisons
(decisions) are made in the ALU. Once
data is fed into main memory from input
devices, it is held and transferred as
needed to the arithmetic and logic unit
where processing takes place.

30. +
Main Memory
30

31. 8. Main Memory
31
 The main memory (also called primary storage) has a lot
in common with post office mailboxes. Each box can hold
different items.
 The main memory of a computer also has many small
storage areas. Each one is assigned an address which is
a built-in and unique number that identifies the location.

32. 8. Main Memory
32
 Memory addresses are
expressed in binary form.
 The smallest usable unit of
measure for memory is the
byte .
 Byte is a amount of memory
required to hold one
character, like the letter A or
the numeral 2.

33. 8. Main Memory
33

34. +
Memory Types
34

35. 9. Memory Types
35
Random Access Memory (RAM)
any of the storage locations on a
chip can be randomly selected and
used to directly store and retrieve
data and instructions.
Read Only Memory (ROM)
is not volatile and retains stored
data when the power goes off.
Some of these are programmable
and are thus called Programmable
Read Only Memory (PROM).

36. +
Input / Output Devices
36

37. 10. Input/Output Devices
37
Input/Output devices allow users to communicate with the
computer.
Input
Keyboard
Scanner
Mouse
Touch Screen
Microphone
liquid crystal display (LCD).
Output
Computer Monitors
Printers
Plotter
Speaker