CHAPTER 2:HARDWARE AND SOFTWARE

Information Technology and Managerial Applications in

Business

Objectives2

What hardware and software are and how they work together

What sequence of inventions contributed to the development of modern computers

What binary is and why the standardization of data representation is important

What the components of a computer areWhat an operating system is and why it is importantWhat application programs are and which are

importantHow software is designed and programmed and who

owns it

Computer3

A computer is a machine that can be programmed to accept data and process it into useful information

The Jacquard loom was invented in 1801 by Joseph Jacquard

Computers designed and constructed from devices, such as electronic circuits, relays, vacuum tubes, etc are referred to as first-generation computers

ABC was the first electronic digital computer deviceThe Colossus, an early electronic digital computer,

was used by British code breakers to read encrypted German messages during WWII

Computer Cont.4

ENIAC (Electronic Numerical Integrator and Computer) is considered to be the first modern general-purpose computer

Transistorized computers are referred to as second-generation computers

Computers manufactured as large scale were referred to as mainframe computers

Minicomputers were smaller, but mostly no different from mainframes

Integrated circuit combines numerous transistors and other electronic components

Computers Cont.5

Third-generation computers were started by mass production and enhanced reliability

Microprocessor made possible the development of microcomputers, small, low-cost computers that could be owned by individuals and small businesses

Microcomputers are known today as personal computers

Review Section 16

1. How do application and system software differ?

2. Why is hardware necessary for data to become visible?

3. From the standpoint of processing data, what was the significance of Hollerith’s invention?

4. Why did Babbage’s reliance on decimal-based architecture instead of binary-based architecture make his machine difficult to produce?

5. How did the development of the integrated circuit make possible the development of the microprocessor?

Modern Hardware7

The motherboard is the single component of a computer system that ties all other components together

The CPU, RAM, and other basic components on the motherboard

The CPU is the critical component in a digital computer that processes data by executing instructions that are contained in computer programs

The CPU contains the control unit and the ALU

Modern Hardware8

A bus is a subsystem of the motherboard that transfers data or power between computer components inside a computer or between a computer and external components that are typically controlled by device driver software

Computers have internal and external busesControl bus is used by CPUs for sending

commands to other devices within the computerAddress bus carries the information about which

device the CPU is communicating withData bus carries the actual data being processed

Modern Hardware9

The USB (Universal Serial Bus) allows peripheral devices to be connected without the need to plus expansion cards into the computer’s external bus

A USB port is an extension of the external busHot-swapped is when a device is connected or

disconnected without powering down or rebooting the computer

Basic Input/Output System (BIOS) is a small program run by a computer when first powered on

The Operating System provides a set of services for the programs running on a computer and provides the fundamental interface for use of the computer

Modern Hardware10

Once in setup mode, numerous options are available, including: System time/date Drive configuration Boot sequence Mouse/keyboard Security Power management Exit

Modern Hardware11

The most common input devices are a keyboard and a mouse

The keyboard allows you to type a document, use keystroke shortcuts, access menus, etc.

The mouse is a point-and-click interface for entering commands that works well in graphical environments

The most common output devices are monitors, printers, and speakers

A monitor displays signals generated by a computer as images on a screen

A printer is the device that puts data or information on paper

Review Section 212

1. What is the role of a bus? Why does a computer have several?

2. Why is the motherboard considered a critical component of the computer?

3. Why are microphones and cameras input devices?

4. Today most printers are non-impact. Can you think of a situation that would call for use of an impact printer?

Storage13

Primary memory is temporary, but fast storage; secondary memory is permanent storage

The name for primary storage is RAM (Random Access Memory) and it is volatile, which means when the computer is shut off, any program or data within it is lost

Primary storage is usually measured in gigabytes; the capacity, or amount of memory, is measured in bytes

Storage14

Name Amount of BytesKilobyte (KB) 1,000Megabyte (MB) 1,000,000Gigabyte (GB) 1,000,000,000Terabyte (TB) 1,000,000,000,000

Storage15

RAM is packaged in many configurations: DIP (dual-inline packages), SIMM (single-inline memory module), DIMM (dual-inline memory module)

Difference between SIMMs and DIMMs is that DIMMS can transfer twice the amount of data in a single operation

DIMMS come in two configurations: SDRAM and DDR SDRAM

Storage16

Cache memory is special memory that operates much faster than SDRAM memory

Virtual memory is a memory management technique used by multi-tasking computer operating systems such as Windows

CPUDate in cache?

Cache

RAMFaster

Slower

Storage17

Secondary storage is persistent, which means it holds data and programs even when there is now power in the computer

Hard disks are measured in gigabytesData transfer rate – the number of bytes per

second that the drive can deliver to the CPUSeek time – The amount of time between when

the CPU requests a file and when the first byte of the file is sent to the CPU

Latency time – The average delay until a desired sector rotates to under the read/write head

Storage18

Disk fragmentation is when new programs are installed or large files saved, the hard drive tries to fill the holes, thus breaking up the program or file into blocks

It is desirable for files to be stored in contiguous blocks because the entire file can be accessed faster

The directory is a list of folders and files on the disk with references to the specific physical location of each file on the disk

The logical location is what folder the file is inThe operating system must know the actual physical

location of each file so that it may be opened when the user requests it. This relationship is known as logical to physical mapping

Storage19

A scrubber is a special program that overwrites each bit of data with a 0

A floppy disk is similar to a hard disk because it stores data on a surface that rotates, but the platter is a flexible circular piece of metal-coated plastic

Flash memory is attractive because it is nonvolatile, offers fast read access times, and has better shock resistance than hard disks

Flash memory is solid state, or an integrated circuit and not rotational like a disk

A CD-ROM is a compact disc that contains data accessible by a computer using a CD-ROM drive

Storage20

DVD is an optical rotational storage media format that can be used for storage of any type of data

Zip disks are removable cartridge storage devices that may be generally used to store compressed data

A type drive is a data storage device that reads and writes data stored on a magnetic tape

Tape drives only allow for sequential access of dataA modem is a device that modulates a carrier’s

signal to encode a computer’s digital data, and later demodulates the signal to decode the data at the receiving end.

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Broadband is a high-data-transmission-rate internet connection

Digital Subscriber Line (DSL) is a technology that provides high-speed digital data transmission over the wires of the local telephone network, which is known as the local loop

Such open signals can present a security risk for three reasons: Intercepted data – Data transmitted “over the air” can be

intercepted Security breach – Intrusions into the computer system are possible Unauthorized use – Illegitimate use of the wireless router can slow

down the transmission rates of legitimate users

Review Section 322

1. Why does a computer system require persistent storage?

2. What is the role of RAM in a computer?3. Why does a disk become fragmented, and

why is that a problem?4. Why does virtual memory assist in enabling

multitasking?

Computer Styles23

Mainframes are computers used mainly by large organizations such as government agencies, large companies, universities, the military, and research laboratories for missions critical requirements

A supercomputer is a machine that processes data exceptionally fast and are used for calculation-intensive tasks such as economic and weather forecasting, climate research, molecular modeling, simulations of physical events, and computer-based cryptography

Moore’s Law24

Moore’s Law is based on the empirical observation made in 1965 by Gordon E. Moore, a co-founder of Intel

Different Coding Standards

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1. ASCII and EBCDICASCII (American Standard Code for Information Interchange): coding system traditionally used with PCs

2. EBCDIC (Extended Binary-Coded Decimal Interchange Code): developed by IBM, primarily for mainframe use

3. Unicode: newer code (32 bits per character is common); universal coding standard designed to represent text-based data written in any language

Different Coding Standards

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Coding Systems for Other Types of Data

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Graphics (still images such as photos or drawings)

Bitmapped images: A variety of bit depths are possible (4, 8, 24 bits)

Vector-based images: Use mathematical formulas to represent images rather than a map of pixels

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Coding Systems for Other Types of Data

Graphics (still images such as photos or drawings)

Bitmapped images: A variety of bit depths are possible (4, 8, 24 bits)

Vector-based images: Use mathematical formulas to represent images rather than a map of pixels

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Coding Systems for Other Types of Data

Audio data: Must be in digital form in order to be stored on or processed by a PC Often compressed when sent over the Internet

MP3 filesVideo data: Displayed using a collection

of frames, each frame containing a single graphical image Amount of data can be substantial, but can be

compressed MPEG-2 files

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Inside the Computer System Unit

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Ports and Connectors

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Typical CPU Components

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The System Clock and the Machine Cycle

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The System Clock and the Machine Cycle