Transcript Slide 1

William Miller - Instructor
William Miller - Instructor
William Miller - Instructor
Chapter 1
Computers and Digital Basics
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ABACUS
4th Century B.C.
The abacus, a simple counting aid,
may have been invented in Babylonia
(now Iraq) in the fourth century B.C.
This device allows users to make
computations using a system of
sliding beads arranged on a rack.
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BLAISE PASCAL
(1623 - 1662)
In 1642, the French mathematician
and philosopher Blaise Pascal
invented a calculating device that
would come to be called the "Adding
Machine".
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BLAISE PASCAL
(1623 - 1662)
Originally called a "numerical wheel calculator" or
the "Pascaline", Pascal's invention utilized a train of
8 moveable dials or cogs to add sums of up to 8
figures long. As one dial turned 10 notches - or a
complete revolution - it mechanically turned the next
dial.
Pascal's mechanical Adding Machine automated the
process of calculation. Although slow by modern
standards, this machine did provide a fair degree of
accuracy and speed.
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CHARLES BABBAGE
(1791 - 1871)
Born in 1791, Charles Babbage was an English
mathematician and professor.
In 1822, he persuaded the British government to
finance his design to build a machine that would
calculate tables for logarithms.
With Charles Babbage's creation of the "Analytical
Engine", (1833) computers took the form of a
general purpose machine.
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HOWARD AIKEN
(1900 - 1973)
Aiken thought he could create a modern and
functioning model of Babbage's Analytical Engine.
He succeeded in securing a grant of 1 million
dollars for his proposed Automatic Sequence
Calculator; the Mark I for short. From IBM.
In 1944, the Mark I was "switched" on. Aiken's
colossal machine spanned 51 feet in length and 8
feet in height. 500 meters of wiring were required
to connect each component.
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HOWARD AIKEN
(1900 - 1973)
The Mark I did transform Babbage's
dream into reality and did succeed in
putting IBM's name on the forefront of
the burgeoning computer industry.
From 1944 on, modern computers
would forever be associated with digital
intelligence.
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ENIAC
1946
Electronic Numerical Integrator And Computer
Under the leadership of J. Presper Eckert (1919 1995) and John W. Mauchly (1907 - 1980) the team
produced a machine that computed at speeds 1,000
times faster than the Mark I was capable of only 2
years earlier.
Using 18,00-19,000 vacuum tubes, 70,000 resistors
and 5 million soldered joints this massive instrument
required the output of a small power station to
operate it.
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ENIAC
1946
It could do nuclear physics calculations (in two
hours) which it would have taken 100 engineers a
year to do by hand.
The system's program could be changed by
rewiring a panel.
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ENIAC
1946
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TRANSISTOR
1948
In the laboratories of Bell Telephone, John
Bardeen, Walter Brattain and William Shockley
discovered the "transfer resistor"; later labelled
the transistor.
Advantages:
increased reliability
1/13 size of vacuum tubes
consumed 1/20 of the electricity of vacuum tubes
were a fraction of the cost
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TRANSISTOR
1948
This tiny device had a huge impact on and extensive
implications for modern computers. In 1956, the
transistor won its creators the Noble Peace Prize for
their invention.
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ALTAIR
1975
The invention of the transistor made computers
smaller, cheaper and more reliable. Therefore, the
stage was set for the entrance of the computer into
the domestic realm. In 1975, the age of personal
computers commenced.
Under the leadership of Ed Roberts the Micro
Instrumentation and Telemetry Company (MITS)
wanted to design a computer 'kit' for the home
hobbyist.
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ALTAIR
1975
Based on the Intel 8080 processor, capable of
controlling 64 kilobyes of memory, the MITS Altair
- as the invention was later called - was debuted
on the cover of the January edition of Popular
Electronics magazine.
Presenting the Altair as an unassembled kit kept
costs to a minimum. Therefore, the company was
able to offer this model for only $395. Supply
could not keep up with demand.
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ALTAIR
1975
ALTAIR FACTS:
No Keyboard
No Video Display
No Storage Device
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IBM (PC)
1981
On August 12, 1981 IBM announced its own
personal computer.
Using the 16 bit Intel 8088 microprocessor, allowed
for increased speed and huge amounts of memory.
Unlike the Altair that was sold as unassembled
computer kits, IBM sold its "ready-made" machine
through retailers and by qualified salespeople.
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IBM (PC)
1981
To satisfy consumer appetites and to
increase usability, IBM gave prototype
IBM PCs to a number of major software
companies.
For the first time, small companies and
individuals who never would have
imagined owning a "personal"
computer were now opened to the
computer world.
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MACINTOSH
(1984)
IBM's major competitor was a company lead by Steve
Wozniak and Steve Jobs and Ronald Wayne; the Apple
Computer Inc. The "Lisa" was the result of their
competitive thrust. This system differed from its
predecessors in its use of a "mouse" - then a quite
foreign computer instrument - in lieu of manually
typing commands. However, the outrageous price of
the Lisa kept it out of reach for many computer buyers.
*Ronald Wayne gave up his share of the new company for a total of $2,300.
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MACINTOSH
(1984)
Apple's brainchild was the Macintosh. Like the
Lisa, the Macintosh too would make use of a
graphical user interface.
Introduced in January 1984 it was an immediate
success.
The GUI (Graphical User Interface) made the
system easy to use.
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MACINTOSH
(1984)
The Apple Macintosh debuts in 1984. It
features a simple, graphical interface,
uses the 8-MHz, 32-bit Motorola 68000
CPU, and has a built-in 9-inch B/W
screen.
1 The Digital Revolution
Digital revolution - an ongoing process of social, political, and
economic change brought about by digital technology, such
as computers and the Internet
Revolves around a constellation of technologies, including
digital electronics, computers, communications networks, the
Web, and digitization
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1 The Digital Revolution
 Digital electronics use electronic circuits to represent data
 Digital electronic devices include computers, portable media
players such as iPods, digital cameras and camcorders, cell
phones, radios and televisions, GPSs, DVD and CD players,
e-book readers, digital voice recorders, and handheld
gaming consoles
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1 The Digital Revolution
Computer Ownership in the USA
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1 The Digital Revolution
What Caused the sudden upswing in computer ownership?
 The second phase of the digital revolution materialized when
the Internet was opened to public use
– E-mail
– Bulletin boards
– Chat groups
• Blogs
– Online social
networks
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1 The Digital Revolution
Some Terms:
A computer network is a group of computers linked by wired
or wireless technology to share data and resources
The Web is a collection of linked documents, graphics, and
sounds that can be accessed over the Internet
Cyberspace is a term that refers to entities that exist largely
within computer networks
Digitization is the process of converting text, numbers, sound,
photos, and video into data that can be processed by digital
devices
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1 Convergence
Technological convergence -process by
which several technologies with distinct
functionalities evolve to form a single
product
Convergence tends to offer enhanced
functionality and convenience
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1 Digital Society
 Digital technologies and communications networks make it
easy to cross cultural and geographic boundaries
 Anonymous Internet sites, such as Freenet, and anonymizer
tools that cloak a person’s identity, even make it possible to
exercise freedom of speech in situations where reprisals
might repress it
 Citizens of free societies have an expectation of privacy
 Intellectual property refers to the ownership of certain types
of information, ideas, or representations
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1 Digital Society
 Digital technology is an important factor in global and
national economies, in addition to affecting the economic
status of individuals
 Globalization - the worldwide economic interdependence of
countries that occurs as cross-border commerce increases
and as money flows more freely among countries
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1 Digital Society
 Individuals are affected by the digital divide, a term that
refers to the gap between people who have access to
technology and those who do not
 Digital technology permeates the very core of modern life
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SECTION
B
Digital Devices
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1 Computer Basics
 A computer is a multipurpose device that accepts input,
processes data, stores data, and produces output, all
according to a series of stored instructions
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1 Computer Basics
 Input - whatever is typed, submitted, or
transmitted to a computer system
 Output the result produced by a computer
 Data - refers to the symbols that represent facts,
objects, and ideas
 Computers manipulate data in many ways, and
this manipulation is called processing
– Central Processing Unit (CPU)
– Microprocessor
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1 Computer Basics
 Memory - area of a computer that temporarily holds data
waiting to be processed, stored, or output
 Storage - area where data can be left on a permanent basis
when it is not immediately needed for processing
 File - named collection of data that exists on a storage
medium
 Computer program - series of instructions that tells a
computer how to carry out processing tasks.
– Software
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1 Computer Basics
 Stored program - a series of instructions for a computing
task can be loaded into a computer’s memory
– Allows you to switch between tasks
– Distinguishes a computer from other simpler devices
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1 Computer Basics
 Application software - set of computer programs that helps
a person carry out a task
 System software - helps the computer system monitor itself
in order to function efficiently
– Operating system (OS)
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Personal Computers, Servers,
Mainframes, and Supercomputers
 A personal computer is a microprocessor-based computing
device designed to meet the computing needs of an
individual
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Personal Computers, Servers,
Mainframes, and Supercomputers
 The term workstation has two meanings:
– An ordinary personal computer that is connected to a
network
– A powerful desktop computer used for high-performance
tasks
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Personal Computers, Servers,
Mainframes, and Supercomputers
 Videogame console: not generally referred to as
personal computers because of their history as
dedicated game devices.
– Nintendo’s Wii
– Sony’s PlayStation
– Microsoft’s Xbox
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Personal Computers, Servers,
Mainframes, and Supercomputers
 Server - serves other computers on a network (such as the
Internet or a home network) by supplying them with data.
 Mainframe computer (or simply a mainframe) is a large and
expensive computer capable of simultaneously processing
data for hundreds or thousands of users
 Supercomputer - at the time of construction, one of the
fastest computers in the world
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1 PDAs, Smart Phones, and
Portable Media Players
 PDA (personal digital assistant) - pocket-sized digital
appointment book with a small qwerty keyboard or a touchsensitive screen, designed to run on batteries and be used
while holding it.
– Palm Pilot
 Handheld computer - essentially a PDA enhanced with
features such as removable storage, e-mail, Web access,
voice communications, built-in camera, and GPS
– Apple iPhone, Palm Treo, RIM Blackberry
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1 PDAs, Smart Phones, and
Portable Media Players
 Smart phone - in addition to voice communication, includes
features such as full qwerty keypad, text messaging, e-mail,
Web access, removable storage, camera, FM radio, digital
music player, and software options for games, financial
management, personal organizer, GPS, and maps
 Portable media players - device that their main strength is
playing music, showing videos, and storing photos such as
iPods.
Chapter
______ 1: ________
Computers
___
and
______
Digital_____
Basics
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1 Microcontrollers
 Microcontroller - a special-purpose microprocessor that is
built into the machine it controls
 Microcontrollers - can be embedded in all sorts of everyday
devices
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SECTION
C
Digital Data Representation
 Data Representation Basics
 Representing Numbers, Text, and Pictures
 Quantifying Bits and Bytes
 Circuits and Chips
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1 Data Representation
 Data representation refers to the form in which data is
stored, processed, and transmitted
 Digital devices work with distinct and separate data
 Analog devices work with continuous data
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1 Representing Numbers, Text,
and Pictures
 Numeric data
– Binary number system
 Character data – Composed of
letters, symbols and numerals that
are not involved in arithmetic
operations. Digital devices employ
several types of coeds that represent
character data:
– ASCII, Extended ASCII, EBCDIC,
and Unicode
 Digitizing - process of converting
analog data into digital format
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1 Data Representation
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1 Quantifying Bits and Bytes
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1 Circuits and Chips
 Integrated circuit (computer chip) - super-thin slice of
semiconducting material packed with microscopic circuit
elements
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1 Circuits and Chips
 System board – The
“main” circuit board of a
digital device. This is
where most of the
electronics are typically.
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SECTION
D
Digital Processing
 Programs and Instruction Sets
 Processor Logic
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1 Programs and Instruction Sets
 Computer programmers - create programs that control
digital devices. These programs are usually written in a highlevel programming language
 Source code - The human-readable version of a program
created in a high-level language by a programmer.
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1 Programs and Instruction Sets
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1 Programs and Instruction Sets
 Instruction set - a collection of preprogrammed activities a
microprocessor is hardwired to perform
 Each instruction has a corresponding sequence of 0s and 1s
 The end product is called machine code
– 1s and 0s
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1 Programs and Instruction Sets
 Op code (short for operation code) - command word for an
operation such as add, compare, or jump
 Operand - specifies the data, or the address of the data, for
the operation
 In the following instruction, the op code means add and the
operand is 1, so the instruction means Add 1
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1 Programs and Instruction Sets
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1 Processor Logic
 ALU (arithmetic logic unit) - the part of the microprocessor
that performs arithmetic operations
 Registers - what the ALU uses to hold the data that is being
processed
 Control unit - The microprocessor’s control unit fetches
each instruction, just as you get each ingredient out of a
cupboard or the refrigerator
 Instruction cycle - refers to the process in which a
computer executes a single instruction
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1 Processor Logic
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1 Processor Logic
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1
SECTION
E
Password Security
 Authentication Protocols
 Password Hacks
 Secure Passwords
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1 Authentication Protocols
 Authentication Protocol - method that confirms a person’s
identity using something the person knows, something the
person possesses, or something the person is
– A person can also be identified by biometrics, such as a
fingerprint, facial features (photo), or retinal pattern
– A user ID is a series of characters—letters and possibly
numbers or special symbols—that becomes a person’s
unique identifier
– A password is a series of characters that verifies a user
ID and guarantees that you are the person you claim to
be
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1 Authentication Protocols
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1 Password Hacks
 Identity theft - When someone gains unauthorized access
to your personal data and uses it illegally
 Hackers employ a wide range of ways to steal passwords
 Dictionary attack - helps hackers guess your password by
stepping through a dictionary containing thousands of the
most commonly used passwords
 Brute force attack - uses password-cracking software, but
its range is much more extensive than the dictionary attack
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1 Password Hacks
 Sniffing - If hackers can’t guess a password, they can use
another technique called sniffing, which intercepts
information sent out over computer networks
 Phishing - attempting to acquire sensitive information such
as usernames, passwords and credit card details by
masquerading as a trustworthy entity in an electronic
communication.
 Keylogger - software that secretly records a user’s
keystrokes and sends the information to a hacker
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1 Password Security
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1 Password Security
 Strive to select a unique user ID that you can use for more
than one site
 Maintain two or three tiers of passwords
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1 Password Security
 Password manager - stores user IDs with their
corresponding passwords and automatically fills in login
forms
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Chapter 1 Complete
Computers and Digital Basics