Computer Concepts A Brief Introduction
CAS 133 – Basic Computer Skills/MS Office XP
Russ Erdman - Instructor
“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
Computer ConceptsWhat are data and information?
DataRaw facts,
figures, and symbols
InformationData that is organized,
meaningful, and useful
SoftwareInstructions that
tell hardware how to perform tasks
HardwareElectronic and
mechanical equipment
What are hardware and software?Computer Concepts
Computer ConceptsHardware, Software and the
Computer
Without SOFTWARE the computer HARDWARE is just a giant PAPER WEIGHT!
What are common computer hardware components?
printer
scanner
speakerPC camera
microphonedigital camera
system unit
keyboard
modem
monitor
mouse
speaker
Computer Concepts
What is an input device?
Hardware used to enter data and instructions.
scanner
microphone
keyboard
mouse
PC camera
digital camera
Computer Concepts
What is an output device? Hardware that conveys information to a user.
printer
monitor speakers
Computer Concepts
What is the system unit?
Box-like device containing electronic components connected to motherboard hard
disk drive(inside case)
CD-RW drive
CD-ROM or DVD-ROM drive
Zip® drive
floppy disk drive
Computer Concepts
Processor Memory module
Processor Memory module Expansion cards
• Sound card• Modem card• Video card• Network
interface card
Ports and Connectors
Processor Memory module Expansion cards
• Sound card
Processor Memory module Expansion cards
• Sound card• Modem card
Processor Memory module Expansion cards
• Sound card• Modem card• Video card
Processor Memory module Expansion cards
• Sound card• Modem card• Video card• Network
interface card
Processor
What are common components insidethe system unit?
Computer Concepts
What is the motherboard? Main circuit board
in system unit Contains
chips,integrated circuits,and transistors
Also calledthe system board
Computer Concepts
Memory (RAM & ROM)• Temporary holding place for data
and instructions
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
Computer Concepts
Central Processing UnitCentral Processing UnitWhat is a microprocessor?
Single processor chip foundin personal computers
Computer Concepts
Computer Concepts
volatile memoryLoses its contents when Loses its contents when the computer's power is the computer's power is
turned offturned off
volatile memoryLoses its contents when
computer's poweris turned off
MemoryMemoryWhat are two types of system unit memory?
nonvolatile memory
Does NOT lose its contents when
computer’s power is turned off
p. 4.16
RAM
ROM
MemoryMemoryWhat is random access memory (RAM)?
p. 4.16
Memory chips that can be read from and written to by processor
Most RAM is volatileThe more RAM a computer has, the faster it
operates
memory module
Computer Concepts
What is storage? Holds data, instructions, and information for future use.
StorageDevice
• Records and retrieves items to and froma storage medium
Storage Medium
• Physical material on which data, instructions, and information are stored
Click to view Web Linkthen click Storage Devices
p. 1.7
Computer Concepts
CD-RW drive
hard disk drive
CD-ROM or DVD-ROM drive
ZIP® drivefloppy disk drive
What are common storage devices or drives?
p. 1.7 Fig. 1-3
Computer Concepts
What is a floppy disk?
Thin, circular, flexible disk enclosed inrigid plastic
A Zip® disk is a higher capacity disk
Computer Concepts
Computer Concepts
p. 7. 10 Fig. 7-12
What is a hard disk? High-capacity
storage Consists of
several inflexible, circular platters that store items electronically
Components enclosed in airtight, sealed case for protection
hard disk installed in system unit
4: Head actuator positions read/write head arms over correct location on platters to read or write data
Step 4
2: Small motor spins platters
Step 2
3: When software requests disk access, read/write heads determine location of data
Step 3
1: Circuit board controls movement of head activator and small motor
Step 1
p. 7.11 Fig. 7-13
Hard DisksHow does a hard disk work?
Computer Concepts
Computer Concepts
p. 7. 17
Compact DiscsWhat is a compact disc (CD)?
Storage medium
Most PCs include some type of compact discdrive
Available invariety offormats
CD-ROM
CD-RCD-RW
DVD-ROM
DVD+RW
Computer ConceptsCompact Discs
A CD-ROM’s layout.
Computer ConceptsComputer SoftwareWhat is a computer program? A series of instructions that tells the
computer what to do
p. 1.10
Computer ConceptsAdvantages of a computer
SpeedReliabilityAccuracyStorageCommunications
Computer Concepts
SpeedOperates at close to the speed of light –
186,000 miles/second! Consider word processing (typing) over
writing by hand. Reliability
Hardware seldom failsWhen the bank says the computers are
down it may not be true.
Advantages of a computer
Computer Concepts
AccuracySoftware – GIGO (Garbage In Garbage Out) Humans make 1 error every 300 characters
typed, computers make 1 error every 3,000,000 characters processed.
StorageConcept 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!
Advantages of a computer
Five basic types of data are represented in the computer.NumericCharacterVisualAudio Instructional
Computer ConceptsStorage
Data RepresentationData Representation
Computer Concepts
Data RepresentationData RepresentationHow do computers represent data?
Most computers are digital
Recognize only two discrete states: on or off
1 1 1 1 1
0 0 0 0 0
on
offp. 4.13
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).
Storage
Computer Concepts
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 booksZip Disk = 100,000,000 bytes = 250 booksCD = 700,000,000 bytes = 1,750 booksDVD = 4,200,000,000 bytes = 10,500 booksHard Drive (small in lab) = 6,000,000,000
bytes = 15,000 booksHard Drive (newer) = 100,000,000,000 bytes =
250,000 books
Storage
Computer ConceptsStorageRepresenting 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.
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.
Computer ConceptsStorage
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
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
A partial listing of the ASCII character set
Computer ConceptsStorage 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.
Computer ConceptsStorage
Digitized picture of a tiger.
Representation of Images
Computer ConceptsStorage
Black and white pixels are either 0 or 1.000100000000000000000000000000000000000001010101000000000000001000000000000000000000000001010110000000000000100000000000000000000000000011101010100000000001000000000000000000000000001110010000000000001011000000000000000000000001010100010000000000011110000000000000000000000111010010010000000001111101010101110000000000001100010000000000001111011101111111010000000010110000101001000001101111101111110110000000001111000001010000000011111011110101110100000000011100000101001000111010101010110100000000000101110000001010100000011101010101101010100000011111000001011000000101010010000000000000000000111000000000000110010101000000000000000000000011110000000000010110010100000000000000000000101111001001010101010010010101000000000000000101111110000011111101001011011101010110000000101101111001001111010111111111110101101101011111111111011001011111011111111111111111110111111011111110101011011111111111111111111111111111111111111010000111011111111111111111111111111111111111010101001111111111111111111111111111111111111101100001010111111111111111111011111100111101010101111011111111111111111111111011010101110101101010101111111111111111101011011110111101111100000010111111111111010111011010011111101010100000001011111111111101111111110010111101101010000000011111101011111011101110100111111010101000000001111111111111110101111111011111101110110000101111101101010110000101111111111111101011
Representation of Images
Computer ConceptsStorage
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
Computer ConceptsStorage
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 requiredA better graphics card is required
Representation of Images
Computer ConceptsStorage
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)
Computer ConceptsStorage
Windows files showing their icons and extensions
Computer Concepts
CommunicationsAllows us to easily share data
NetworksEmailThe InternetThe World Wide WebModern Wireless Devices
Cell phonesWiFi and Bluetooth
Advantages of a computer
Computer ConceptsTypes of Computer SoftwareWhat is system software? Programs that control the operations of the
computer and its devices
Operating System (OS)
Utility Programs
p. 1.12
Next
Computer Concepts
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, XPWindows 2000 Active ServerUnixLinuxMacintosh OS X and others
Types of Computer Software
Computer ConceptsTypes of Computer SoftwareWhat is application software?
Programs that perform specific tasks for users
Word processing
software
Spreadsheet software
Database software
Presentation graphics software
SuitePopular software applications bundled together as a single
unit
Office XP
Spreadsheet Database
Presentation graphics
Word processing
Computer ConceptsTypes 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
What is the user interface?
Controls how you enter data and commands and how information displays
Types of user interfaces include command line and graphical.p. 1.12
User Interface
Computer Concepts
p. 1.12
User InterfaceWhat is a graphical user interface (GUI)?
Uses visual images such as icons Icons represent
programs, instructions, or some other objects
icons
icons
p. 1.12 Fig. 1-13
Computer Concepts
p. 1.12
Computers are compared as to their:SpeedCostSizeComplexity
Super Computers
Mainframe Computers
Minicomputers
Microcomputers
Fast Expensive Complex Large
Slow Cheap Simple Small
The PC (Microcomputer) vs. Minis, Mainframes, Supercomputers
Computer Concepts
p. 1.12
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: An extremely fast computer that can perform hundreds of millions of
instructions per second. May have hundreds of processors
The PC (Microcomputer) vs. Minis, Mainframes, Supercomputers
Computer Concepts
p. 1.12Computers have shrunk in size while getting more powerful
Computer Concepts
p. 1.12
Harvard Mark I (IBM ASCC)
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.
ENIAC
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
Computer Concepts
p. 1.12
Why do we say a computer has a bug? 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
p. 1.12
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
Computer Concepts
p. 1.12
“That’s all folks!”