Transcript Computer Concepts A Brief Introduction

Computer Concepts
A Brief Introduction
CAS 133 – Basic Computer
Skills/MS Office XP
Russ Erdman - Instructor
Computer Concepts
“Oh drat these computers! They’re so naughty and so complex,
I could pinch them!”
Computer Concepts
Where can you find computers?

Computers are everywhere
Computer Concepts
What is computer
literacy?

Knowledge and understanding of
computers and their uses.
Computer Concepts
 WHAT IS A
COMPUTER?
A device that follows
instructions, processes
data arithmetically and
logically, produces
output, and stores the
results for future use.
Accepts data (input)
Manipulates data
Produces results
(output)
Stores results
Computer Concepts
What are data and information?
Data
Raw facts,
figures, and
symbols
Information
Data that is
organized,
meaningful,
and useful
Computer Concepts
What are hardware and software?
Hardware
Electronic and
mechanical equipment
Software
Instructions that
tell hardware how
to perform tasks
Computer Concepts
Hardware, Software and the
Computer
Without SOFTWARE the computer HARDWARE is
just a giant PAPER WEIGHT!
Computer Concepts
What are common computer hardware components?
speaker
PC camera
system unit
printer
speaker
monitor
keyboard
modem
scanner
mouse
microphone
digital camera
Computer Concepts
What is an input device?

Hardware used to enter data and instructions.
microphone
PC camera
keyboard
scanner
mouse
digital
camera
Computer Concepts
What is an output device?

Hardware that conveys information to a user.
monitor
printer
speakers
Computer Concepts
What is the system unit?
 Box-like device
containing
electronic
components
connected to
motherboard
CD-RW
drive
Zip®
drive
hard
disk
drive
(inside
case)
CD-ROM
or DVDROM
drive
floppy
disk
drive
Computer Concepts
What are common components inside
the system unit?


Processor
 Memory module

 Expansion cards

• Sound card
• Modem card
• Video card
• Network
interface
card
 Ports and
Connectors
Computer Concepts
What is the motherboard?
Main circuit board
in system unit
 Contains
chips,
integrated circuits,
and transistors
 Also called
the system board

Computer Concepts
What are two main components on the motherboard?
Central Processing Unit
(CPU)
• Also called a processor
• Carries out instructions that tell
computer what to do
Memory (RAM & ROM)
• Temporary holding place for data
and instructions
Computer Concepts
Central Processing Unit
What is a microprocessor?
Single processor chip found
in personal computers
Memory
Computer Concepts
What are two types of system unit
memory?
RAM
ROM
volatile memory
Loses its contents when
thecomputer's
computer'spower
power is
isturned
turnedoff
off
p. 4.16
nonvolatile
memory
Does NOT lose its
contents when
computer’s power is
turned off
Memory
Computer Concepts
What is random access memory (RAM)?
 Memory
chips that can be read from and
written to by processor
 Most RAM is volatile
 The more RAM a computer has, the faster it
operates
memory
module
p. 4.16
Computer Concepts
What is storage?

Holds data, instructions, and information for future use.
Storage
Medium
• Physical material
Click to view
Web Link
then click
Storage Devices
p. 1.7
on which data,
instructions, and
information are
stored
Storage
Device
• Records and retrieves
items to and from
a storage medium
Computer Concepts
What are common storage devices or drives?
CD-RW drive
hard disk
drive
p. 1.7 Fig. 1-3
CD-ROM or
DVD-ROM
drive
ZIP® drive
floppy
disk
drive
Computer Concepts
What is a floppy disk?


Thin, circular,
flexible disk
enclosed in
rigid plastic
A Zip® disk is a
higher capacity
disk
Computer Concepts
What is a hard disk?



p. 7. 10 Fig. 7-12
hard disk
installed in
system unit
High-capacity
storage
Consists of
several
inflexible,
circular platters
that store items
electronically
Components
enclosed in
airtight, sealed
case for
protection
Computer
Concepts
Hard Disks
How does a hard disk work?
1: Circuit board controls
movement of head
activator and small motor
4: Head actuator
positions
read/write head
arms over correct
location on
platters to read or
write data
2: Small motor
spins platters
Step 1
Step 3
p. 7.11 Fig. 7-13
Step 4
3: When software
requests disk
access, read/write
heads determine
location of data
Step 2
Computer Concepts
Compact Discs
What is a compact disc (CD)?



p. 7. 17
Storage
medium
Most PCs
include
some type
of compact
disc
drive
Available in
variety of
formats
Computer Concepts
Compact Discs
A CD-ROM’s layout.
Computer Concepts
Computer Software
What is a computer program?

p. 1.10
A series of instructions that tells the
computer what to do
Computer Concepts
Advantages of a computer
Speed
Reliability
Accuracy
Storage
Communications
Computer Concepts
Advantages of a computer
Speed
Operates at close to the speed of light –
186,000 miles/second!
Consider word processing (typing) over
writing by hand.
Reliability
Hardware seldom fails
When the bank says the computers are
down it may not be true.
Computer Concepts
Advantages of a computer
Accuracy
Software – GIGO (Garbage In Garbage
Out)
Humans make 1 error every 300 characters
typed, computers make 1 error every
3,000,000 characters processed.
Storage
Concept of bits (1s & 0s), bytes (8 bits),
kilobytes (1024 bytes), megabytes (1024
KB), gigabytes (1024 MB), terabytes (1024
GB).
All the works of Shakespeare can fit on
one CD… with much room to spare!
Storage
Computer Concepts
Data Representation

Five basic types of data are
represented in the computer.
 Numeric
 Character
 Visual
 Audio
 Instructional
Computer Concepts
Storage
Data Representation
How do computers represent data?
 Most computers are digital
 Recognize only two discrete states:
on or off
on
off
p. 4.13
1
1
0
1
0
1
0
1
0
0
Storage





Computer Concepts
A digital computer’s circuits are binary.
The circuits can exist in either one of two
electrical states, normally represented by 0
and 1, that is, OFF or ON.
Each 1 or 0 is called a binary digit or bit and
are the basis for measurement of storage.
Each character (letter, number, etc.) equals
one byte.
These bytes can add up, especially when
representing images (graphics).
Computer Concepts
Storage
Consider the math – 1 byte = 1 character,
5 characters per word, 400 words per
page, 200 pages per book.
Floppy Disk = 1,440,000 bytes = 3.6 books
Zip Disk = 100,000,000 bytes = 250 books
CD = 700,000,000 bytes = 1,750 books
DVD = 4,200,000,000 bytes = 10,500 books
Hard Drive (small in lab) = 6,000,000,000
bytes = 15,000 books
Hard Drive (newer) = 100,000,000,000 bytes
= 250,000 books
Computer Concepts
Storage
Representing Symbols and Text
 Each letter and symbol in a text
document must be translated into a
binary number for storage in the
computer.
 Symbols and Text
 Includes characters, punctuation,
symbols representing numbers.
 Each symbol can be assigned a
numeric value
 Two standardized sets of codes for
symbols:
 ASCII (American Standard Code
for Information Interchange)
 EBCDIC (Extended Binary Coded
Decimal Interchange Code)
 Developed by IBM for use on
their mainframe computers.
Storage











Computer Concepts
The ASCII code, or simply ASCII, is used by virtually
all other computers in the United States and Europe
as well. All personal computers use the ASCII code.
A partial listing of the ASCII character set
Ctrl+@(NULL) - 0000000
Ctrl+A - 0000001
Ctrl+B - 0000010
Ctrl+C - 0000011
Ctrl+D - 0000100
Ctrl+E - 0000101
Ctrl+F - 0000110
Ctrl+G(Bell) - 0000111
Space - 0100000
Delete - 1111111











0 - 0110000
1 - 0110001
2 - 0110010
3 - 0110011
4 - 0110100
5 - 0110101
6 - 0110110
7 - 0110111
8 - 0111000
9 - 0111001
: - 0111010











A - 1000001
B - 1000010
C - 1000011
D - 1000100
E - 1000101
F - 1000110
G - 1000111
H - 1001000
I - 1001001
J - 1001010
K - 1001011











a - 1100001
b - 1100010
c - 1100011
d - 1100100
e - 1100101
f - 1100110
g - 1100111
h - 1101000
i - 1101001
j - 1101010
k - 1101011
Storage
Computer Concepts
 A new coding system has recently been developed
called UNICODE.
 Unicode provides a unique number for every
character, no matter what the platform, no matter
what the program, no matter what the language.
 Why UNICODE?
 No single encoding could contain enough
characters: for example, the European Union
alone requires several different encodings to
cover all its languages and what about Asian
languages with all there characters.
 Even for a single language like English no single
encoding was adequate for all the letters,
punctuation, and technical symbols in common
use.
Storage
Computer Concepts
Representation of Images

Digitized picture of a tiger.
Storage
Computer Concepts
Representation of Images

Black and white pixels are either 0 or 1.
0001000000000000000000000000000000000000010101
0100000000000000100000000000000000000000000101
0110000000000000100000000000000000000000000011
1010101000000000010000000000000000000000000011
1001000000000000101100000000000000000000000101
0100010000000000011110000000000000000000000111
0100100100000000011111010101011100000000000011
0001000000000000111101110111111101000000001011
0000101001000001101111101111110110000000001111
0000010100000000111110111101011101000000000111
0000010100100011101010101011010000000000010111
0000001010100000011101010101101010100000011111
0000010110000001010100100000000000000000001110
0000000000011001010100000000000000000000001111
0000000000010110010100000000000000000000101111
0010010101010100100101010000000000000001011111
1000001111110100101101110101011000000010110111
1001001111010111111111110101101101011111111111
0110010111110111111111111111111101111110111111
1010101101111111111111111111111111111111111111
1010000111011111111111111111111111111111111111
0101010011111111111111111111111111111111111111
0110000101011111111111111111101111110011110101
0101111011111111111111111111111011010101110101
1010101011111111111111111010110111101111011111
0000001011111111111101011101101001111110101010
0000001011111111111101111111110010111101101010
0000000111111010111110111011101001111110101010
0000000111111111111111010111111101111110111011
0000101111101101010110000101111111111111101011
Storage
Computer Concepts
Gray-Scale:
Each pixel contains a value representing
some shade of gray.
The more shades of gray possible, the more
memory will be needed.
4 shades of gray needs 2 bits per pixel:
00, 01, 10, 11
8 shades of gray needs 3 bits per pixel:
000, 001, 010, 011, 100, 101, 110, 111
64 shades of gray needs 6 bits per pixel:
000000, 000001, … 111110, 111111
Storage
Computer Concepts
Representation of Images


Representing colors
in pictures takes
even more bits than
gray-scale.
The more colors the
more bits and thus
more:
Memory is required
Processing power is required
A better graphics card is required
Storage

Computer Concepts
Fact: All types of information are stored in
binary form.
 Problem:
The computer has no way of
discerning between types unless a file is
marked in some manner for identification
by the operating system.
 Files
are marked as to type with unique
icons and have an extension that indicates
file type. (e.g., .doc, .txt, .html, .xls, .ppt,
.wav, .jpg and so forth)
Storage
Computer Concepts
Windows files showing their icons and extensions
Computer Concepts
Advantages of a computer

Communications
Allows us to easily share data
 Networks
 Email
 The Internet
 The World Wide Web
 Modern Wireless Devices
Cell
phones
WiFi and Bluetooth
Computer Concepts
Types of Computer Software
What is system software?

Programs that control the operations of the
computer and its devices
Operating
System (OS)
Next
p. 1.12
Utility
Programs
Computer Concepts
Types of Computer Software
The operating system (OS) on the
computers in the lab is Windows 2000
Professional.
Some other OS names are:
DOS (Disk Operating System)
Windows 98, Me, XP
Windows 2000 Active Server
Unix
Linux
Macintosh OS X and others
Computer Concepts
Types of Computer Software
What is application software?

Programs that perform specific tasks for users
Suite
Word
processing
software
Popular software applications
bundled together as a single
unit
Office XP
Spreadsheet
software
Database
software
Presentation
graphics
software
Computer Concepts
Types of Computer Software
There must be some type of (OS) system
software for application software to run on.
 The application software must be
compatible with the OS software.
 The application software we will work with
includes:
Word (Word processing)
Excel (Spreadsheets)
Access (Databases)
Internet Explorer (Web Browser)
M.S. Paint (Graphics)
Other

Computer Concepts
User Interface
What is the user interface?


p. 1.12
Controls how
you enter data
and commands
and how
information
displays
Types of user
interfaces
include
command line
and graphical.
Computer Concepts
User Interface
What is a graphical user interface (GUI)?

Uses visual images such as icons

Icons represent
programs,
instructions, or
some other
objects
p. 1.12 Fig. 1-13
icons
icons
Computer Concepts
The PC (Microcomputer) vs. Minis,
Mainframes, Supercomputers
Computers are
compared as to their:
Speed
Cost
Size
Complexity
Fast Expensive Complex Large
Super Computers
Mainframe Computers
Minicomputers
Microcomputers
Slow Cheap Simple Small
p. 1.12
Computer Concepts
The PC (Microcomputer) vs. Minis,
Mainframes, Supercomputers
 Microcomputers:
 Are single-user systems (PCs) – only one processor.
 Minicomputer:
 Most often used by several people (10 to hundreds of
users). Usually faster than a microcomputer but the
difference is rapidly fading.
 May have more than one processor.
 Mainframe:
 A powerful multi-user computer capable of supporting many
hundreds or thousands of users simultaneously.
 Has many processors
 Supercomputer:
p. 1.12
 An extremely fast computer that can perform hundreds of
millions of instructions per second.
 May have hundreds of processors
Computer Concepts
Computers have shrunk in size while getting more powerful
p. 1.12
Computer Concepts
Constructed out of electromagnetic
relays, rotating shafts, and
clutches.
Described as sounding like a
“roomful of ladies knitting”.
Contained more than 750,000
components, 50 feet long, 8 feet tall
and weighed 5 tons.
Harvard Mark I (IBM ASCC)
ENIAC took 200,000 man-hours to
build
Weighed 30 tons
Used 18,000 vacuum tubes (one
went out every 12 minutes)
1,000 times faster than the Harvard
Mark I
p. 1.12
ENIAC
Computer Concepts
Why do we say a computer has a bug?
p. 1.12

We owe that concept to Grace Hopper

A Naval officer, she was the third programmer on the Mark I

Considered the Mother of COBOL (Common Business
Oriented Language)

Found first computer bug - a moth stuck in the computer’s
electromagnetic relays and fouling it up.
Computer Concepts
 The invention of the transistor and
integrated circuits led to:
Smaller computers
Many more diverse capabilities and uses for
computers
Today’s Intel Pentium 4 chip has 25 layers and
55 million transistors in a chip about 3/8th of an
inch square
p. 1.12
Computer Concepts
“That’s all folks!”
p. 1.12