Fundamentals of computing

Prof. Erwin M. Globio, MSIT

Senior IT Lecturer

Far Eastern University

“Technology makes people evil

or

People makes technology Evil”

Basic concept and principles

of

Computer Technology

INTRO to Computers

and

Applications

Computer Fundamentals

Learning Objective:

At this end of this Lesson the students can be

able to:

Define concisely what is computer.

Identify the basic functions of computer.

Discuss the evolution of computer.

Discuss the different generation of computer.

Classify and differentiate computer types.

Definition

Is an electronic device that:

5 5 + 2

+ 2

5 + 2 = 7 5 + 2 = 7

Computer: Basic Function

A device that:

1. accepts input input – whatever is put into the computer system.

ex. words, symbols, numbers, pictures, audio signal,

instructions from a computer program.

needs an input device

2. process data data – refers to symbols that represent facts, objects, and

ideas.

process – a way in which a computer manipulates data

this process is controlled by a computer program.

processing takes place in a CPU (brain of computer)

Computer

A device that:

3. stores data

Types of Data Storage 1. Memory – (volatile)

ex. memory card, CMOS

2. Storage Device –(non-volatile)

ex. hard disk, floppy disk, usb flash disk, CD‟s etc.,

3. Why is it important for a computer to have a data storage?

4. produces output output – is the results produced by a computer.

ex. reports, documents, music, pictures, videos, etc.,

needs output devices

Evolution

of

Computer Age

First Generation - 1940-1956: Vacuum Tubes

first computers used vacuum tubes for circuitry, and were often enormous, taking up entire rooms

Magnetic drums as primary storage device Uses machine languages for instr. Input punched cards and paper tape output printouts.

Examples of First Generation Computers

UNIVAC – the first commercial computer delivered to a business client.

First seen….

ENIAC – the first computer used for scientific studies.

EDVAC – the first computer to hold both stored program as well as data

“BUG” Literally

Second Generation - 1956-1963: Transistors

Transistors replaced vacuum tubes

smaller, faster, cheaper, more energy-efficient and more reliable.

Computers could handle an enormous amount of data.

used in business, universities, and government from companies.

Third Generation - 1964-1971: Integrated Circuits

Drastically increased the speed and efficiency of computers.

Uses keyboards and monitors and interfaced with an operating system.

Computers been able to run different application program.

Fourth Generation - 1971-Present: Microprocessors

Microprocessor or processor is an integrated circuit designed to process instructions.

CPU is the most important element of a computer system

Assignment

1. Search the internet for the name of the first

UNIVAC, ENIAC and EDVAC created.

2. Search for the first computer program developed

for commercial use.

3. Search for different brands of processor and

compare the price of the processors with the

same specification. (example 2.4 GHz)

4. Search for significant contributions of the “Age of

Connectivity” – 1991 to present. Ex: WI-FI

Capabilities and Scalability

of

Computer

7/27/2012 17

Capabilities of Computer

Capabilities of the computer is defined by its hardware and the software.

Capability of computer is endless and limitless we cannot put boundary to its ability.

Qualities that defines computer capability:

1. Speed

2. Repetitiveness

3. Accuracy

4. Logic operation

5. Store and recall operation

6. Self checking

7. Self operation

7/27/2012 18

Scalability of Computer

Scalability is the ability of the system to improve its performance with the additional hardware, proportional to the additional load.

Dimension of Scalability:

Load scalability:

The ability of a machine to adjust its operation to accommodate changing load.

Geographic scalability:

The ability to maintain performance when there geographic growth.

Functional scalability:

The ability to enhance the system by adding new functionality at minimal effort.

7/27/2012 19

General Applications of Computer

Scientific Research Ex. Cloning, weather forecasting, etc..

Business / Commerce Ex. Banking, online shopping, etc..

Entertainment Ex. Movie effects, gaming, etc..

Education / Information Gateway Ex. World wide web, e-learning, etc..

Connectivity/Communication Ex. Email, web conferencing, blue tooth etc..

Aviation Air Traffic Control, Satellite, etc..

Military Operations Ex. Nuclear weapon, GPS (Global Positioning System), etc..

Programming VBasic, Java, Perl, C++, Delphi, etc..

Artificial Intelligence Robotics, Speech Recognition, etc..

7/27/2012 20

CLASSIFICATION OF

COMPUTER

Classification of Computer

How do we classify computer? 1. Technology

2. Function

3. Physical Size

4. Performance

5. Cost

Computer Categories

1. Mainframe

2. Minicomputer

3. Microcomputer

4. Supercomputer

5. Server

Mainframe

Large, fast and expensive

Centralized storage, processing, distribution, and management of large amount of data.

Reliable and secured.

used by businesses and government.

Mainframe usually comes in 3 units overall operations

handles communication with all users.

finding data requested.

IBM System/360 (S/360)

speed from 0.034 MIPS to 1.700 MIPS

designed to cover the full range of applications, from small to large, both commercial and scientific.

The design is considered by many to be one of the most successful computers in history.

Minicomputer

minicomputer is a system capable of supporting from 4 to

about 200 users simultaneously

smaller, less expensive, and less powerful machines

Perform -> all terminals; business applications

Still existing?

The PDP-8 (1960’s)

the first successful

commercial minicomputer

built with discrete

transistors

Built 60‟s – distribute ‟65

Digital Equipment

Corporation (DEC)

Microcomputers

general-purpose computer useful for individuals, and which is intended to be operated directly by an end user

Also called personal computers, PC ex. desktop, notebook, laptops, PDA

ALTAIR 8800

microcomputer design

from 1975,

based on the Intel

8080 CPU

sold thousands in the

first month.

recognized as the

spark that led to the

personal computer

revolution: computer

bus designed.

Apple II

1977 - one of the first highly successful mass produced microcomputer

among the first home computers on the market, and became one of the most recognizable and successful.

Sold between 5 and 6 million until 1993

Supercomputers

Fastest and most expensive (1M – 100M)

“Compute-intensive” tasks Molecular modelling

Code breaking

Weather prediction

physical simulations

Speed -> Complex processing Movement of thousands of particles in a tornado

Creating realistic animation

Illiac IV

one of the most

infamous

supercomputers ever

built.

256 processors –

parallel processing

The Cray 1

In 1975 the 80 MHz

Cray-1 was

announced.

designed by a team

including Seymour

Cray for Cray

Research.

design to use

integrated circuits

(ICs)

IBM Roadrunner

world's fastest computer

US$133-million

U.S (DoE) National Nuclear Security Administration.

development since 2002, and went online in 2006.

Feb 2009 – starts development of “Sequia” – 20 petaflops

Server

A special type of computer that is configure to “serve” the computers on a network.

store and distribute data and/or allow clients to exchange files or access a centralized resources.

can be personal computer, a mainframe or a supercomputer.

Rear View Server

Compare and Contrast

Components of A Computer

System

Learning Objective:

At the end of this lesson, the student should be

able to:

Identify the different components of the computer

system.

Discuss the role and importance of each

component in the computer system.

Differentiate input devices from output devices.

Enumerate common input and output devices.

Define software and discuss its importance in the

system.

Enumerate the different types of software and their

functions.

Hardware

System Unit

Motherboard

Processor

Memory

Power Supply

Devices

Input

Output

Communication

Components of a Computer System

Hardware

Software

End User

Physical Components of the

Computer System

System Unit Components

Learning Objective

At the end of this lesson, the students should be able to:

Identify the components of the System Unit Enumerate the components of the motherboard Explain the function of the processor: the Control Unit, Arithmetic and Logic unit. List and briefly explain the various types of memory. Explain the function of buses and list different types of buses. Explain the various types of ports and connectors. Discuss the functions of expansion slots and adapter cards. Differentiate internal and external bays. Explain the function of power supply. Define ‘bit’ and describe how a series of bits are used to represent data.

Next: Definition of System Unit

The System Unit

the main body of a computer.

Consist of:

motherboard

cooling fans,

internal disk drives

memory modules

expansion cards

power supply

Next: System Unit w/ labeled parts

The System Unit

Next: Rear view

Rear View of the system unit

Next: System Unit for portable

System Unit for Laptops and PDA

keyboard and

pointing device

are on top of the

system

display is part

of the unit

Next: Motherboard

The Motherboard

Also known as the system board.

main circuit board of the system unit.

Components attached to

the motherboard processor

memory

buses

system clock

expansion slots and adapter cards

ports

Next: Function of motherboard

Function of the Motherboard

provides means of communication between processor and memory.

controls the flow of information through all the components. bus is a subsystem that transfers data between computer

components inside a computer or between computers.

Next: Function in figure

PCI Express bus card slots

(from top to bottom: x4, x16, x1

and x16), compared to a

traditional 32-bit PCI bus card

slot (bottom).

bus provides

means of

transportation

bus stops are the

memory, the

processor and other

peripheral devices

bus carries data and

instruction from one

stop to another and

drop them off as

these stops

Next: Old Motherboard

Old Motherboard

An old IBM 8088

motherboard

Specifications

Processor Intel 8088

Speed 4.77 MHz

RAM 16K-640K

ROM Unknown

Storage

Cassette Tape,

optionally 5.25"

floppy drives, hard disks

Expansion 5 expansion slots

Bus Industry Standard Architecture (ISA)

Video

Initially CGA

(320x200x16

color, 640x200x2

color) or

monochrome (80x25 text only))

I/O Parallel, Serial

Next: Modern Mboard

Modern motherboards include, at a

minimum:

sockets (or slots) in which one or more microprocessors are installed

memory slots into which the system's main memory is installed

a chipset which forms an interface between the CPU's front-side bus, main memory, and peripheral buses

non-volatile memory chips containing the system's firmware or BIOS

a clock generator which produces the system clock signal to synchronize the various components

slots for expansion cards

power connectors flickers, which distribute electric power to the CPU, chipset, main memory, and expansion cards.[

Next: Figure

Modern For Motherboard

Next: Processor

Processor

The Processor

central processing unit (CPU)

brain of the computer

most important and most expensive

various sizes and speed Two basic Components

1. Control Unit

2. Arithmetic and Logic Unit (ALU)

Functions of the processor 1. execute instructions

instructions from program

2. process data

Next: Device communication

How device communicates with

processor to complete a task

input devices

output devices

Storage device

Processor

data

instruction

data

information

instruction

data

information

information

Next: Control unit

The Control Unit

components of the processor that manages all of the computer resources. control and directs the flow of data through the processor and to and from

other devices.

interprets the instructions for a program and executes necessary actions to carry out the instruction.

Next: ALU

The Arithmetic And Logic Unit

performs arithmetic related operations,

comparison operations and logical operations.

Functions of Arithmetic Logic Unit (ALU)

Arithmetic

addition, subtraction, multiplication, division

Comparison

equal to, greater than, less than, greater or equal to, lesser

or equal to

Logical

AND, OR, NOT

Next: Machine cycle

The Machine Cycle

The repetition of series of steps for every

instruction the processor executes.

Machine Cycle

Instruction Cycle Execution Cycle

Fetching Decoding Executing Storing

Retrieves

(fetches) a

command/data

from the memory

Translates

(decodes)

instructions into

signals the

computer can

understand

Carries out

(execute) the

commands listed

in the instructions

Writes (stores)

results to

memory.

Next: performance

factor

Performance Factors of Processor

A. Registers small, high-speed temporary storage located in the

ALU. The amount of data which the computer can work with

at any given time is referred to as the word size.

word size is measured in bit a 64-bit processor can process data twice as much as 32-

bit.

Functions of Registers store the locations where instructions were fetched from.

store an instruction while the instruction is being decoded by the control unit.

store data while the ALU computes the data.

store the results of calculations

Next: System clock

Performance Factors of

Processor

B. System Clock

timer that times the processing operations of the

computer.

sets the pace for executing instructions.

Clock cycle

Measured in hertz, cycles per second.

2.4 GHz means ~ 2.4 billion cycles per second.

processor can be able to execute instruction in

every cycle.

the speed of processor to carry out an instructions

depends on the speed of the system clock.

Next: Cache Memory

Performance Factors of

Processor

C. Cache Memory (“cash”)

sometimes called “RAM cache” or “cache

memory” – measured in KB or MB

Special high-speed memory that allows a

microprocessor to access data rapidly than from

memory located elsewhere on the motherboard.

Level1 cache(L1) – built into the processor chip.

Level2 cache(L2) – located on a separate chip and

takes little more time to get data to the processor.

used in motherboard, but was later built into the CPU

Usually tied with the processor brand and model –

non-upgradeable.

Next: Method of processing

Performance Factors of Processor

D. Method of processing

Processors are basically designed to process one instruction at a time, this refers to as Serial Processing. process must complete all of the steps of machine cycle before it

begins to process a new instruction.

Pipelining a technology that allows a processor to begin a new instruction

before it completes the previous one.

Parallel Processing

new technology for new generation processors

allows simultaneous multi-processing. pizza analogy

Next: Fast processor

Fast Processor

Processor

Clock

Speed

(GHz)

Price

QPI

Speed

(GT/sec)

Cache

Memory

Speed

Support

TDP Processor

Generation

Intel® Core™ i7-

965 Extreme

Edition

3.20 $999 6.4

8 MB DDR3-

1066

130

W

New Intel® Core™

Microarchitecture

(Nehalem) 45nm Intel® Core™ i7-

940 2.93 $562 4.8

Intel® Core™ i7-

920 2.66 $284 4.8

•

Primary Data Storage

Memory

Memory

Memory is an electronic components in your

computer that stores:

instructions waiting to be executed

data needed by the instructions and

the results of processed data.

How does computer finds requested data?

Memory are virtual

location inside your

computer

A1 B1 C1 D1

A2 B2 C2 D2

A3 B3 C3 D3

#9 Wilson St

each location has

unique

identification called

address

01101100 10001011

01100111 10001100

the content of each

memory address is

called bytes

Next: Memory Arcihtecture

common memory architecture within

most modern computers.

Next: Units of memory

Memory And Storage Size

Term Abbreviation Approximate

Size

Exact Amount Approximat

e Pages of

Text

Kilobyte KB or K 1 thousand

bytes

1,024 bytes ½

Megabyt

e

MB 1 million bytes 1,048,576 bytes 500

Gigabyte GB 1 billion bytes 1,073,741,824

bytes

500,000

Terabyte TB 1 trillion bytes 1,099,511,627,776

bytes

500,000,000

stated in terms of the number of

bytes available for storage in the chip

or device

Next: Types

Types of Memory

Volatile

Temporary memory

Contents are lost when the

computer is turned off.

Common Type

RAM

Random Access Memory

Non-volatile

Permanent memory

Contents can be preserve

even if the computer is off.

Common Types

ROM

Read-only memory

Flash memory

CMOS

Next: RAM

RAM

Main memory or primary storage

RAM is considered "random access"

because you can access any

memory cell directly

holds operating system files,

program files and data files needed

for processing.

can handle multiple programs

simultaneously.

Ram is volatile.

The process of copying items from RAM

to a storage device is known as saving.

What are the different types of ram

and which one is on your pc?

Types of Ram Chips

DRAM – Dynamic RAM

Needs to refresh thousands of times to keep contents

Slower

Less Expensive than SRAM

Used for large amount of temporary storage.

SRAM – Static RAM

Doesn‟t need to refresh

Faster

More expensive

Used to create the CPU‟s

cache memory.

Next: DRAM

How Dynamic RAM Works

DRAM mainly consists of millions capacitors

and transistors

Transistor acts as a switch that control the

flow of electrons to the capacitors.

To store 1, the bucket is filled, to store 0 the

bucket is emptied.

0 and 1 represent bit, the smaller unit of

information in a computer.

The problem with the capacitor's bucket is

that it has a leak.

In a matter of a few milliseconds a full bucket

becomes empty.

Therefore, for dynamic memory to work,

either the CPU or the memory controller has

to come along and recharge all of the

capacitors holding a 1 before they discharge.

How Static RAM works

Static RAM uses flip-flop technology that holds each bit of memory permanently while there is electric current.

Using flip-flop for a memory cell doesn‟t require refreshing but requires a lot of wiring This makes static RAM significantly faster than dynamic RAM but

takes up a lot more space on a chip than a dynamic memory cell.

Therefore, you get less memory per chip, and that makes static RAM a lot more expensive.

used to create the CPU's speed-sensitive cache, while dynamic RAM forms the larger system RAM space

Next: Types of RAM

Common Types of RAM

SRAM: Does not need refreshing, but

requires several wiring connected to the transistors, used primarily for cache.

DRAM: type of memory that requires constant

refreshing.

SDRAM: Synchronous dynamic random access

memory

faster than DRAM because they are synchronous with the system clock.

the most common form in desktops today.

DDR SDRAM: Double data rate synchronous

dynamic RAM is just like SDRAM except that is has higher bandwidth, meaning greater speed.

RDRAM: Rambus dynamic random access memory use of a special high-speed data bus

called the Rambus channel that makes memory chips work in parallel to achieve a data rate of 600 MHz, or 1,600 MBps.

Speed versus heat

Next: Memory module

Memory Modules

SIMM, which stands for

single in-line memory

module.

30-pin connector, 3.5 x .75

inches in size – max 32 MB

In most computers, you had to

install SIMMs in pairs of equal

capacity and speed.

This is because the width of

the bus is more than a single

SIMM.

Later 4.25 x 1 – max 256 MB

Next: DIMM and RIMM

Memory Modules

DIMM, which stands for dual in-line memory module. 168-pin or 184-pin connector, 5.4 x 1

inch in size

8 MB to 1 GB

RIMM, which stands for Rambus in-line memory module comparable in size and pin

configuration to DIMM but uses a special memory bus to greatly increase speed

800 MHz, or 1,600 MBps data rate

Can we use it for portable pc?

Next: SODIMM

Memory Modules

SODIMM, which stands for

small outline dual in-line

memory module

144 or 200 pins, 2 x 1 inch

16 MB to 1 GB per module.

used in notebooks and

laptops.

some notebook uses smaller

DIMMs, known as

MicroDIMM.

Next: Most common memory type

Other Memory Modules

Top L-R, DDR2 with heat-spreader, DDR2 without heat-spreader, Laptop

DDR2, DDR, Laptop DDR

Next: Access Time

Access Time

The amount of time it takes for the processor to read data, instructions, and information from memory. usually expressed in ns (nanoseconds).

Newer memory have speed expressed in MHz.

RAM TYPE RAM Speed

EDO 16 MHz (60 ns)

SDRAM 66 MHz (15ns) – 133 MHz (7.5ns)

RDRAM 600 MHz (1.7 ns) – 800 MHz (1.3 ns)

Next: How much do we need?

How much RAM do you need?

The amount of RAM for your system varies

depending on several factors.

1. The Operating System you‟re putting in to your

computer. Windows 95/98, min of 32 MB, 64 MB is recommended.

Windows NT/2000 min 64 MB, 128 MB is recommended.

Windows XP, min 128MB, 256MB is recommended.

Windows Vista, min 256, 512 is recommended

2. How you‟re going to use your pc.

High-end user vs. basic user.

Does adding more RAM makes your computer

faster?

Next: Other Primary Storage

ROM

Read-only memory

also known as firmware, is an

integrated circuit programmed

with specific data when it is

manufactured.

ROM chips are used not only in

computers, but in most other

electronic items as well.

Next: Characteristics of ROM

Characteristics of ROM

Data stored in these chips is nonvolatile -- it is not lost when power is removed.

Data stored in these chips is either unchangeable or requires a special operation to change, unlike RAM.

Ideal memory for storing the BIOS Basic Input Output System

Next: Types of ROM

Types of ROM

ROM

ROM uses a diode to its control circuit.

ROM chip works necessitates the programming of

perfect and complete data when the chip is created.

ROM are disposable.

They use very little power, are extremely reliable and,

in the case of most small electronic devices, contain

all the necessary programming to control the device.

Next: PROM

Types of ROM

PROM programmable read-only memory

Blank chips that can be coded by anyone with a special tool called a programmer.

Mainly consists of wires and fuses that needs to be burn to embed program. This process is known as burning the PROM.

PROMs can only be programmed once.

Blank PROMs are inexpensive and are great for prototyping the data for a ROM before committing to the costly ROM fabrication process.

Next: EPROM

Types of ROM

EPROM

Erasable programmable read-only

memory

Can be rewritable many times but needs

to be erased.

Erasing an EPROM requires a special

tool that emits a certain frequency of

ultraviolet (UV) light

Erasing requires removing into the

device and exposure under UV light for

several minutes.

Next: EEPROM

Types of ROM

EEPROM Electrically erasable programmable read-only memory.

The chip does not have to removed to be rewritten.

The entire chip does not have to be completely erased to change a specific portion of it.

Changing the contents does not require additional dedicated equipment.

Instead of using UV light, you can return the electrons in the cells of an EEPROM to normal with the localized application of an electric field to each cell.

The process of rewriting is versatile but slow.

Next: FLASH

Types of ROM

Flash memory

type of EEPROM that uses in-circuit wiring to

erase by applying an electrical field to the entire

chip or to predetermined sections of the chip called

blocks.

Flash memory works much faster than traditional

EEPROMs because it writes data in chunks,

usually 512 bytes in size, instead of 1 byte at a

time.

Next: FLASH

FLASH

A portable storage devices that use a type of electronic memory called flash memory. also known as a solid state storage device, meaning there are no moving

parts instead purely electronic.

Here are a few examples of flash memory: Your computer's BIOS chip

CompactFlash (most often found in digital cameras)

SmartMedia (most often found in digital cameras)

Memory Stick (most often found in digital cameras)

PCMCIA Type I and Type II memory cards (used as solid-state disks in laptops)

Memory cards for video game consoles

Next: Flash vs HDisk

Advantages of using flash memory

over hard disk

There are a few reasons to use flash memory instead of a hard disk: It has no moving parts, so it's

noiseless.

It allows faster access.

It's smaller in size and lighter.

Why can‟t we just use flash memory for everything?

Next: CMOS

CMOS

Complementary Metal Oxide Semiconductor."

Technology used in some ROM chips, flash memory chips and other types of memory. run efficiently and fast but using up very little power.

You may also find CMOS memory in your computer, which holds the date and time and other basic system settings.

The low power consumption of CMOS allows the memory to be powered by a simple Lithium battery for many years.

Computer

Buses

Computer Bus

a subsystem that transfers data between

computer components inside a computer or

between computers.

allows the travel of bits from one destination to

another

bit is the smallest unit of data that computer can

process and store.

bit is represented by 0 and 1

0 and 1 are typically referred to as the machine

language.

8 bits = 1 byte

Next: Buses Diagram

Computer buses

•FSB or frontside bus

is a physical

connection that

actually connects the

processor to most of

the other

components.

• usually operates at

400-MHz, with newer

systems running at

800-MHz.

• The backside bus is a

separate connection

between the processor

and the Level 2 cache.

• This bus operates at

a faster, usually at the

same speed as the

processor, so all that

caching works as

efficiently as possible. •PCI bus

• These slower buses

connect to the system

bus through a bridge,

which is a part of the

computer's chipset

and acts as a traffic

cop, integrating the

data from the other

buses to the system

bus. Next: Types

Types of Buses

Internal Buses also known as the system bus

or the local bus.

reside on the motherboard and connects the processor to other devices on the main circuit board. Data bus – used to send and

receive data between devices

Address bus – connects processor and ram, responsible for addressing of requests.

External Buses

also known as expansion

bus.

connect external devices

into the main circuit

board.

used by keyboard, mouse,

monitor and printer

Next: Factors

Factors That Affects the Speed of

data transfer

Bus Width

The number of bits that the computer can transmit

at one time.

32-bit bus can transmits 32 bits (4 bytes)

64-bit bus can transmits 64 bits (8 bytes)

Bus Speed

The speed that the bus could transfer data from

one device to another.

Measured in MegaHertz (MHz)

current bus speed is 400 MHz – 800 Mhz newer

Next: Standard Bus

Standards for Different Buses

1. ISA – Industry Standard Architectural Bus

2. VESA/VL Bus – Video Electronics Standard Association Local Bus

3. PCI – Peripheral Component Interconnect Bus

4. AGP – Accelerated Graphic Port Bus

5. PCI Express– Peripheral Component Interconnect Express Bus

6. USB – Universal Serial Bus

7. IEEE 1394 – Firewire

8. PC Card

9. Express Card

ISA

computer bus standard for IBM compatible

computers.

still used to connect slower devices, such as

modems and input devices to the processor.

Later on replaced by 32-bit EISA

Five 16-bit and one 8-bit ISA slots on a motherboard

VESA

Video Electronic Standard Association Local Bus

A VLB slot itself was an extension of an existing

ISA slot. Indeed, either a VLB or an ISA card could

be plugged into a VLB slot.

Bus width 32 bits

Compatible with 8 bit ISA, 16 bit ISA, VLB

PCI

Peripheral Component Interconnect

The PCI Local Bus developed by Intel is common in modern PCs, where it has displaced ISA and VESA Local Bus as the standard expansion bus, and it also appears in many other computer types

Offer past transfer speeds and a 32-bit or 64-bit data bus.

Typically house a graphics card, sound card, video card, video capture card, modem, or network interface card.

AGP

Accelerated Graphics Port a high-speed point-to-point channel for attaching a video card,

primarily to assist in the acceleration of 3D computer graphics.

The primary advantage of AGP over PCI is that it provides a dedicated pathway between the slot and the processor rather than sharing the PCI bus. Number of devices: 1 device/slot Capacity up to 2133 MB/s

PCI Express

a computer expansion card standard designed to replace the older PCI and AGP standards.

Introduced by Intel in 2004, PCIe is the latest standard for expansion cards that is available on mainstream personal computers.

A PCI Express x16 slot

A PCI Express x1 slot

Specs for each generation per lane

Clock

speed

Transfer

rate Data rate

1.x 1.25 GHz 2.5 GT/s 250 MB/s

2.0 2.5 GHz 5 GT/s 500 MB/s

3.0 4 GHz 8 GT/s 1 GB/s

Specs for each generation per lane

USB

Universal Serial Bus (USB)

USB was designed to allow many peripherals to be connected using a single standardized interface socket and to improve plug and play capabilities by allowing hot swapping hot swapping allows devices to be connected and disconnected without rebooting the computer

or turning off the device.

USB can connect computer peripherals such as mice, keyboards, PDAs, gamepads and joysticks, scanners, digital cameras, printers, personal media players, flash drives, and external hard drives. For many of those devices, USB has become the standard connection method.

Supports up to 127 devices connected in a daisy chain

IEEE 1394 - FIREWIRE

The IEEE 1394 interface is a serial bus interface standard for high-speed communications and real-time data transfer, frequently used by personal computers, as well as in digital audio, digital video, automotive, and aeronautics applications.

It remains the primary transfer mechanism for almost all high end professional audio and video equipment.

Used by Mac but now available to IBM-compatible pc.

PC Card

PC Card (originally PCMCIA Card) PCMCIA - Personal Computer Memory Card International

Association

form factor of a peripheral interface designed for laptop computers.

PC Card was originally designed for computer storage expansion, but later on become the form for attaching network cards, modems, and hard disks. Allows attach/detach without affecting the computer.

Express Card

ExpressCard is a hardware standard expansion slot, commonly found in laptop computers, replacing older and bigger PC Card slots.

Uses of E-Card audio/video adapters,

storage modules

storage adapters

wireless adapters

TV tuners

various memory card readers.

Some popular ExpressCard®

applications include TV Tuners,

eSATA, FireWire, wireless WAN and

wireless networking.

Expansion

Ports

Expansion Port

Expansion Port

Any connector that passes data in and out of a

computer or peripheral device.

could be housed on an expansion card.

could be built into the system unit.

How to figure out which connector for which port?

Next: Port Diagram

Typical System Unit Ports

Next: USB

Universal Serial Bus (USB)

A serial bus standard to connect devices to a host computer.

sends data over single data line. 1.0 – speed from 1.5Mbit/s to 120Mbit/s

2.0 – speed 480 Mbit/s

SB is a standard port designed to improve plug and play capabilities by allowing hot swapping. hot swapping allows devices to be

connected and disconnected without rebooting the computer or turning off the device.

Next: Firewire

IEEE 1394 interface (FireWire)

A serial bus interface

standard for high-speed

communications and

real-time data transfer.

Since 2003 many

computers intended for

home or professional

audio/video use have

built-in FireWire.

Next: Ethernet

Ethernet Port

Ethernet is a family of

frame-based computer

networking technologies

for local area networks

(LANs).

It defines a number of

wiring and signaling

standards for the

Physical Layer of the

OSI networking model.

Next: Serial

Serial Port

A serial communication physical interface through which information transfers in or out one bit at a time (contrast parallel port).

Sends data over a single data line one bit at a time at speeds of 56 kbps.

Use to connect earlier mouse or modem.

Next: Parallel

Parallel Port

A parallel port is a type of interface for connecting various peripherals. It is also known as a printer port.

Sends data simultaneously over 8 data lines at speeds o 12,000 Mbit/s.

Printer, external CD-ROM drive, Zip drive, external hard disk.

Next: PS/2

PS/2 Connector

The PS/2 connector is used for

connecting some keyboards and mice to a PC compatible computer system.

Its name comes from the IBM Personal System/2 series of personal computers,

Replaced the older "serial mouse" and keyboard connector (but not interchangeable)

Serial data at 10 to 16 kHz

Next: VGA

VGA Port

Video Graphics Array (VGA) refers specifically to the display hardware first introduced with the IBM PS/2 line of computers in 1987

also known as RGB connector, D-sub 15, mini sub D15 and mini D15

Used to connect an analog monitor to the system unit.

Next: DVI

DVI Port

The Digital Visual Interface (DVI)

is a video interface standard designed to provide very high visual quality on digital display devices such as flat panel LCD computer displays and digital projectors.

It is partially compatible with the High-Definition Multimedia Interface (HDMI) standard in digital mode (DVI-D), and VGA in analog mode (DVI-A).

Next: SCSI

SCSI - (pronounced scuzzy),

Small Computer System Interface

A set of standards for physically connecting and transferring data between computers and peripheral devices.

sends data simultaneously over 8 or 16 lines at speeds between 40Mbit/s and 640Mbit/s.

Supports up to 16 devices.

SCSI is most commonly used for hard disks and tape drives, but it can connect a wide range of other devices, including scanners and CD drives.

Drive Bays

Computer Drive Bays

Refers to a location in a system unit where a hard or floppy disk drive, CD-ROM drive or tape drive can be installed.

A drive bay is a standard-sized area for adding hardware to a computer. Thus, the number of drive bays in a computer determines

how many mass storage devices can be internally installed.

Commonly used to store disk drives, although they can also be used for front-end USB ports, I/O bays, card readers, fans, tool storage, and other uses.

Next: Type: Internal

Internal Bay

Also referred to as

hidden bays

There is no physical

outside access.

Cannot be used for

removable media,

such as floppy drives,

and USB.

Next: Type External

External Bay

Also referred to as exposed bay

There is a need for physical outside access.

Floppy, drives and CD-ROMs slide into external bays and can be seen (and accessed) from the front of your system case.

Next: Pow Supp

Power supply unit (computer)

A power supply unit (PSU) is the component that supplies power to the other components in a computer.

Designed to convert (AC) electric power to usable low-voltage DC power for the internal components of the computer.

Some have power selector while some have auto power detection.

Next: Connector

Typical Connectors for the PS

PC Main power connector is the connector that goes to the motherboard to provide it with power. The connector has 20 or 24 pins.

4-pin Peripheral power connectors (usually called Molex for its manufacturer) that goes to the various disk drives of the computer.

4-pin Berg power connectors (usually called Mini-connector or "mini-Molex"): This is one of the smallest connectors that supplies the floppy drive with power.

Auxiliary power connectors: There are several types of auxiliary connectors designed to provide additional power if it is needed.

Next: Digital Rep

COMPUTER SOFTWARE

Learning Objective

After this lesson, the students should be able to:

Define and differentiate computer program and

computer software.

Enumerate different type of software.

Differentiate System Software and Application

Software

Define and enumerate the different types of

System Software

Define and enumerate the different types of

Application Software

DEFINITION

COMPUTER PROGRAM

Is a set of detailed, step-by-step instructions that tells a

computer how to solve a problem or carry out a task.

COMPUTER SOFTWARE

The instructions and associated data, stored in

electronic format, that direct the computer to

accomplish the task.

Differentiate Software, Program and Application.

CLASSIFICATION of SOFTWARE

Software are classified based on how they could

be used.

1. Copyrighted Software

2. Licensed Software

3. Shareware

4. Freeware

Copyrighted Software

software that is exclusive to the owner or the developer.

copyright - form of legal protection that grants the copyright

exclusive rights to copy the software, to distribute or sell it,

and modify it.

I purchased a software, can I copy it for my friends?

Exclusive Rights in Copyrighted Works

1. Only the copyright owner can reproduce, sell, or distribute the

copyrighted software.

2. It is legal to copy the software from the distribution disks to the hard disk

of your computer.

3. It is legal to make an extra copy of the software in case the copy you are

using becomes damaged

4. If you give away or sell the software, you cannot legally keep a copy.

5. You cannot legally sell or give away modified or copies of the software

without permission.

Copyrighted SW

Licensed Software

software that is protected by law stating the

constraints and limitation of the use.

software license - legal contract that defines the

ways in which you may use a computer program.

Differentiate copyright and license? license can extend the regulations declared by the

copyright.

shrink wrap license – a license that is usually attached in the plastic wrapper of a disk, CD or DVD software

Licenses for Users

Single-user license

limits the use of the software to only one user at a time

Multiple-user license

- allows more than one person to use a particular

software package

Concurrent-use license

- allows a certain number of copies of the software to be

used at the same time

Site license

- generally allows the software to be used on any and all

computers at a specific location.

What about those software offered over the internet for free?

Sample of Licenses

Shareware

is a copyrighted software marketed under a “try

before you buy” policy.

Freeware

also refers to as public domain software

put in the public domain to be used by any person

without limitations

SOFTWARE

CATEGORIES

System Software

Application Software

System Software

helps the computer carry out its basic operating

tasks.

Classification of System Software

1. Operating systems

2. Utility programs

3. Device Driver

4. Computer Programming Language

5. Communication software.

Operating System

Is essentially the master controller

for all of the activities that takes

place within a computer.

It sets the standards for all the

program and application that will be

used in a computer

Operating Systems

Utility Programs

Designed to augment the operating system by

providing a way for a computer user to control the

allocation and use of hardware resources.

ex.(OS utility) Defragmenter, Diskformatting,

DiskPartitioner, Scandisk etc…

ex.(Optional Utility) Norton PartitionMagic, McAfee

Antivirus, Symantec File Recovery etc..

OS Utility

Optional Utility

The system software that helps the computer control a peripheral device.

Device Driver

Computer Programming Language

Allows a programmer to write a program using English-like instructions.

Communication Software

Allows multiple computer to communicate and share resources

Internet

LAN

WAN

Application Software

helps the human user perform an specific task.

can be generic or be-spoke

Classification of Application Software 1. Document Production

2. Graphic Software

3. Presentation

4. Spreadsheet and Statistical

5. Database

6. Information and Reference

7. Connectivity / Communication

8. Education and Training

9. Multimedia

10.Gaming and Simulation

Document Production Software

group of software specific for writing software documentation, designing a brochure, laying out school newsletter etc

WORD PROCESSING SOFTWARE replaced typewriters for producing documents such as report,

letter, papers and manuscript. ex. MSWORD, Corel WORPERFECT, Lotus WORDPRO

DESKTOP PUBLISHING SOFTWARE takes word processing software one step further by helping

you use graphic design technique to enhance the format and appearance of a document. ex. AdobePageMaker, Corel Ventura Microsoft Publisher

WEB AUTHORING SOFTWARE helps you design and develop customized Web pages that you

can publish electronically on the internet. ex. SoftSquad HotMetal, Macromedia Dreamweaver,

MSFrontpage

Document Production Software

Graphic Software

group of software specific that helps you create, edit, and manipulate images.

PAINT SOFTWARE

sometimes called image editing software, used to draw or

create paintings, sketches and other images

ex. MSPAINT, CORELDRAW etc

PHOTO EDITING SOFTWARE

includes feature specially designed to fix poor quality photos.

ex. PHOTOSHOP, Windows Imaging

3-D GRAPHICS SOFTWARE

helps you create and render three dimensional object.

ex. MAYA, 3D Studio, AutoCAD

Presentation Software group of software that provides all of the tools you need

for combining text, graphics, animations and sounds into a series of electronic slides.

ex. Microsoft Powerpoint, Lotus Freelance Graphics

Spreadsheet and Statistical

Software

SPREADSHEET SOFTWARE

perform calculations based on numbers and formulas that you enter.

ex. MsExcel, Lotus 123

STATISTICAL SOFTWARE

helps you analyze large sets of data to discover relationship and patters.

ex. SPSS, JMP, and DATA DESK

Mathematical Modelling Software

provides tools for solving a wide range of math, science, and engineering problems

ex. MathCAD and MATHEMATICA

Spreadsheet and Statistical

Software

Database Software

provides a flexible way to join and summarize the information in more than one file.

Information Reference Software

software that provides a collection of information and a way

to access that information.

ex. Microsoft‟s Encarta, Britannica, Comptons Encyclopedia

Connectivity / Communication

Software

software that connects your computer to a local computer

network on the internet and provides tools that you can use

to take advantage of the information and communications

they offer.

ex. Yahoo messenger, Eudora Email, Netscape and IE

Education and Training Software

software that helps the user practice new skills.

Multimedia Software

software that transform your computer into video

and audio station.

Games / Simulation Software

computer into a game station for entertainment and

learning purpose.

Activity 3

Assemble your virtual ideal personal computer by browsing different parts comprises of: 1. Display Device

2. System Unit

3. 5 Input Devices (state your personal purpose)

4. 5 Output Devices (state your personal purpose)

5. If you would be installing 10 Software in your assembled computer, what are those? (state your purpose)

6. Create the presentation about your pc.

7. Name the presentation file: Fullname_Act2

Digital Representation

Bits and Bytes

Data Representation

A way of converting letters, sounds, and images

into electrical signals.

Why there is a need for conversion?

A

Next: Why Digital

Why Are Computers Digital

Digital device works with discrete – distinct or

separate data or digits such as 1 and 0.

Analog device works with continuous data.

Digital Technology are relatively simple, dependable

and adaptable technology.

switches have only two states On or Off.

0011 – “off” “off” “on” “on”

0‟s and 1‟ are called the binary digits – “bits”

Next: Num & Data

Representing Numbers and Letters

Numeric data consists of numbers that might be

used in arithmetic

ie., annual income, score in exams, age.

Computers represent numeric data using the

binary number system, also called “base 2”.

Character data is composed of letters, symbols,

and numerals that will not be used in arithmetic

operations.

ie., name, address, gender, status

Next: Rep vid & Snd

Representing Sounds and Video

Computers must digitize colors, notes and instrument sounds into 1‟s and 0‟s. Digitizing is the process of converting colors and

sounds into numbers which can be represented by bits.

How does computer identify which digits are for which file? file header file identification stored along with the file and can be

read by the computer, but never appears in the screen.

Next: Diff b & B

Quantifying Bits and Bytes

Difference between bits and bytes

bit is the smallest unit of data

Byte is equivalent to 8 bits

bit is abbreviated by lowercase b while byte is

represented by uppercase B

bit is used for transmission speed

Byte is used to denote disk capacity.

Data Storage

Next: LO

Lesson Objective:

At the end of this lesson, the students should be able to: Discuss the importance of storage device in the Computer System

Differentiate memory and storage.

Differentiate Logical and Physical storage.

Differentiate the two technologies in storage such as; Magnetic Storage and Optical Storage.

Enumerate different types of magnetic storage devices and discuss their operation, characteristics, and advantages and disadvantages.

Enumerate different types of optical storage devices and discuss their operation, characteristics, and advantages and disadvantages.

List and describe other special purpose storage devices.

Explain enterprise Storage Systems and Data Warehouses.

Next: Storage Perception

Two Storage Perceptions

1. Logical Storage How we think data are stored in our storage

device. ie. Data inside the folder or on the physical devices.

2. Physical Storage Its how data are actually stored in our storage

devices.

It‟s the process being done by the computer and the storage devices.

Next: Diff memory & SD

Memory vs Storage Devices

Memory (volatile) Sometimes called primary storage

A temporary holding place for data and instructions.

More expensive yet faster than other storage devices.

Storage Devices (non-volatile) Sometimes called secondary storage.

An area in the computer where data are permanently stored.

Cheaper than memory chips, has higher storage capacity yet slower data access.

Components Of Data Storage

Storage Media

The physical mediums on which data, information

and instructions are held.

Also known as secondary storage.

Kinds of Medium

1. Floppy Disk

2. Hard Disk

3. Mini Disk

4. CD

5. PC card/Memory card

6. Other storage such smart cards, microfilm, tapes and

other special purpose storage device.

Next: Components of DS

Components Of Data Storage

Storage Device

Piece of hardware that saves (writes) or retrieves

(read) data, information and instructions from

storage media.

Kinds of Devices

1. Floppy Disk Drive

2. Hard Disk Drive

3. Tape Drives

4. CD Drives

Next: Storage Basics

Storage Basics

Writing Is the process of transferring data, information, and

instructions from main memory to the storage medium.

Reading Is the process of transferring data, information, and

instructions from medium to the storage main memory.

Storage capacity The amount of bytes of data, information and

instructions that can be kept by storage medium.

Next: Storage Tech

Storage Technology

1. Magnetic Storage

2. Optical Storage

Magnetic Storage

Stores data by magnetizing microscopic particles

on the disk or tape surface.

Uses read-write head mechanism to store and

retrieve data

Read-write head mechanism in the disk drive

records and writes the magnetized particles that

represent data.

Changing or deleting of data is done by changing

the orientation of particles in the disk surface.

Next: Adv and Diadv

Magnetic Storage

Disadvantages

Susceptible to magnetic fields, dust, mold, smoke

particles, heat & mechanical problem with the

storage device.

Gradually lose their magnetic changes resulting in

loss of data.

Short life span (2 – 20 years)

Advantage

Newer magnetic storage disks have high storage

capacity.

Usually cheaper.(?)

Next: OpticalStorage

Optical Storage

Stores data as microscopic light & dark spots on the disk surface.

Uses laser light and it is possible to see the data using high-powered microscope.

Disadvantages

Several process for writing data

Requires software for writing data

Slower than hard disk

Advantage

Strong damage resistance

Longer life expectance (20 – 100 years)

Next: Factors

Factors for Choosing The Best

Storage Technology

1. Versatility Accessibility of the medium to different device.

2. Durability Susceptibility of the medium

3. Speed Access Time

Average time it takes for a computer to locate data on the medium and read it.

Measures in ms (millisecond) Sequential Access – reads though data from beginning

Random Access – “direct access ability to jump to the requsted data.

Data Transfer Rate Amount of data that a storage device can move from the storage

medium to the computer.

Measured in Bps (Bytes per second)

Factors for Choosing The Best

Storage Technology

4. Capacity

The amount of data that the storage medium

could keep.

Measured in Bytes. (MB, KB, GB, TB)

5. Cost

Amount per megabytes.

Storage Term

Term Abbreviation Approximate Size Exact Amount

Kilobyte KB or K 1 thousand bytes 1,024 bytes

Megabyte MB 1 million bytes 1,048,576 bytes

Gigabyte GB 1 billion bytes 1,073,741,824 bytes

Terabyte TB 1 trillion bytes 1,099,511,627,776 bytes Next: FDisk

Magnetic Storage

Floppy Disk Technology

• Floppy Disk

• Floppy Disk Dive

Floppy Disk

Small removable,

flexible magnetic

platter encased in a

plastic housing.

Made up of of a thin,

circular, flexible mylar

plastic disk with a

magnetic coating.

Also referred to as

floppies or diskettes.

Next: Data Location

Data Location on Floppy Disk

A - track

B – Geometrical Sectors

C – Track sector

D – Clusters

A disk drive track is a circular path on the surface of a disk or diskette.

A sector is a subdivision of a track on a magnetic disk or optical disc. Each sector stores provides space for 512 bytes (for

magnetic disks) or 2048 bytes (for optical discs) of user-accessible data per sector.

A cluster is the smallest logical amount of disk space that can be allocated to hold a file. cluster sizes range from 1 sector (512 B) to 128

sectors (64 KB)

Next: Mech Parts

Parts of Floppy Disks

Shutter Protects the magnetic disk when not in use.

Spring snaps the shutter closed again so no dust or fingerprints

can get onto the magnetic disk.

Magnetic disk This round piece of plastic is coated with magnetized iron

oxide.

Hub The metal center of the magnetic disk. The holes in the

hub fit over spindles inside the computer and hold the disk in place while it spins.

Paper rings glued down to the plastic housing, stay still while the disk

spins and clean the disk, removing microscopic bits of dust.

Write-protect tab When the hole is open, the disk is locked. Your computer

won't allow you to add anything to the disk or erase anything from it.

Plastic flap It functions as a simple spring that pushes the paper ring

tight against the surface of the magnetic disk.

Next: Type of FD

Types of Floppy Disk

3 ½ inch

Larger capacity 1.44MB

HD / DD

5 ¼ inch

Common size before

1987

Capacity – 100K and

1.2MB

No longer available

Next: Care for FD

Protecting Your Floppy Disk

Avoid exposure to heat, cold and magnetic fields.

Avoid exposure to dusts, smoke, or water.

Do not eject the floppy disk until the light on the front of the drive is off and until all files on the floppy disk have been saved and closed.

Always carry disks case or box.

Do not touch the surface of the disk.

Do not use damage disks or disks with faulty shutter to avoid jamming in the drive.

Remember to write protect to avoid accidental erasure of data.

Next: Adv and Disadv

Advantages and Disadvantages

Advantages:

They are very cheap to buy

floppy disc drives are very common.

Disadvantages:

very small storage capacity

Susceptible to a lot of damages.

Slower

The access speed is about 36 KB per second.

Not all modern computers have floppy disk drives.

Next: FDD

Floppy Disk Drive

A device that can read from and write on a floppy disk

Can be external or internal

Most personal computers have a floppy disk drive, in which you insert and remove a floppy disk

Next: Parts of FDD

Parts of a Floppy Disk Dive

Read/Write Heads:

Located on both sides of a diskette used for reading and writing data on the disk.

Spindle Motor: engages the metal hub at the center

of the diskette, spinning it at either 300 or 360 rotations per minute (RPM).

Stepper Motor: move the read/write head assembly to

the proper track position. The read/write head assembly is fastened to the stepper motor shaft.

Circuit Board: Contains all of the electronics to

handle the data read from or written to the diskette.

Next: How FDD Works

Step 6: The

read/write heads

read data from and

write data on the

floppy disk.

Step 6

Step 5: A motor

positions the

read/write heads

over the correct

location on the

recording surface

of the disk.

Step 5

Step 4: A motor

causes the floppy disk

to spin.

Step 4

Step 3: If disk access

is a write instruction,

the circuit board

verifies whether the

disk can be written to

or not.

Step 3

Step 2: When you

initiate a disk

access, the circuit

board on the drive

sends signals to

control movement

of the read/write

heads and the disk.

Step 2

Step 1: When you insert

the floppy disk into the

drive, the shutter moves

to the side to expose the

recording surface on the

disk.

Step 1

Floppy Disks Operation

How does a floppy disk drive work?

Next: Disk Backup

High Capacity Disk

A disk drive that uses disks with capacities of 100 MB and greater

Next: HiFD

HiFD

HiFD™

(High-Capacity

Floppy Disk) drive

Uses a 200 MB

HiFD™ disk

Developed by

Sony Electronics,

Inc.

Next: SuperDisk

SuperDisk

Designed to replace

regular floppies

Can read regular

floppies

Uses a 120 MB or a

250 MB Super Disk

Developed by Imation

Next: ZipDrive

Zip Drive

Uses a Zip® disk that

can store 100 MB or

250 MB of data

Developed by Iomega

Corporation

They are stable,

inexpensive, and easy

to work with yet not

the fastest.

Next: MO Drive

MO drives

Magnetic Optic drives

You can only write to it,

when it is heated by a

laser beam to about

300 degrees Celsius

(The Curie point)

MO disks are fast,

inexpensive, and

extremely stable.

MO-technology is found

in Sony's recordable

MiniDisc.

Magnetic Storage

Hard Drive

What is a hard disk?

Also called a hard drive or a fixed disk

A rigid magnetic disk fixed permanently within a drive unit and used for storing computer data

Main storage device within a computer. “data center”

Next: Cross section

Hard Disk Geometrical Figure

Next: Chacracter

Characteristics of hard disk

Consists of several inflexible, circular platters that store items electronically A platter is coated with a material that allows items to be recorded

magnetically on its surface. The components of a hard disk are enclosed in an airtight, sealed case to

protect them

A Hard disk spins around thousands of times per minute(rpm) inside its metal casing, which is why it makes that whirring noise.

Capacity is determined by the number of platters. Standard systems come with hard drives between 40Gb and 250Gb.

Usually larger, usually faster, usually cheaper and usually fixed.

Shock resistant and sealed tightly.

Next: Basic Parts

Basic Parts of Hard Disk

Platter data/information is written.

Read and Write Head read and write/information data

on the surface.

Actuator mechanism responsible for the movement of

RW head for data access.

Spindle motor responsible for disk rotation

Next: Operation

Step 4: The head

actuator positions

the read/write

head arms over the

correct location on

the platters to read

or write data Step 4

Step 2: A small

motor spins the

platters while the

computer is

running

Step 2

Step 3: When

software requests a

disk access, the

read/write heads

determine the

current or new

location of the data

Step 3

Step 1: The circuit

board controls the

movement of the

head activator and a

small motor

Step 1

How does a hard disk work?

Next: Types

Types of Hard Disk

External Hard Disk Internal Hard Disk

Next: Speed

Measuring Speed of Hard Disk

Maximum Transfer Rate Highest amount of data that can be transferred per second.

100Mb/s for ATA100

66Mb/s - ATA66

Spindle Rotation Speed The rotation speed of the disk really is the basis of the other

two factors of hard disk speed. measured in rpm (revolution/min) usually 5400rpm or 7200 rpm

Seek Time The average time it takes for the disk to find the data you

need on the platters.

Next: Controller

Hard Disk Controllers

What is EIDE?

Enhanced Integrated

Drive Electronics

up to 4 HD w/

137GB/disk.

Transfer rate 133 Mbps

What is SCSI?

Small Computer System

Interface

up to 8 HD

Transfer rate 160 Mbps

Next: SATA

Hard Disk Controllers

SATA

Serial Advance

Technology Attachment

point to point channel

between drive.

Transfer rate up to 3GBps

Next: Adv and Dis

Advantages and disadvantages

Advantages Large storage capacity

Faster Data Access

Usually fixed inside the computer so cannot get mislaid.

Cheapest/MB

Can replaced and upgraded.

Can have several hard disk on a system unit.

Disadvantages Eventually fail

Susceptible to contaminants. head crash occurs when read and write head touches the surface

of a platter.

Not portable.

Next: Protection

Caring for your drive

1. Protect your drive from excessive jarring and

bumping.

2. Beware of static.

3. Perform periodic checks of your hard disk drive.

Disk scanning

1. Logical Scanning

2. Physical Scanning

Defragmenting

4. Place your hardware in a safe location.

5. Make Backups

Optical Storage

Optical Technology

• Optical Disk

• Optical Drive

Optical Medium

optical disk / compact

disk A flat, round, portable,

metal storage medium that usually is 4.75 inches in diameter and less than one-twentieth of an inch thick

Common to all modern computers

Available in a variety of formats.

1. CD

2. DVD

Next: CD

Compact Disk

Compact Disk originally used to store

music, in the form of digital audio, and now used as a data storage device, whence it is called a CD-ROM.

holds 650 MB up to 700 MB of data, instructions and information.

Developed by Sony and Philips in 1980, mass produced in 1982.

A. A polycarbonate disc layer has the data

encoded by using lands and pits.

B. A reflective layer reflects the laser back.

C. A lacquer layer is used to prevent

oxidation

D. Artwork is screen printed on the top of

the disc.

E. A laser beam reads the polycarbonate

disc, reflected back, and read by the

player. Next: How data is written

Step 3: Reflected light is

deflected to a light-sensing

diode, which sends digital

signals of 1 to the computer.

Absence of reflected light is

read as a digital signal of 0.

Step 1: A laser diode shines

a light beam toward the

compact disc.

Step 2: If light strikes a pit,

it scatters. If light strikes

land, it is reflected back

toward the laser diode.

Compact disc

label

Compact disc

label

lens lens

prism prism

laser

diode

laser

diode

Step 1

Compact disc

label

lens lens

prism prism

laser

diode

laser

diode

Items are stored using

microscopic pits

(indentations) and land

(flat areas) that are in the

middle layer of the disk

A laser light reads items

from the compact disc

Compact Discs

How does a laser read data on a compact disc?

Step 2

Compact disc

label

lens lens

prism prism

laser

diode

laser

diode

pit land

Step 3

Compact disc

label

lens lens

prism prism

laser

diode

laser

diode

Light-

sensing

diode

Light-

sensing

diode

0 1

pit land

Next: Types of CD

Types of CD

CD-ROM Compact Disk-Read Only Memory Read-only means you cannot write or save anything on

the disk.

CD-R Compact-Disk Recordable You can write only once.

CD-RW Compact Disk-Rewritable Allows rewriting many times.

You must have CD-RW software and a CD-RW drive.

Next: Figures

Next: DVD

DVD

Digital Versatile Disk An extremely high

capacity compact disc capable of storing from 4.7 GB to 17 GB

Looks just like a CD-ROM but data, instructions, and information is stored in a slightly different manner to achieve a higher storage capacity

You must have a DVD-ROM drive or DVD player to read a DVD-ROM.

Next: DVD Capacity

Capacity of DVD disks

Designation Sides Layers

(total)

Diameter Capacity

(cm) (GB) (GiB)

DVD-R SS SL (1.0) 1 1 12 3.95 3.68

DVD-R SS SL (2.0) 1 1 12 4.70 4.37

DVD-RW SS SL 1 1 12 4.70 4.37

DVD+R SS SL 1 1 12 4.70 4.37

DVD+RW SS SL 1 1 12 4.70 4.37

DVD-R DS SL 2 2 12 9.40 8.75

DVD-RW DS SL 2 2 12 9.40 8.75

DVD+R DS SL 2 2 12 9.40 8.75

DVD+RW DS SL 2 2 12 9.40 8.75

DVD-RAM SS SL 1 1 8 1.46 1.36*

DVD-RAM DS SL 2 2 8 2.65 2.47*

DVD-RAM SS SL (1.0) 1 1 12 2.58 2.40

DVD-RAM SS SL (2.0) 1 1 12 4.70 4.37

DVD-RAM DS SL (1.0) 2 2 12 5.16 4.80

DVD-RAM DS SL (2.0) 2 2 12 9.40 8.75*

Next: Capacity DVD vs CD

Capacity of DVD vs. CD

• Three storage techniques used to store DVD-ROM data

• Pits are packed closer together to make the disc more dense

• Two layers of pits are used, where the lower layer is

semitransparent so the laser can read through it to the upper layer

• Some are double-sided, which means you can remove the DVD-

ROM and turn it over to read the other side

Number of Sides 1 2

Number of Layers 1 2 1 2

Storage Capacity 4.7 GB 8.5 GB 9.4 GB 17 GB

Next: Caring for CD

Protecting Your Optical Disk

Do not expose the disks to excessive heat or

sunlight.

Do not touch the underside of the disks.

Do not write on the underside of the disks.

Do not stack the disks on top of one another.

Do store the disks in jewel boxes when not in

use.

Do hold disk by the edges.

Next: CD Drives

CD -ROM Drives

A device that reads data, instructions and information on a CD-ROM and CD-R.

Virtually all modern CD-ROM drives can also play audio CDs as well as Video CDs and other data standards when used in conjunction with the right software.

Next: Spped of CD-Rom

Transfer speeds for CD-ROM

Data Transfer Speeds

Transfer Speed KB/s Mb/s

1x 150 1.2288

2x 300 2.4576

4x 600 4.9152

8x 1200 9.8304

10x 1500 12.2880

12x 1800 14.7456

20x 3000 24.5760

32x 4800 39.3216

36x 5400 44.2368

40x 6000 49.1520

48x 7200 58.9824

50x 7500 61.4400

52x 7800 63.8976

56x 8400 68.8128

72x 10800 88.4736

Next: CD-R/RW Drive

CD-R/RW DRIVES

Recordable / ReWritable drives

also known as burners, writers

allow a user to create their own CDs of audio and/or data.

great for backup purposes and for creating your own audio CD compilations (not to mention other things like home movies, multimedia presentations, etc.).

Next: DVD Drive

DVD-ROM

DVD drives can also read CD-ROM drives, so you don't usually need a separate CD-ROM drive.

DVD drives have become low enough in price that there isn't much point in purchasing a CD-ROM drive instead of a DVD-ROM drive. “combo drive”

Next: DVD Speed

DVD Drive Speed

DVD drive speeds

Drive speed Data rate ~Write time (min)[24]

(Mbit/s) (MB/s) (MiB/s) SL DL

1× 10.80 1.35 1.29 61 107

2× 21.60 2.70 2.57 31 54

2.4× 25.92 3.24 3.09 25 45

2.6× 28.08 3.51 3.35 23 41

4× 43.20 5.40 5.15 15 27

6× 64.80 8.10 7.72 10 18

8× 86.40 10.80 10.30 8 13

10× 108.00 13.50 12.87 6 11

12× 129.60 16.20 15.45 5 9

16× 172.80 21.60 20.60 4 7

18× 194.40 24.30 23.17 3 6

20× 216.00 27.00 25.75 3 5

22× 237.60 29.70 28.32 3 5

24× 259.20 32.40 30.90 3 4

Next: DVD RW

DVD RW

Recordable /

Rewritable Drives

Could read almost all

optical media.

Used for backup large

amount of files

(multimedia).

Magnetic Tape

Magnetic Tape

A magnetically coated ribbon of plastic capable of storing large amounts of data and information at a low cost.

A tape drive reads from and writes data and information on a tape

Older computers used reel-to-reel tape drives

A tape cartridge is a small, rectangular, plastic housing for tape used in today‟s tape drives

Next: Uses of MT

Application of Magnetic Tape

Used by business and

home users to backup

personal computer hard

disks

Used to record phone

transactions.

Next: PC Card

PC Card

A credit card-sized device that adds memory, storage, sound networking and other capabilities to a portable pc.

Portable device allowing mobility of large amount of data.

Fits into a PC Card slot on a notebook other personal computer

Next: Other SD

Other Type of Storage

Storage Capacity Device Name Type, Use

Clik! Disk

CompactFlash

Microdrive

SmartMedia

40 MB

2 to 256 MB

1 GB

2 to 128 MB

Cartridge Digital cameras, notebook

computers

Memory Card Digital cameras, handheld

computers, notebook

computers, printers, cellular

telephones

Memory card Digital cameras, handheld

computers, music players,

video cameras

Memory Card Digital cameras, handheld

computers, photo printers,

cellular telephones

Next: Microfilm

Microfilm

A roll of film on which

a printed book, journal,

newspaper, or other

publication has been

reduced in size.

Next: Microfiche

Microfiche

A microfiche is a flat film 105 x 148 mm in size that carries a matrix of micro images.

Office size papers or magazine pages require a reduction of 24 or 25 for storage.

Microfiche are stored in open top envelopes which are put in drawers or boxes as file cards, or fitted into pockets in purpose made books.

Next: Life Span

Life Expectancy of Storage Devices

Computer

Communication

Lesson Objective:

At the end of this lesson the, students should be

able to:

Identify the required components for

communication. Identify the uses of communication.

Recognize the communication devices.

Differentiate the types of transmission media.

List the characteristics of transmission.

Computer Communication

Transfer of data, information and instructions

between two or more computers or devices.

Components of Communication System

Sending device Initiates instructions for

data/information/instructions

transmission

Receiving device Accepts transmission of

data/information/instructions.

Communication Device Connects sending device to the

receiving device

Communication Channel The transmission media on which

data/information/instruction travel.

Next: Cat of Channel

Communication Channel

The transmission media on which data,

information, and instruction travel.

carry the data from one computer to another.

Two Categories of Communication Channel

1. Physical Connections

solid or tangible medium to connect sending and

receiving devices.

2. Wireless Connections

Use intangible (air) substance to connect sending and

receiving devices.

Next: Physical

Physical Connections

Telephone Lines

consists of twisted-pair

cable which is made up of

hundreds of copper wires.

plugged in a wall

mounted jack.

use to be the standard

medium for voice and

data transmission.

Figure of Telephone Cable

Next: Coax

Physical Connections

Coaxial Cable

a high-frequency

transmission cable,

replaces the multiple

wires of telephone with a

single solid-copper core.

80 times faster than the

twisted-pair cable.

used to deliver tv signal

and pc network

connection.

Figure of Coaxial Cable

Next: Fiber

Physical Connections

Fiber-optic cable transmits data as pulses of light

through tiny tubes of glass or plastic.

26,000 times faster the transmission capacity of the twisted-pair.

lighter and more reliable at data transmission compared to coaxial.

rapidly replacing twisted-pair cable telephone lines.

Figure of Fiber-Optic Cable

Next: Wireless

Wireless Connection

Infrared

uses infrared light waves

to communicate over

short distances.

line-of-sight

communication

linear transmission

Use for transmitting data

from portable devices to a

computer.

broadcast radio

Broadcast Radio uses radio signal to

communicate with wireless devices.

used by cellular phone technology to place call/ connect to the Internet.

Web-enabled devices must follow WI-FI standard. Wireless Fidelity – communication

standard widely used to connect computers to each other and to the Net.

Next: Micrwave

Wireless Connection

Microwave uses high-frequency radio waves

than can only travel in straight line.

requires microwave stations with microwave dishes or antenna for long distance relay of data.

good for sending data; building to building or,

large college campuses. Bluetooth

Microwave

Bluetooth

short-range wireless

communication of

approximately 33 feet.

does not require line-of-

sight except metallic

barrier.

becoming standard for

connecting various

communication devices.

NextSattelite

Wireless Connection

Satellite uses satellite orbiting about 22,000

miles above the earth as microwave relay stations. Offered by Intelsat, International

Satellite Consortium owned by 114 government forming a worldwide communication system.

Could amplify and relay signals from one transmitter on the ground to another.

Used to send and receive

large volumes of data.

sending data to satellite is

called Uplink

receiving data to satellite is

called Downlink

can be interrupted by bad

weather.

Popular application

includes satellite tv and

GPS.

Next: App of Comm.

Uses of Computer Communication

1. E-mail

2. Voice Mail

3. Smart Phone

4. Instant Messaging

5. Telecommuting

6. Video Conferencing

7. Groupware

8. Global Positioning System (GPS)

9. Bulletin Board System (BBS)

10.E-Commerce

E-mail

Short for electronic mail transmission of electronic documents (messages and files) via computer

networks.

allows you to insert pictures, audio, video and animations.

allows multiple recipients

Voice Mail

E-mail system that

supports audio.

Computer voice mails are converted into digital form so that it can be stored in the voice mailbox in the computer.

Features of Voice Mail Program detailed log record of all calls (date, time, callerID)

messages are playable any time, can be forwarded, accessed via internet or saved for future use.

Smart Phone

Wireless telephone set that

allows sending of email, web

browsing, fax, intercom,

personal information

management, online banking

and remote data transfer

between phone and pc.

Function as portable office.

Instant Messaging

Real-time communication over the Internet that allows you to exchange messages and files with one or more people. works like phone except that you type.

new IM allows voice and video conferencing

Telecommuting

Allows employees to work at home, on a computer and then transmitting finished work to office via any available communication medium. teleporting

Advantages: reduces pollution.

saves gasoline.

less congested commuting environment.

Video Conferencing

Allows communication between two or more people to transmit real-time video and audio signal using computer. uses video device (pccam) but usually associated

with audio

used for business, socialization, or simple communication

Groupware

Class of software that

allows a group

attached to a local

network to organize

their activities.

Groupware Operations scheduling meetings and

allocating resource

password protection for documents

telephone utilities

electronic newsletters

file distribution

Global Positioning System

A navigation system consisting of one or more earth-based receivers and satellites, the signal of which are analyzed to determine location. GPS receiver

small, hand-held device with screen displaying the user‟s location on a map used to accept and analyze satellite signals.

BBS

Bulletin Board System is an electronic message centre that serves specific

interest group.

allows reviewing of and responding to posted messages

currently known as “forum”

E-Commerce

Electronic Commerce

commonly known as (electronic marketing) buying and selling products

electronically.

Common Types B2B

Business-to -business

B2C Business-to-consumer

popular example:

e-bay and Amazon.com

Next: Network

Network

What is a Network

Group of computer systems connected together.

connected using communication devices and

physical or wireless transmission media.

Next: Types

Types of Network

1. LAN – Local Area

Network

connection of computers

usually in one

geographically situated

in one area.

usually spans less than a

mile and are owned and

operated by individual

organizations.

used for file and

resources sharing across

short distances.

Next: MAN

Types of Network

2. MAN – Metropolitan-Area Network spans distances up o 100

miles.

Typically use wireless infrastructure or Optical fiber connections to link office buildings that are located throughout the city.

typically owned by group of organizations who jointly owned and operate the network

Next: WAN

Types of Network

3. WAN

Wide-Area Network

countrywide and worldwide

networks.

provides regional access

that spans more than 100

miles.

use microwave relays and

satellites to reach users

over long distances.

Next: Net arch

Network Architecture

Network Architecture

Describes how a network is arranged and how

resources are coordinated and shared.

Describes the physical arrangement of the

network.

encompasses different network specifications

including configurations and strategies

how information and resources are shared.

Topology

Refers to the geometric arrangement of a computer

system.

Next: Topology

Common Topologies

1. bus

2. ring

3. star

4. tree

5. mesh / fully connected Computer network can be

one of one or combination of

topologies.

Next: BUS

BUS

Devices are connected

to a central cable

called the bus or

backbone.

Each device handles

its own communication

control through the

bus.

Devices checked for

any information

intended for them.

Advantages and Disadvantages of

Bus Topology

Advantages relatively inexpensive yet easy to

install for small network.

sharing data stored on different computers.

Failure, adding, and removing of node from the network, does not affect other nodes

Disadvantages suitable for small network with few

computers

Entire network fails if there is any problem in the central cable

Difficult to identify the problem if the entire network shuts down.

Next: Ring

Ring

Devices are connected

to one another in the

shape of closed loop.

no central file server or

computer.

messages are passed

along the ring until it

reached its destination.

least frequently used.

mainframe mainframe

Advantages and Disadvantages of Ring

Topology

Advantages It is less expensive than star

topology.

Nodes can be easily added or removed.

they offer high bandwidth

Cable faults are easily located, making troubleshooting easier

Disadvantages Expansion to the network can

cause network disruption.

If a node fails, it affects the entire network

Next: Star

STAR

Devices are connected

to a central hub.

central hub – a device

that typically acts as a

host computer or file

server of the network.

Control is maintained

by polling

polling is a network

process of asking

whether it has a

message to send.

Advantages and Disadvantages

of Star Topology

Advantages supports time-sharing system.

Easy to install and manage.

You can easily add and remove nodes to and from the network without affecting the network.

Disadvantages bottlenecks can occur because

all data must pass through the hub.

If Hub fails the entire network is failed.

May require hub upgrade.

Next: Tree

TREE

Combines

characteristics of

linear bus and star

topologies.

Consists of groups of

star-configured

workstations connected

to a linear bus

backbone cable.

Advantages and Disadvantages of

Tree Topology

Advantages: Point-to-point wiring for individual

segments.

Supported by several hardware and software venders.

Disadvantages: Overall length of each segment is

limited by the type of cabling used.

If the backbone line breaks, the entire segment goes down.

More difficult to configure and wire than other topologies.

Next: Mesh

Mesh

Devices are connected with many redundant interconnections between network nodes.

point-to-point connection between every device on the network. Assuring continuous

connectivity between devices

Advantages and Disadvantages of

Mesh Topology

Advantages: Provides redundant paths

between devices

Failure of one node doesn‟t affect other node.

Expandable.

Disadvantages: Requires more cable than

the other LAN topologies.

Complicated implementation.

Next: Consideration

Considerations When Choosing a

Topology:

Money. A linear bus network may be the least

expensive way to install a network; you do not

have to purchase concentrators.

Length of cable needed. The linear bus network

uses shorter lengths of cable.

Future growth. With a star topology, expanding a

network is easily done by adding another

concentrator.

Cable type. The most common cable in schools

is unshielded twisted pair, which is most often

used with star topologies.

Communication Devices

hardware devices capable of transmitting data, information and instructions between a sending device and a receiving device. modems

network cards

wireless access points

gateway

routers

hub

bridge

repeater

switch

Modems

short for modulator/demodulator

a communication device that converts one form of a signal to another that is suitable for transmission over communication circuits

analog to digital / digital to analog

Types of Modem

Dial up modems usually comes in a form of an adapter card where a telephone cord is

connected.

uses the telephone lines.

ISDN & DSL sends and receives digital signal

Network Cards

also known as NIC, Network Interface Card

an adapter or PC card that enables a computer

device to access a network.

Wireless Access Points

acts as a central communication device, allowing

devices to transfer data information and

instructions wirelessly,

fitted with antenna to enhance transmission of

receiving signals

Gateway

A network point that acts as an entrance to

another network.

controls traffic within a company network or at a

local Internet Service Provider.

Routers

communication devices that can send packets

(blocks of data) to the correct LAN segment to

take them to their destination.

ensures that data are transmitted to the correct

devices in the network.

HUB

a device to which all clients and servers are wired.

it has the ability to regenerate the data bits on the

output side in order to maintain a strong signal.

Bridge

a device that connects a local network to another

local area network and passes packets between

two network segments that use the same

communication protocol.

Repeater

a device that extends communications over long

distances.

A hub switch or router can operate as a repeater.

Switch

A switch is a device that channels incoming data

from any multiple input ports to the specific output

port that will take the data toward its intended

destination.

Activity 4

Design a network architecture using the following specifications: Building 1 and Building 2 – 250 miles apart.

Building 1 consists of 5 departments. each department consists of 5 computers connected in star topology.

Building 2 consists of 8 departments. each department consists of 4 computers connected in bus topology.

Show using a block diagram: the set up of network for building 1

the set up of network for building 2

the set up of network for building 1 and 2

Describe the Type of Network used

Describe the Type of Communication Channel used

Describe the Types of Communication Device used.

Assignment: Activity 3

What is communication device? Search for the following communication devices:

1. modems and types

2. network cards

3. wireless access points

4. gateway

5. routers

6. hub

7. bridge

8. repeater

9. switch a) Define each of them

b) discuss their function

c) attached pictures

d) list down their advantages and disadvantages

Should be hand-written

and compiled in a yellow

paper with picture pasted

on it.

7/27/2012 283

“ There is no such Thing as

protected computer”

Data Security

and

Protection

Learning Objective:

After this Lesson the students should be able to:

Identify the different types of data problem

Enumerate the causes of data problem.

Categorize different destructive or harmful

programs.

List the effects of destructive programs.

Enumerate ways on how to protect and prevent

destructive files from destroying our computer files.

DATA PROBLEM

Types of Data Problem

Lost data or Missing Data – consists of data that

is inaccessible, usually because of accidental

removal.

Stolen data – not necessarily missing, but has

been accessed or copied without authorization.

Inaccurate data – consists of data that is not

accurate because it was entered incorrectly, it

was deliberately or accidentally altered, or it was

not edited to reflect current facts.

Causes of Data Problem

1. Operator Error – refers to a mistake made by a computer user.

2. Power Problem

Power Failure – complete loss of power.

Power Spikes – is a sudden increase in power.

Power Surge – sudden increase in power, longer than spike.

Electronically Protective Device 1. UPS – uninterruptible power supply, designed to provide

enough power to keep your computer running momentarily.

2. surge strip – protect computer and modem from from power spikes and surges, but does not contain a battery to prolong the power of your computer.

3. AVR – Automatic Voltage Regulator, protect the circuit from spikes or surges by regulating the output power.

Causes of Data Problem

3. Hardware Failure – is data problem caused by

peripheral breakdown.

4. Fires, Floods and Other Disasters.

5. Viruses and Other Malicious Programs.

Computer Crime

an illegal action in which perpetrator uses a special knowledge of computer technology.

Computer Criminals can be:

1. Employees – largest category with the easiest access to computers.

2. Outside Users – clients/suppliers who has access to computer system.

3. Hackers and Crackers

Hackers are people who gain unauthorized access to a computer system for the fun and challenge of it

Crackers do the same thing but for malicious purpose only.

4. Cyberpunks

are people who creates and spreads annoying program on the internet.

5. Organized Crime – cyber fraud

6. Terrorists – potentially damage navigation system and government communication system.

Programs they created

Malware short for malicious

software specifically designed to

damage or disrupt a computer system

Most common Malware 1. Viruses

2. Worms

3. Trojan Horses

Programs they created

Spyware designed to intercept or take

partial control of a computers operation without the informed consent of that machine‟s operator.

gathers users information

records keystrokes, history, passwords, and other information.

hard to detect.

Programs they created

Adware

software that

periodically pops up

advertisements on a

user‟s computer.

sometimes integrated

into or bundled with a

program.

Programs they created

Spam e-mails that are not

requested.

also known as “junkmails”

advertising strategy.

How do companies know our e-mail addresses?

Categories of Destructive

Programs

Computer Virus

Trojan Horses

Time Bombs

Logical Bombs

Worms

Computer Virus

a program that attaches itself to a file, reproduces itself, and spreads to other files. activate when its associated file is executed. Virus deliver its payloads – „ultimate mission‟

Types of Virus file virus

virus that attaches itself to an application program such as game and application programs.

boot sector virus infects the system files that your computer uses

every time you turn it on.

macro virus infects a set of instructions called macro.

macro – is essentially a miniature programs that usually contains legitimate instructions to automate document and worksheet production.

Computer Virus

Causes of Computer Virus Infection Exchanging infected storage

devices. Downloading of illegitimate file,

software or programs. Copying and opening file, software,

or programs from unreliable sources. (file sharing)

Opening or downloading e-mail attachments from unknown sender.

Using storage device from an infected computer. effect

Effects of Computer Virus Infection It can corrupt or destroy

data.

Disrupt computer operations.

Could crash computer system

Symptoms of Computer Virus

Infection

Displaying of vulgar, embarrassing, or annoying

messages.

Developing unusual visual or sound effects.

Difficulty accessing of files or mysteriously

missing of files.

Changes in performance.

Unexpected reboots.

Changes in file size especially executable files.

Trojan Horse (is it a virus?)

a computer program that appears to perform one function while actually doing something else. notorious for stealing passwords using

a keyloggers keylogger – a type of program that

records your keystrokes. diff bet virus and trojan

Difference between Trojan and Virus Trojan might contain virus. Trojan is not designed to make a copy

of itself. Trojan are standalone programs.

„crackers delight‟

Causes, Symptoms and Effects

Causes of Trojan Horse Infection Downloading, copying and opening software or programs from

unreliable sources.

Opening or downloading e-mail program attachments from unknown sender.

Entering password and username to illegitimate login screen on a network.

Symptoms of Trojan Horse Infection Difficulty opening program or mysteriously missing of executables. Changes in performance. Appearance of unknown programs. Alterations of password protected accounts.

Effects of Trojan Horse It can steal passwords or breach one system. It can corrupt or destroy data.

Time Bomb and Logic Bomb

Time Bomb a computer program that

stays into your computer system undetected until it is triggered by a certain event in time. It could reside in your

computer without discovery. Might contain virus

Logic Bomb a computer program that

is triggered by the appearance or disappearance of specific data.

Causes, Symptoms and Effect

Causes of Time Bomb and Logic Bomb Downloading, copying and opening software or programs

from unreliable sources.

Opening or downloading e-mail program attachments from unknown sender.

Logic Bomb on the other hand can be created by a company programmer/employee.

Symptoms of Time and Logic Bomb

Difficulty opening program or mysteriously appearance of

executables files.

Changes in performance.

For Time Bomb: Lost or Missing Data.

Effect of Time or Logic Bomb

It can corrupt or destroy data.

Destroy computer system

Worms

Worm (is it a virus?) a program designed

to enter a computer system – usually a network – through security “holes”.

has the ability to copy itself from machine to machine.

302

Causes and Effects

Causes of Worm

Opening or downloading e-mail program attachments from unknown sender.

Accessing files from worm infected network server.

Effects of Worm

Filled up storage device.

Affects computer performance.

Disrupting access to file, programs, Web pages, and other services provided by the network.

Designed to attack network servers.

Protection and Prevention

Use virus monitoring and cleaning software.

Use worm detecting and cleaning software.

Observe the status of files and performance of your computer.

Create backup of database or records.

Avoid downloading files / programs from illegitimate sites.

Avoid opening email attachments from unknown sender.

Avoid opening files/programs from unreliable sources.

If using storage device to other computer, make sure it is using anti-virus software.

Never use your password and username to unknown logins.

Use firewall. firewall – a combination of hardware and software that provides security system,

usually to prevent unauthorized access from outside to an internal network or intranet.

Most Damaging

Malicious Software

1. Melissa

2. Sub7Trojan

3. I love You Virus

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Melissa

The Melissa worm, also known as "Mailissa",

"Simpsons", "Kwyjibo", or "Kwejeebo", is a mass-

mailing macro virus, hence leading some to

classify it as a computer worm.

History

Written by David L. Smith in Aberdeen Township,

New Jersey, and named after a lap dancer he

encountered in Florida.

First found on March 26, 1999, Melissa shut down

Internet mail systems that got clogged with infected

e-mails propagating from the worm.

Melissa was not originally designed for harm, but it

overflowed servers and caused unplanned problems

Worm specifications

Melissa can spread on word processors Microsoft

Word 97 and Word 2000. It can mass-mail itself

from e-mail client Microsoft Outlook 97 or Outlook

98.

If a Word document containing the virus, either

LIST.DOC or another infected file, is downloaded

and opened, then the macro in the document runs

and attempts to mass mail itself.

When the macro mass-mails, it collects the first

50 entries from the alias list or address book, and

sends it to the e-mail addresses of those names.

Variants

Melissa.U This variant deletes critical files. Before deleting the files, it strips

them of their archive, hidden, and read-only attributes.

Melissa.V It uses Microsoft Outlook, and tries to send itself to the first 40

addresses in address book. subject line: "My Pictures (<Username>)", where <Username> is the

name to whom the sender's copy of Microsoft Word is registered.

payload is triggered immediately when infected attachment is opened.

Once complete, it beeps three times and displays a message : "Hint: Get Norton 2000 not McAfee 4.02".

Melissa.AO

This is what the e-mails from this version contain:

Subject: Extremely URGENT: deceit

To All E-Mail User - <current date>

Attachment: <Infected Active Document>

Body: This announcement is for all E-MAIL user. Please take note that our E-Mail Server will down and we recommended you to read the document which attached with this E-Mail.

Melissa.AO's payload occurs at 10 a.m. on the 10th day of each month. The payload consists of the worm inserting the following string into the document: "Worm! Let's We Enjoy."

Sub7Trojan

Sub7 is the most famous Trojan/backdoor application ever. It has been a hacker‟s

perennial favorite since the late 90s.

When Sub7 is installed on the PC, a backdoor is created attackers are notified, and this is from here that the real fun begins.

310

I Love You Virus

The ILOVEYOU virus, also known as VBS/Loveletter and Love Bug virus, is a computer virus written in VBScript.

Description

The virus arrived in e-mail boxes on May 4, 2000, with the simple subject of "ILOVEYOU" and an attachment "LOVE-LETTER-FOR-YOU.TXT.vbs". Upon opening the attachment, the virus sent a copy of itself to everyone in the user's address list, posing as the user.

Two aspects of the virus made it effective: It relied on social engineering to entice users to open the

attachment and ensure its continued propagation.

It exploited the weakness of the email system design that an attached program could be run easily by simply opening the attachment;

Spread

From Philippines across West

Used mailing lists as source of targets

Pretended to be from an acquiantance so might be

considered "safe”.

Few users to open the file was all it took and

generated thousands and thousands of e-mails

that would cripple e-mail systems under their

weight

Effects

It began in the Philippines on May 4, 2000, and spread across the world in one day (traveling from Hong-Kong to Europe to the United States), infecting 10 percent of all computers connected to the Internet and causing about $5.5 billion in damage.

The Pentagon, CIA, and the British Parliament had to shut down their e-mail systems to get rid of the virus, as did most large corporations.

This particular malware caused widespread outrage, making it the most damaging virus ever. The virus overwrote important files, as well as music, multimedia and more, with a copy of itself. It also sent the virus to everyone on a user's contact list.

This particular virus only affected computers running the Microsoft Windows operating system.

Detection

Narinnat Suksawat, a 25-year-old Thai software

engineer, was the first person to write software that

repaired the damage and release it to the public on

May 5, 2000, 24 hours after the worm had spread.

"Rational Killer", the program he created, removed

virus files and restored the previously removed

system files so they again functioned normally.

Two months later, Narinnat was offered a senior

consultant job at Sun Microsystems and worked

there for two years.

UK company MessageLabs shot to fame when

their anti-virus software, Skeptic, proactively

detected the attachment as malware, thus

automatically protecting all of their customers.

The first copy intercepted by them was stopped at

00:43:26 4 May 2000 UTC, and originated from an

email address in the Philippines, going to an email

address in the UK. It is likely that the email was

from one of the first few rounds of replication of the

virus.

Variants

Attachment: LOVE-LETTER-FOR-YOU.TXT.vbs Subject Line: I LOVEYOU Message Body: kindly check the attached LOVE LETTER coming from me.

Attachment: mothers day.vbs Subject Line: Mothers Day Order Confirmation Message Body: We have proceeded to charge your credit card for the amount of $326.92 for the mothers day diamond special. We have attached a detailed invoice to this email. Please print out the attachment and keep it in a safe place.Thanks Again and Have a Happy Mothers Day! mothersday@subdimension.com

Variants

Attachment: virus_warning.jpg.vbs

Subject Line: Dangerous Virus Warning

Message Body: There is a dangerous virus

circulating. Please click attached picture to view it

and learn to avoid it.

Attachment: protect.vbs

Subject Line: Virus ALERT!!!

Message Body: a long message regarding

VBS.love letter.A

Variants

Attachment: Virus-Protection-Instructions.vbs Subject Line: How to protect yourself from the IL0VEYOU bug! Message Body: Here's the easy way to fix the love virus.

Attachment: Arabian.TXT.vbs Subject Line: Thank You For Flying With Arab Airlines Message Body: Please check if the bill is correct, by opening the attached file

Attachment: Picture.vbs Subject Line: Is this you in this picture? Message Body: Is this you in this picture?

Legislative aftermath

As there were no laws in the Philippines against virus-

writing at the time, on August 21, 2000, the prosecutors

dropped all charges against Onel A. de Guzman in a

resolution signed by Jovencito Zuno. The original charges

brought up against de Guzman dealt with the illegal use of

passwords for credit card and bank transactions. The

Philippines E-Commerce Law (Republic Act No. 8792),

passed on June 14, 2000, laid out penalties for

cybercrime. Under the law, those who spread computer

viruses or otherwise engage in cybercrime (including

copyright infringement and software cracking) can be fined

a minimum of 100,000 pesos (about USD$2,000), and a

maximum commensurate with the damage caused, and

imprisoned for six months to three years.

Defenses against

Data Problem

1. Antivirus (short-term)

2. Data Backup (long-term)

Anti-virus Software

Antivirus Software sometimes referred to as a virus detection software,

examines the files stored on a disk to determine whether they are infected with a virus, then disinfects the disk, if necessary.

Virus Detection Techniques Change in length or size detection.

Checksum calculation. Checksum – a number that is calculated by combining the

binary values of all bytes in a file.

Virus Signature checking. Virus signature – is a unique series of bytes that can be used to

identify a known virus, much as fingerprint is used to identify an individual.

Virus Checking Method Automatic – background monitoring

Manual – scheduled or manual checking.

About Antivirus:

When Should we use Antivirus Software?

all the time

How often should we update?

destructive programs variants are unleashed almost everyday.

Download various definitions as often as every other day.

How reliable is antivirus software?

Multi-partite virus – are able to infect multiple types of targets.

Polymorphic viruses – mutate to escape detection by changing their signatures.

Stealth viruses – remove their signatures from a disk-based file and temporarily conceal themselves in memory.

Data Backup

Why Do We Need Backup?

helps recover data that‟s been wiped out be

operator error, viruses, or hardware failures.

How to make backup?

Backup is a copy of one or more files that has been

made in case the original files become damaged.

usually stored in a different medium from the original

files.

Depends on your backup software.

Data Restoration

Data Restoration is the process of copying files

from a backup to the original storage medium or its

replacement.

Restoring data is as simply as copying from backup

medium to your original storage, and as completed

as performing series of steps based on your backup

technology.

Backup Plan

1. Decide how much of your data you want, need, and can afford to back up

2. Create a realistic schedule for making backups.

3. Make sure you have a way to avoid backing up files that contain viruses.

4. Find out what kind of boot disks you might need to get your computer up and running after a hard disk failure or boot sector virus attack.

5. Make sure you can test your restore procedure so that you can successfully retrieve the data you‟ve backed up

6. Find a safe place to store your backups.

7. Decide what kind of storage device you‟ll use to make backups.

8. Select software to handle backup need.

Types of Backup

Full-system backup

contains a copy of every program, data, and system file on a

computer.

Advantage:

Easy restoration of system

Disadvantage

Takes a lot of time

requires large capacity storage backup device

Selective Backup

contains only your most important data file.

Advantage

easy to restore

Disadvantage

You must manually reinstall all your software and programs

Backup Devices

Factors in selecting a backup device 1. Value of your data

2. Current equipment

3. Budget

What is the easiest way to back up important data?

Through the use of CD or DVD.

Disadvantage

Writing process is slow

Requires special backup software.

Monitor the backup process

Switch disks occasionally

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