Transcript Lesson 1 - cloudfront.net

Lesson 1
Computers and Computer Systems
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Understand the importance of computers.
Define computers and computer systems.
Classify computers.
Use computer systems.
Identify system components.
Identify types of storage devices.
Care for storage media.
Explore computers in your future.
Objectives
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• Arithmetic/logic unit (ALU): Performs arithmetic
computations and logical operations.
• Central processing unit (CPU): Also called the
microprocessor or central processor, is the brains of the
computer.
• Circuit board: A thin plate or board that contains electronic
components.
• Computer: An electronic device that receives data (input),
processes data, stores data, and produces a result (output).
• Control unit: The boss, so to speak, and coordinates all of the
processor’s activities.
• Data: Text, numbers, sound, images, or video.
• Hard disk: Used to store data inside the computer, although
external hard disks are also available.
Vocabulary
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• Hardware: The actual machine—wires, transistors, and
circuits.
• Information: Output.
• Memory: Where data is stored on the motherboard.
• Mobile device: Computers that can fit into the palm of
your hand.
• Motherboard: A circuit board that contains many
integral components.
• Notebook computer: Today’s most widely used personal
computer, designed for one person to use at a time.
Vocabulary
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• Random access memory (RAM): The main memory or
primary memory on the motherboard.
• Read-only memory (ROM): The permanent storage of data,
usually burned onto chips.
• Server: A computer generally used by small to medium-size
companies and can support a few users or hundreds of users.
• Software: Consists of instructions or programs for controlling
the computer.
• Supercomputer: The fastest type of computer used to process
enormous amounts of data.
• Tablet PC: A personal computer similar in size and thickness
to a notepad.
• USB flash drive: A small removable data storage device.
Vocabulary
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Invention of Computer
• The computer is one of the most important
inventions of the past century.
• You find computers and computer technology
everywhere throughout society—from businesses
and financial organizations, to home electronics
and appliances, and to personal applications such
as clothing embedded with iPod controls.
Understanding the
Importance of Computers
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A Brief History of the Computer
• The first computers were developed in the late 1940s
and early 1950s for use by the military and
government.
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UNIVAC and ENIAC
Less processing power than an iPhone
Occupied a small building or city block
Cost millions of dollars
• Computers in mid 50s—70s were smaller and more
powerful but still limited
Understanding the
Importance of Computers
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A Brief History of the Computer (cont.)
• In 1971, Dr. Ted Hoff developed the
microprocessor.
• The first Apple computer was built in 1976 by
Steve Jobs and Steve Wozniak. The IBM PC was
introduced in 1981.
Understanding the
Importance of Computers
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FIGURES on PAGES Mod 1-4 & 1-5
• Students doing online research
• Early computers
• The Apple II and IBM PC
Understanding the
Importance of Computers
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• Above and Beyond: The first IBM PC ran
on a 4.77 MHz Intel 8088 microprocessor.
The PC came equipped with 16 kilobytes
(KB) of memory, expandable to 256 KB.
The PC came with one or two 160KB
floppy disk drives and an optional color
monitor.
Understanding the
Importance of Computers
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• A computer is an electronic device that
receives data (input), processes data, stores
data, and produces a result (output).
• A computer system includes hardware,
software, data, and people.
• The actual machine—wires, transistors,
and circuits—is called hardware.
Defining Computers and
Computer Systems
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• Software consists of instructions or
programs for controlling the computer.
• Data is text, numbers, sound, images, or
video.
• The computer receives data through an
input device, processes the data, produces
the output (or information), and stores the
data and information on a storage device.
Defining Computers and
Computer Systems
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FIGURES on PAGES Mod 1-6 & 1-7
• Using a mobile computer to process data
into information
• Information processing cycle
• Consists of four steps: I-P-O-S
Defining Computers and
Computer Systems
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• Above and Beyond: Deep Blue was a
chess-playing computer developed by
IBM. On May 11, 1997, the machine won
a six-game match by two wins to one with
three draws against world champion Garry
Kasparov.
Defining Computers and
Computer Systems
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• Special-purpose computers are used
mostly to control something else.
• Dishwashers
• Bathroom Scales
• Airport Radar Systems
• General-purpose computers are
divided into categories, based on their
physical size, function, cost, and
performance.
Classifying Computers
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• Types General Purpose
Computers
• Desktop and
Notebook/Laptop are
today’s most widely used
personal computers, which
are designed for one person
to use at a time.
• PCs and Macs
All-in-One
Smaller version
of laptop
• Tablet PCs are similar in
size to a notepad. They
function as a PC as well as a
portable note-taking device.
• Mobile devices fit in the
palm of your hand.
• Calculators, Smartphones,
electronic organizers, etc.
Classifying Computers
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• Types of computers (cont.)
• Servers are used by small/medium
companies to support few to hundreds
of users. Usually referred to as
network/application servers.
• Web = delivers web pages
• Database = stores/manages database info
• File = stores remote programs and files that
can be shared by users
• Mainframe computers are a large,
expensive computer capable of
supporting hundreds/thousands of
users.
• Supercomputers are the fastest types
of computers. These are used by the
Government and large corporations.
• Cost = millions of dollars
Classifying Computers
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FIGURE on PAGE 1-10
• Electronic book reader
• Nook, Kindle, etc.
• Above and Beyond:
Supercomputers are often
used to conduct and test
medical experiments
Classifying Computers
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• Computers are used for all kinds of tasks.
• Computers take raw data and change it into
information. An example of the procedure:
• You enter programs and data with some type of
input device.
• The computer uses instructions to process the
data and to turn it into information.
• You send the information to some type of
output device.
• You store it for later retrieval.
Using Computer Systems
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• Technology Careers - Computers on the Job:
In the past few decades, computers have had
dramatic effects on how we live, learn, and work.
For example, the kinds of jobs available have
changed because of computers. Fifty years ago,
only a handful of people were computer
programmers, and none were Web designers or
software entrepreneurs. Today, nearly all jobs
require some computer skills.
Using Computer Systems
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• Time-consuming, labor-intensive communication tasks
that used to require face-to-face meetings, telephone
calls, overnight deliveries, or paging through printed
materials are now performed quickly and efficiently using
Internet browsers and e-mail. Students can participate in
distance-learning classes to take courses not available
where they live. Even the electric-meter reader and
delivery person now carry hand-held computers that track
a consumer’s electricity use or the location of a package.
Cashiers use computers for retail sales, and managers use
them to update the store’s inventory, handle customer
calls, and advertise products. All of these advances, now
taken for granted by many of us, are recent innovations.
Using Computer Systems
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FIGURE on PAGE
Mod 1-11
• Computer system
components
contained within the
system’s case
Using Computer Systems
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• The motherboard, or
system board, is a
circuit board that
contains integral
components —
central processing
unit, memory,
connectors, and
expansion ports and
slots.
Identifying System
Components
Motherboard
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The Central Processing Unit
• The central processing unit (CPU) is the brains of the
computer. It is housed on a tiny silicon chip.
• Contains millions of switches and pathways
• Dual-core contains two separate processors on a single chip
• Multicore is expansion for more than two (2) separate
processors
• Speeds are generally measured in Gigahertz
• Current speeds are 2GHz – 4GHz
Identifying System
Components
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The Central Processing Unit (cont.)
• The CPU has two primary sections: the arithmetic/logic unit and
the control unit.
• The Arithmetic/Logic Unit (ALU)
• Performs arithmetic computations
• Addition, Subtraction, Multiplication, and Division
• Performs logical operations
• Comparisons (AND, OR, NOT)
• Two numbers equal or if one number is greater than or less than
another number
• Can execute complex tasks by combining arithmetic and logical
operations,
• Video Games use arithmetic operations and comparisons to determine
what appears on screen
Identifying System
Components
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• The Control Unit
• The control unit coordinates all of the processor’s activities.
• You communicate with the computer through programming
languages.
• The computer uses machine language, or binary code, which contains
only 1s and 0s.
• Communicate with computer via programming languages:
• Java
• COBOL
• C++
Identifying System
Components
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Recognizing How a Computer Represents Data
• Control Unit reads and interprets program
instruction into machine language. When
electricity travel through processor pathways, it
turns switches on and off. This represents the 1s
and 0s.
• Electricity Present = 1
• Electricity Absence = 0
Identifying System
Components
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Recognizing How a Computer Represents Data
(cont.)
• The control unit sends out necessary messages to
execute the instructions. A single zero (0) or a
single one (1) is a bit, which
is the smallest unit of
information storage. A
byte is a single character,
such as a letter or number.
Identifying System
Components
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Memory
• Memory is where data is stored on the
motherboard.
• Memory can be short term or long term.
• When you want to store a file or information
permanently, you use secondary storage devices
such as the computer’s hard drive or a USB
drive. You might think of this as long term
memory.
Identifying System
Components
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Random Access Memory
• The memory on the motherboard is short term, called random
access memory (RAM).
• Data, information, and program start-up instructions are
stored temporarily on a RAM chip and disappear when the
computer is turned off or there is a power loss.
• The instruction cycle is the amount of time it takes to retrieve
instructions to perform a specified task and complete the
command.
• The execution cycle refers to the amount of time it takes the
CPU to execute the instruction and store the results in RAM.
Identifying System
Components
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Random Access Memory (cont.)
• Together, the instruction cycle and one or more execution
cycles create a machine cycle.
• For every instruction, a processor repeats a set of four
basic operations, which compose a machine cycle
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Fetching – Obtaining a program instruction or data from RAM
Decoding – Process of translating the instruction into signals
Executing – Process of carrying out commands
Storing – Writing result to memory
Identifying System
Components
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Processing
Cycle
Identifying System
Components
Machine
Cycle
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Read-Only Memory
• Another type of memory found on the motherboard is read-only
memory (ROM).
• ROM chips store specific instructions that are needed for
computer operations. These instructions remain on the chip even
when the power is turned off, because ROM chips are
nonvolatile.
• The more common of these is the BIOS ROM, containing
instructions to start the system when you turn on the computer.
Identifying System
Components
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• Above and Beyond: Cache memory is another type of
memory. This high-speed RAM is used to increase the
speed of the processing cycle.
• Above and Beyond: If you read computer ads, you are
likely to see the abbreviations MHz (megahertz) and GHz
(gigahertz). These speed specifications indicate the speed
of the microprocessor clock—a timing device that
specifies the speed for executing instructions.
• Above and Beyond: In the time it takes to blink your
eyes, certain computers can perform certain operations 10
billion times.
Identifying System
Components
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Motherboard
Microprocessor
RAM
Identifying System
Components
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To keep a permanent copy of data, you must store it on a storage
device.
• Magnetic Storage Devices
• Data is stored in numbered tracks in a special log on the disk called a
file allocation table (FAT).
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Hard Disks
Magnetic Tape
Zip Disks
3½” Disks
• Hard Disks (aka: Hard Drives)
• Store data inside computer, or outside via external HD
• Advantages: speed and capacity.
• Measured in Gigabytes or Terabytes
Identifying Types of
Storage Devices
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• Removable Disks
• Removable magnetic media are rarely used and include 3½” disks and
Zip disks.
• Optical Storage Devices
• Use laser technology to read and write data on plastic platters that
contain a metal layer, like CDs, DVDs, etc.
• CD-DA = audio CD
• CD-R = Write once CD
• CD-ROM = Store up to 1 GB but common size is 650 MB or 74
minutes
• CD-RW = Rewritable CD; erase data and write multiple times
• DVD-ROM = Movies and Games; Capacities from 4.7–17 GB
• DVD-R = Write once DVD
• DVD-RW = Rewritable DVD; erase data and write multiple times
• Blu-Ray = 5 times storage capacity of DVD; Capacities from 25-50 GB
Identifying Types of
Storage Devices
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• Solid-State Storage Media
• Nonvolatile, removable medium that uses integrated circuits
• USB flash drive
• SD Cards
• Compact Flash Card
• Network Drives
• Hard drive or tape drive located on computer other than user’s
computer
• Connected to a network server and is available to and shared by
multiple users.
• Remote storage is used to extend disk space on a server and to
eliminate the addition of more hard disks or other storage devices.
Identifying Types of
Storage Devices
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• Above and Beyond: Blu-ray optical discs
use a blue-violet laser to read and write
data, unlike earlier optical discs such as
DVDs, which use a red laser. Although
they use different lasers, Blu-ray products
can be backwards compatible with CDs
and DVDs.
Identifying Types of
Storage Devices
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Platter
Spindle
Head
Actuator Arm
Actuator
Identifying Types of
Storage Devices
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Exploded View
of 3½” Disk
Write Protection Tab
Housing
Hub
Magnetic
Disk
Paper Ring
Plastic
Flap
Shutter
Identifying Types of
Storage Devices
Spring
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Miniature Mobile Storage Media
Identifying Types of
Storage Devices
Examples of
USB Flash
Drives
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• Keep away from magnetic fields.
• Avoid extreme temperatures.
• Remove media from drives and store them
properly when not in use.
• When handling DVDs and other optical discs,
hold them at the edges.
• Never try to remove the media from a drive when
the drive indicator light is on.
• Keep discs in a sturdy case when transporting.
Caring for Storage Media
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• A major focus of new types of computers is
connectivity, or the ability to connect with other
computers.
• Wireless and mobile devices are now as common
as wired desktop machines.
• Computer literacy, which is the knowledge and
understanding of computers and their uses, will
become even more important.
Exploring Computers in
Your Future
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1) Who built the first Apple computer?
Answer: Steve Jobs and Steve Wozniak
2) True or False? Many people consider the computer to be
the single most important invention of the 20th century.
Answer: True.
3) True or False? Machines like the UNIVAC and ENIAC
were designed initially for use by schools.
Answer: False. Machines like the UNIVAC and ENIAC
were designed initially for use by the military and
government.
QUICK QUIZZES
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4) A computer __________ includes hardware, software, data, and
people.
Answer: system
5) __________ is text, numbers, sound, images, or video.
Answer: Data
6) Which type of computer is designed for one person to use at a
time?
A. personal computer
B.
server
Answer: A
7) Tiny chips embedded in dishwashers, bathroom scales, or airport
radar systems are classified as __________ computers.
A. general-purpose
B.
special-purpose
Answer: B
QUICK QUIZZES
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8) True or False? Just about all computers, regardless of
size, take raw data and change it into information.
Answer: True.
9) The __________ that the computer uses to process data
are contained within the system case.
Answer: components
10) Computers follow the __________ procedure—input,
processing, output, and storage.
Answer: IPOS
QUICK QUIZZES
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11) The central processing unit (CPU), also called the
microprocessor or central processor, is the __________ of the
computer.
Answer: brains
12) True or False? The arithmetic/logic unit (ALU) is the boss of
the CPU.
Answer: False. The arithmetic/logic unit (ALU) performs
arithmetic computations and logical operations.
13) True or False? The computer does not understand human
language.
Answer: True.
14) A __________ is the smallest unit of information storage.
Answer: bit
QUICK QUIZZES
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15) True or False? Random access memory, or RAM, is
considered short term memory.
Answer: True.
16) __________is the process of obtaining a program instruction
or data item from RAM.
Answer: Fetching
17) __________ is a nonvolatile, removable medium that uses
integrated circuits.
A. Optical storage
B. Magnetic storage
C. Solid-state storage
D. None of the above
Answer: D
QUICK QUIZZES
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18) True or False? Most hard disks are used to store data
inside the computer.
Answer: True.
19) True or False? A network drive is located on a computer
other than the user’s local system.
Answer: True
20) True or False? You should hold DVDs at the edges.
Answer: True.
QUICK QUIZZES
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21) True or False? It is okay to remove media from a drive
when the drive indicator light is on.
Answer: False.
22) True or False? Wireless and mobile devices are not as
common as wired desktop machines.
Answer: False.
23) True or False? Computer literacy is the knowledge and
understanding of computers and their uses.
Answer: True.
QUICK QUIZZES
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