Computers and Computer Systems

Computing Fundamentals 1

Computers and Computer Systems

Computing Fundamentals IC3


Major Unit Concepts Understand the importance of computers. Define computers and computer systems. Classify computers. Use computer systems. Identify system components. Identify types of storage devices. Explore computers in your future.


Vocabulary arithmetic/logic

unit (ALU) central

processing unit (CPU)

circuit board computer control unit Data

hard disk hardware information memory mobile device motherboard notebook

computer


Vocabulary random access memory

(RAM) read-only memory

(ROM) server software supercomputer tablet PC USB flash drive


Understanding the Importance of Computers The computer is one of the most important

inventions of the past century. You find computers and computer

technology everywhere—from businesses and financial organizations, to home electronics and appliances, to personal applications.


Understanding the Importance of Computers (continued)

Computers are used everyday: Educational institutions use computers to enhance

instruction and learning. Video game systems are computerized. Banks use ATM’s so you can withdrawal money from

you bank account in almost any location in the world.

Computers are used by television and at the movies. Mobile computing, text messaging, or email allow

you to communicate with people almost everywhere.


Understanding the Importance of Computers (continued)

Computers have been around for more than 60 years. 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.

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 by Bill Gates. He worked with IBM to develop the first Disk Operating System.


Defining Computers and Computer Systems 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.


Defining Computers and Computer Systems (continued) The actual machine—wires, transistors, and

circuits—is called hardware. 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, process the data, produces the output (or information), and stores the data and information on a storage device.


Defining Computers and Computer Systems (continued)

Computers perform only 2 operations: Arithmetic Computations: addition,

subtraction, multiply, divide, and comparisons.

Logical Operations: AND, OR, and NOT


Classifying Computers Special-purpose computers are used mostly

to control something else. General-purpose computers are divided into

categories, based on their physical size, function, cost, and performance:

Desktop and notebook computers

Server Mobile devices Tablet PC Mainframe computer

Supercomputer Embedded computers Portable players Calculators Computer game systems Electronic book readers


Using Computer Systems Computers are used for all kinds of tasks.

They 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 (continued)

Computer components


Identifying System Components The motherboard is a circuit board that

contains integral components—central processing unit, memory, connectors, and expansion ports and slots.


Identifying System Components (continued)

The Central Processing Unit: The central

processing unit (CPU) is the brains of the computer.

The CPU has two primary sections: the arithmetic/logic unit and the control unit.


Identifying System Components (continued) The Arithmetic/Logic Unit: The arithmetic/logic unit (ALU) performs

arithmetic computations and logical operations. 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.


Identifying System Components (continued)Recognizing How a Computer Represents Data: In machine language, the control unit sends out

necessary messages to execute the instructions. A single zero or a single one is a bit. A byte is a single character. Each bit is equal to 1 byte.



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.



Random Access Memory The memory on the motherboard is short

term, called random access memory (RAM). Data, information, and program instructions

are stored temporarily on a RAM chip and disappear when the computer is turned off.



Random Access Memory (cont) 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.



Random Access Memory (cont) Together, the instruction cycle and one or

more execution cycles create a machine cycle.



Random Access Memory (cont): For every instruction, a processor repeats a set of

four basic operations, which compose a machine cycle:

1. Fetching is the process of obtaining a program instruction or data item from RAM

2. Decoding refers to the process of translating the instruction into signals the computer can execute.

3. Executing is the process of carrying out the commands.

4. Storing, in this context, means writing the result to memory (not to a storage medium).


Identifying System Components (continued) Random Access Memory (cont):


Identifying System Components (continued) 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.

The more common of these is the BIOS ROM, containing instructions to start the system when you turn on the computer.


Identifying Types of Storage Devices

To keep a permanent copy of data, you must store it on a storage device.

Magnetic Storage Devices: Data is stored in numbered Tracks. Tracks are labeled and kept in a special

log on the disk called a file allocation table (FAT).

Types of magnetic storage media include hard disks, magnetic, tape, 3 ½ -inch disks and zip disks.


Identifying Types of Storage Devices

Hard Disks: Also called hard drives Store date inside the computer Can be internal or external Internal hard disks advantages: speed and

capacity Size measured in gigabytes or terabytes.


Identifying Types of Storage Devices (continued)

Optical Storage Devices:

Use laser technology to read and write data on plastic platters that contain a metal layer, like CDs and DVDs.

CD-R - Can be ready only by CD-ROM drive. After it is written, it cannot be changed.

CD-RW- Rewritable type that allows you to write on it several times.

Blu-Ray – Provides more than 5 times the storage capacity of traditional DVD’s. Can hold up to 50 GB and was developed for HD videos.



Solid-State Storage Media Removable medium that uses integrated circuits, such as

a USB flash drive. Processed electronically and contains no mechanical

devices. Can be used in cameras, smart phones, and computers. USB flash drive is most popular removable storage device.



Network Drives Hard drive or tape drive connected to a

network server and is available to and shared by multiple users.

Located on a computer other than the local user’s computer.

Remote storage is used to extend disk space on a server and to eliminate the addition of more hard disks or other storage devices.


Caring for Storage Media 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.


Exploring Computers in Your Future

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.


Assignments

TIC-TAC-TOE Directions: Chose activities in a tic-tac-toe design.

When you have completed the activities in a row—horizontally, vertically, or diagonally—or in the 4 corners, you made decide to be finished. Or you may decide to keep going and complete more activities.

Star the activities you plan to complete. Color in the box when you finish the activity.

Discuss and provide Feedback to TIC-TAC-TOE Review Take end of section quiz


Continue on to next section

Computers and Computer Systems 34

Input, Output, and Processing



Major Unit Concepts

Identify and describe standard and specialized input devices.

Identify and describe standard and specialized output devices.

Connect input and output devices to a computer.

Consider computer performance factors.


Vocabulary

audio input biometrics digital camera expansion slot FireWire inkjet printer input

keyboard laser printer modem monitor mouse output plug and play


Vocabulary (continued)

pointing device port printer scanner trackball Universal Serial Bus (USB)


Standard Input Devices

Input , which is data , must be entered into computer and then stored on a storage media device.

To turn the data into information, CPU (Central Processing Unit) processes the data.

After data is processed, it is “presented” to the user through an output device.


Standard Input Devices (continued)

Input devices allow you to enter data and commands.

A modem is a device that allows one computer to talk to another.

Keyboards The keyboard is the most commonly

used input device for entering text and numbers into a computer.


Standard Input Devices (continued)

Keyboards (continued): Ergonomic Cordless/wireless Specialized Security Foldable/flexible Laser/virtual


Standard Input Devices (continued) Pointing Devices: A pointing device is an input device you

use to position the pointer on the screen.

The most common pointing device for personal computers is the mouse.

Mechanical Optomechanical Optical Wireless Trackball mouse Radio frequency Foldable mouse


Standard Input Devices (continued) Pointing Devices (continued): The trackball works like a mouse turned

upside down; the ball is on top of the device.

A common feature on laptop computers is the touchpad, with a specialized surface that can convert the motion and position of your fingers to a relative position on screen.


Standard Input Devices (continued) Pointing Devices (continued): Some notebook computers contain a

pointing stick, a pressure-sensitive device that looks like a pencil eraser and is located on the keyboard, generally between the G, H, and B keys.

Audio input is sound entered into a computer.


Standard Output Devices Output is data processed into a useful

format. Monitors: Desktop computers typically use a monitor

as their display device, including CRT, LCD, and gas plasma.


Standard Output Devices (continued) Printers: Printers produce a paper copy, or hard

copy, of processing results. A laser printer produces high-quality

output. An inkjet printer provides good-quality color

printing for less expense. Speakers: Speakers and headsets generate sound.


Specialized Input Devices Digital Cameras: The pictures you take are stored digitally

and then transferred to the computer’s memory.


Specialized Input Devices (continued)

Game Controllers: You use joysticks and wheels most

often for games.


Specialized Input Devices Scanners/Bar Code Readers: Scanners are devices that can change

images into codes for input to the computer. Image scanners Bar code scanners Magnetic scanners Wireless scanners Optical character recognition (OCR) and

optical mark recognition (OMR) scanners


Specialized Input Devices (continued) Touch Display Screen: A special screen that reacts to direct

touches within the display area, usually from a person’s finger or hand.


Specialized Input Devices (continued) Stylus: A stylus and digital

pen are pen-like writing instruments used to enter information by writing on a screen on a mobile device or using the pen as a pointer.


Specialized Input Devices (continued) Environmental Probes and Sensors: Workers can view information such as the

temperature and humidity of a remote environment, smoke detector readings, and pollution control readings.

Remote Controls: Used to manage devices such as

televisions, lights, and fans.


Specialized Input Devices (continued) Security Devices: Biometrics is an authentication technique

using automated methods of recognizing a person based on a physiological or behavioral characteristic. Enrollment Submission Verification


Specialized Input Devices (continued) Virtual Devices: Use the synchronized positioning of light-

emitting and sensing devices to detect user input.


Specialized Input Devices (continued) Touch-Sensitive Pads: On a portable device, enables you to scroll

through a list, adjust the volume, play music, view videos or pictures, and customize settings.

Input Devices for the Physically Challenged:

A variety of special input devices are available for the physically challenged.


Specialized Output Devices Projectors Fax machines and fax modems Multifunction printer Control devices/robots

Specialized Printers: Thermal Mobile Label and postage Plotters/large-format


Specialized Output Devices (continued)

Output Devices for the Physically Challenged: Screen magnifiers Screen readers Voice synthesizers


Connecting Input and Output Devices to a Computer Ports and Connectors: A port, also called a jack, is an interface to

which a peripheral device attaches to or communicates with the system unit or other peripheral devices.

A Universal Serial Bus (USB) port can connect up to 127 peripheral devices with a single connector and transfer data at rates of up to 200 million bits per second (Mbps).

Plug and play refers to the ability of a computer system to configure expansion boards and other devices automatically.


Connecting Input and Output Devices to a Computer (continued) Ports and Connectors (continued): Another type of external bus is FireWire, which

supports data transfers up to 400 Mbps and can connect up to 63 external devices.

Special-purpose ports are: SCSI IrDA Bluetooth

Expansion slots are openings on the motherboard where an expansion board can be inserted.


Connecting Input and Output Devices to a Computer (continued) Hardware Installation: For most hardware devices to work, they

need a set of instructions that communicates with the computer’s operating system. This set of instructions is called a driver.

If the operating system already contains the driver, it performs an automatic plug and play, installation for newly connected devices.


Considering Computer Performance Factors A variety of factors can affect a computer’s

performance. Microprocessor: The higher the

generation, the faster and better the processing speed.

Random Access Memory (RAM): Helps to speed up the processing cycle.

Hard disk: The bigger and faster the hard drive, the faster it can process data.

Video: Need adequate video memory.

Assignments







Continue to the Next Section:

Computers and Computer Systems 63

Computer Protection



Major Unit Concepts Protect from hardware from theft. Data Protection Identify environmental factors that can

damage computers. Identify common hardware problems.


Vocabulary backup data theft driver encryption humidity ping power spikes surge suppressor

uninterruptible power supply (UPS)


Protecting Computer Hardware from Theft and Damage In addition to the capital loss of equipment

and the related down time until it is replaced, losing sensitive and confidential information through theft or damage could have long-term consequences.

One safeguard you can use to prevent theft in the workplace is to physically secure equipment, especially items such as notebook computers, handheld devices, cell phones, and other transportable devices.


Protecting Computer Hardware from Theft and Damage (continued)

In addition, apply the following safeguards to help protect computer hardware from theft: Use security locks and/or tabs to secure the

equipment to the desk or other furniture. Attach an alarm that will sound if the equipment

is moved from its designated location. Mark all equipment with an identification tag or

symbol that can be traced. Insure the equipment. Use a designated schedule to back up data to a

separate system.


Protecting Computer Hardware from Theft and Damage (continued)

Another type of theft that is sometimes overlooked involves employees accessing in a company’s computer for personal use.


Safe Guarding Data

Data Thieves steal laptops and servers, they can access company’s network and bypass companies security measures.

Data theft can occur when older systems are discarded and the data is not completely deleted.


Safeguarding Data In most instances, hardware can be replaced when it

is stolen or damaged. Data, on the other hand is a critical component of

most businesses and is not easily replaced. The risk and severity of data theft is increasing due

to four predominant factors: The value of data stored on computers. Massive amounts of confidential data being

stored. Increased use of mobile devices outside a secure

network. Increased proficiency of data hackers and

thieves.


Safeguarding Data (continued) Many businesses and organizations use data

encryption to protect their data. Encryption is a secure process for keeping confidential information private. The data is scrambled mathematically with a password or a password key and is unreadable until it is decrypted.


Safeguarding Data (continued)

Data Backup: Even saved data can be lost or corrupted by:

Equipment failure Software viruses Hackers Fire or water damage Power irregularities

Because data is so valuable, you must back up important files regularly to removable disks or some other independent storage device.


Safeguarding Data (continued) A hard disk crash can result in serious loss

of data if not properly backed up. Backup procedures should place priority on

files that would be difficult or impossible to replace or reconstruct if they were lost, such as a company’s financial statements, important projects, and works in progress.


Identifying Environmental Factors that Can Damage Computers Environmental factors such as temperature,

humidity, and electrical fields also can contribute to hardware and software damage.

Temperature: A temperature range of 68 to 75 degrees is

optimal for system reliability. You should not operate computer

equipment in a room where the temperature exceeds 85 degrees.


Identifying Environmental Factors that Can Damage Computers (cont.)

Humidity: A high level of humidity can cause

computers to short circuit, resulting in the loss of data and damage to hardware.

Components to rust. For optimal performance, the relative

humidity of the computer room should be above 20 percent and below the dew point.

Environments that require high reliability should have a humidity alarm.



Water Damage: Modern computer systems contain a cut-off

device that is triggered if sprinklers turn on. If a computer suffers water damage, make

sure it is completely dry before restoring the power.

Storage devices and printouts can be damaged or destroyed by water.

Water damage may also occur from flooding or broken pipes.



Magnetic Fields and Static Electricity:

A single spark from static electricity can damage the internal electronics of a computer.

Grounding prevents damaging a computer with a static electrical spark.

Computer rooms should have tile floors and antistatic carpet to reduce static electricity.

Hard drives are sensitive to magnetic fields. Do not store magnets directly on a computer.



Physical Damage: Prevent damage to desktop computers by arranging

equipment so it is stable and cannot fall or be knocked over.

Notebook computers are more prone to physical wear and tear because they are portable.

Most portable systems are insulated with shock absorbing material.

Transport devices with care, such as in padded cases.



Poor Maintenance: One of the best ways to cut down on

computer repair is through preventive maintenance.

Follow a monthly maintenance schedule to keep computer devices in good working order.


Protecting Computers from Power Loss and Fluctuation An unexpected power outage can wipe out

any data that has not been properly saved. Secure electric cords so that they cannot be

disconnected accidentally. Protect computers from power

spikes with a surge suppressor.


Protecting Computers from Power Loss and Fluctuation An uninterruptible power supply (UPS) can

prevent data loss due to power outages. A UPS contains a battery that temporarily

provides power if the normal current is interrupted.


Identifying Common Computer Hardware Problems Computer equipment and stored data are subject to

computer hardware issues. “Crashed” hard drive-caused by software

corruption or hardware defects. Damaged media Printer and monitor problems Loss of network or Internet connectivity General failure

You can solve many problems on your own, while others may require a professional.


Identifying Common Computer Hardware Problems (continued) Crashed Hard Drive: Hard drives can stop working if they become

overheated, are dropped or shaken, become worn out, or are infected with a virus.

To evaluate the condition of the drive: Use a boot disk to determine if the drive is

readable. Use diagnostic and data recovery programs to

locate and recover bad sectors. Use a data recovery service.


Identifying Common Computer Hardware Problems (continued) Damaged Media: Hard drives and other media eventually fail. In many instances, you can recover data.

First, move the damaged media to a secure environment.

Second, inspect or test the media to determine what type of damage has occurred. The type of damage determines the type of recovery method to use.

Another option is to locate a disaster data recovery company to recover data from the computer.


Identifying Common Computer Hardware Problems (continued) Printer Problems: Paper jams stop

printers from printing a file.

Using the wrong paper or using wrinkled or torn paper can cause a paper jam.

Always pull the paper in the direction of the paper path.


Identifying Common Computer Hardware Problems (continued) Printer Problems (continued): If ink or toner comes off the paper when

touched, the fuser assembly might be damaged or need to be replaced; the toner cartridge could be defective; or some toner may have spilled into the printer.

If the printed image is faded, the toner might be low, the print density set too low, or economy mode printing is turned on.


Identifying Common Computer Hardware Problems (continued) Display Problems: The hardware of a display consists of

the monitor and the video card. To troubleshoot a display problem:

Check that the power cord is plugged in and the monitor cable is connected to the computer.

Verify that the monitor is turned on and settings are correct.

Update the video driver.


Identifying Common Computer Hardware Problems (continued) Inoperable Hardware Devices: When a hardware device does not work, it could be a

software problem, an electrical problem, or a mechanical problem.

A small program called a driver instructs the operating system on how to operate specific hardware.

Other causes are incorrect installation of the software or hardware failure.


Identifying Common Computer Hardware Problems (continued) Loss of Network or Internet

Connectivity: Common causes of connectivity problems:

The network provider’s system is not working properly.

Network adapters and switch ports do not match.

The network adapter is incompatible with the motherboard or other hardware components.



Connectivity (continued): Troubleshooting options:

Use the DOS ping command to test connectivity and isolate hardware problems and mismatched configurations.


Identifying Common Computer Hardware Problems (continued)

Loss of Network or Internet Connectivity (continued):



Connectivity (continued): Verify that other computers on the same

network and those plugged into the same switch are also experiencing network connectivity problems.

Restart the router. Check the computer’s network card or

board and verify it is using appropriate settings as indicated by the manufacturer.



Connectivity (continued): Try another network cable. If you are using a wireless router within

a home, beware of signal interference from other home appliances.

Assignments







References

Computer Literacy BASICS: A Comprehensive Guide to IC3, 4th Edition, Morrison / Wells

Documents

Computers and Computer Systems