tech guide a the details of it hardware and software © john wiley & sons canada, ltd.a-1

Tech Guide A Tech Guide A The Details of IT The Details of IT

Hardware and SoftwareHardware and Software

© John Wiley & Sons Canada, Ltd. A-1

What We Will Cover

• An Overview of Hardware

• Hardware Devices

• Operating Software

• Application Software


AN OVERVIEW OF AN OVERVIEW OF HARDWAREHARDWARE

Hardware is the physical component of IT.

Hardware consists primarily of electronic devices (mostly digital) with some electro-mechanical parts used with input, output, and storage devices.


EVALUATING HARDWARE EVALUATING HARDWARE DEVICESDEVICES Cost: We want the device to be within

our budget and provide the most value.

Compatibility: We need hardware that works correctly with the other devices so as to form a system.

Data and information needs: We want our IT devices to work with data and information in a specific way.

Accuracy: We want our devices to handle data and instructions accurately.


Speed: We want to work as quickly and efficiently as possible.

Portability: We often want our devices to be portable. (Actually, we want our ability to work with information to be portable.)

Form factor: The size, shape, and physical arrangement of IT affects how and where we use it.


EVALUATING HARDWARE EVALUATING HARDWARE DEVICESDEVICES

TRANSISTORSTRANSISTORSThe primary component of

computing hardware is the transistor.

Transistors are electronic switches that can be on or off.

We can assign meaning to the state of a transistor:

On = 1 Off = 0


BINARY NUMBERSBINARY NUMBERS

The binary number system is a convenient number system that uses only the digits 1 and 0.

The basic unit of the binary number system is a bit (binary digit).

8 bits = 1 byte = 1 character


RELATING BINARY AND RELATING BINARY AND DECIMAL VALUESDECIMAL VALUES23410 = 20010 + 3010 + 410 = 2*102 + 3*101 + 4*100

111010102 = 1*27 + 1*26 + 1*25 + 0*24 + 1*23 + 0*22 + 1*21 + 0*20

= 12810 + 6410 + 3210 + 010 + 810 + 010 + 210 + 010

= 23410

Converting decimal numbers to binary is also straightforward (see Table A.1 in the text).

Using binary to encode data is at the heart of everything that goes on in a computer.


CHARACTER ENCODINGCHARACTER ENCODING

Binary codes represent letters and numbers through character encoding.

Character encoding permits a specific combination of bits to represent each character.


ENCODING SCHEMESENCODING SCHEMESExtended Binary Coded Decimal

Interchange Code (EBCDIC): original code used for mainframes

Standard ASCII (American Standard Code for Information Interchange): original code for personal computers

Unicode: used for all personal computers today


COMPARISON OF COMPARISON OF ENCODING SCHEMESENCODING SCHEMESCharact

erEBCDIC ASCII Unicode

A 1000 0001 0110 0001 0000 0000 0110 0001

A 1100 0001 0100 0001 0000 0000 0100 0001

Esc 0010 0111 0001 1011 0000 0000 0001 1011

% 0110 1100 0010 0101 0000 0000 0010 0101

2 1111 0010 0011 0010 0000 0000 0011 0010

Not available

Not available

0000 0011 1100 0000

⅔ Not available

Not available

0010 0001 0101 0011


MACHINE INSTRUCTIONSMACHINE INSTRUCTIONS Hardware devices execute instructions as a sequence

of binary strings known as machine instructions. The sequence used to represent a specific instruction

is assigned in a similar manner as that used to assign binary sequences to character data (e.g., the ASCII code).


IMPORTANT POWERS OF IMPORTANT POWERS OF TWOTWO

Power of 2

Decimal Value Description

23 8 Number of bits in a byte

28 256 The number of characters that a byte can code

210 1024 1 kilobyte (KB)

220 1,048,576 1 megabyte (MB)

230 1,073,741,824 1 gigabyte (GB)

Because computers use the binary number system, all measures are in powers of two.


PROCESSING HARDWAREPROCESSING HARDWAREThe microprocessor contains the

components that make up the central processing unit (CPU).

The CPU works with memory to control the execution instructions and the processing of all data.

The performance of the CPU is key in determining the processing capability of IT devices.


KEY CPU COMPONENTSKEY CPU COMPONENTSControl UnitArithmetic Logic Unit

(ALU)Floating Point Unit

(FPU)Decode UnitCache Memory Prefetch UnitRegistersClockBusInstruction Set


CPU FUNCTIONSCPU FUNCTIONS1. Fetch: Obtain and write the next

part of an instruction to the proper location of the instruction cache.

2. Decode: Send current instructions from the instruction cache to the decode unit.

3. Execute: Start processing calculations within the arithmetic logic unit (ALU) and control the flow of data.

4. Store: Write instruction results to the memory location.


DATA AND INSTRUCTION DATA AND INSTRUCTION FLOW IN THE CPUFLOW IN THE CPU


CPU PERFORMANCECPU PERFORMANCE Three basic characteristics can be

used to differentiate microprocessors: ◦ Instruction Set: A set of machine

language instructions that the microprocessor can execute

◦ Bandwidth (bus size): The number of bits that can be processed by the CPU in a single instruction

◦ Clock Speed: Expressed in megahertz (MHz), the clock speed controls how many instructions per second the CPU can execute


INTERNAL MEMORY: ROMINTERNAL MEMORY: ROM

Read only memory (ROM): permanent memory that contains instructions and data that cannot be altered

The main purpose of ROM is to hold instructions that are used to control the computer’s start-up processes (booting up).

This small set of instructions is known as the BIOS (basic input/output system).


INTERNAL MEMORY: RAMINTERNAL MEMORY: RAM Random access memory (RAM): the

main short-term memory in a computer◦ Access to RAM is much faster than access

to secondary storage.◦ Memory capacity is measured in terms of

the bytes that may be stored (kilobytes: KB; megabytes: MB; gigabytes: GB; terabytes: TB).

◦ The size of the CPU address bus determines the maximum number of memory locations that can be addressed.


TYPES OF RAMTYPES OF RAMDynamic RAM (DRAM): The

majority of RAM. Data in an array of chips that has to be electronically refreshed several hundred times a second; if the array loses its charge, all data held there is erased.

Static RAM (SRAM): It is faster and less volatile than DRAM, but much more expensive.

Peripheral RAM: It is often found in the peripheral components (like printers or video cards) of your information system.


HARDWARE DEVICESHARDWARE DEVICES

Input hardware: Serves as the interface for

entering data and information Converts data and information

into binary form


TYPES OF INPUT TYPES OF INPUT HARDWAREHARDWAREKeyboardPointing devices: mouse, touchpad,

joystick, touch screen, trackball, pen input, light pen, wearable devices, tablet

Scanning devices: document scanner, bar code reader, magnetic strip reader, OMR, OCR, MICR, biometric scanner, smart card/chip reader

Audio input: microphoneOptical input: digital camera, WebCamSensors


INPUT DEVICESINPUT DEVICES


OTHER INPUT DEVICESOTHER INPUT DEVICESAudio Input – primarily through

microphone◦e.g., used to store audio comments, dictation

Musical instrument digital interface (MIDI) ◦Allow note and effect information to be stored

Video input – captured using camera, WebCam, etc.

Sensory input – measures physical quantity like temperature and converts it into an electronic signal


OTHER INPUT DEVICESOTHER INPUT DEVICESSelecting input devices

◦Ergonomic considerations◦Environmental conditions◦Performance

Accuracy Resolution Tracking Speed


OUTPUT HARDWARE OUTPUT HARDWARE COMPONENTSCOMPONENTS

Output hardware:Serves as the

interface for receiving data and information

Converts data and information from binary form into a more useful form

Display System


TYPES OF OUTPUT TYPES OF OUTPUT HARDWAREHARDWARE

Display devices: LCD, touch screens Printers: laser, inkjet, thermal,

multifunctional devicePlotters: flatbed, drum, electrostatic


OUTPUT HARDWARE OUTPUT HARDWARE DEVICES: DISPLAYDEVICES: DISPLAYLCD Monitors

◦Consists of liquid crystal material placed between a pair of transparent electrodes

◦Can change the phase of light that passes through it

◦Consists of an array of cells (pixels) that can be individually controlled


DISPLAY DEVICE DISPLAY DEVICE PERFORMANCEPERFORMANCE

Resolution is the maximum number of pixels that the screen can show.

Dot pitch of a display is the distance between the pixel and the closest pixel of the same colour - usually .30mm.

Refresh rate is the number of times the display is refreshed per second.


TOUCH SCREEN DEVICESTOUCH SCREEN DEVICESA touch screen

monitor is a computer display screen that is sensitive to human touch or a special pen.

Kiosks, such as ATMs and self-service checkout lanes, PDAs, and tablet PCs frequently use touch screens.


PRINTED OUTPUT PRINTED OUTPUT DEVICESDEVICES


STORAGE DEVICESSTORAGE DEVICESStorage refers to various non-volatile

media and devices used for storing large amounts of data and instructions.

Storage capacity is measured in terms of the bytes (kilobytes: KB; megabytes: MB; gigabytes: GB; terabytes: TB).


TYPES OF STORAGE TYPES OF STORAGE DEVICESDEVICESMagnetic disks: diskette, hard disk

drive, high capacity diskettes, tapeOptical disks: CD-ROM (-R, -RW),

DVD (-R, -RW, -HD, -Blu-ray)Chip-based storage: USB flash drives


STORAGE HARDWARE STORAGE HARDWARE Magnetic Disks are used as a form

of direct-access storage.◦Information may be accessed in any order.

Disk drives spin the disk while reading and writing information onto it.

Hard disks serve as the main storage device for programs.

Optical disks use a laser to read and write data.


STORAGE HARDWARESTORAGE HARDWAREFlash memory is a type of chip-

based memory that: ◦can be written to, as well as read

into internal memory◦is known as USB flash drives


OPERATING SOFTWAREOPERATING SOFTWAREREVIEW OF SOFTWARESoftware includes all of the instructions given to the computer’s hardware.There are two major categories of software:

◦operating systems software◦application software

All software has to be created by human programmers using a variety of computer languages that the computer can implement.


OVERVIEW OF THE OVERVIEW OF THE OPERATING SYSTEMOPERATING SYSTEMThe operating system (OS): is a collection of software programs

that manages the tasks performed concurrently in the computer

manages all of the message traffic that flows from the user to the application software to the computer

handles the allocation of resources and the assignment of tasks to various software programs

enables the user to carry out needed tasks with application software without worrying about the hardware interfaces


COMPARISON OF COMPARISON OF OPERATING SYSTEMSOPERATING SYSTEMS

Feature Mainframe Network PC Handheld

Number of simultaneous users

Multiple Multiple One One

Security Sophisticated Sophisticated Minimal/ user-enabled

Minimal/ user-enabled

Peripherals

Complex Numerous Few Few

Number of tasks

Many Many Many Few

Support Systems programmers

Networked-certified personnel

User Provider

Example OS390 Novell NOS Windows XP Windows Mobile


HOW THE OS WORKSHOW THE OS WORKSKernels handles requests from

application programs or hardware and determines the processing order.

Command interpreter (shell in UNIX operating systems) accepts commands from users and translates them for the kernel.

Graphical user interface (GUI) is used to communicate with the command interpreter.

Application program interface (API) allows the application program to make requests to the OS or another application.


LAYERS OF AN OSLAYERS OF AN OS


OS RESPONSIBILITIESOS RESPONSIBILITIES

The functions of the operating system are:

1. Starting the computer2. Managing hardware3. Controlling access to the computer4. Providing an interface for the user 5. Ensuring efficient use of the CPU6. Providing services to application

software© John Wiley & Sons Canada, Ltd. A-42

STARTING THE COMPUTERSTARTING THE COMPUTER


MANAGING HARDWAREMANAGING HARDWARE The operating system acts as a go-

between for the user, software, and hardware system.

Hardware management includes:◦ Input: operations like accepting data from

keyboard and instructions from a mouse◦ Output: sending information to the monitor

and to a printer◦ Transfer: of data, instructions, and

information between the CPU chip and internal memory and secondary storage

◦ Mainframes: hardware of multiple users◦ Network OS: controls the communications

between devices on the network


CONTROLLING ACCESSCONTROLLING ACCESSA mainframe or network operating

system must provide security to everyone's data, information, and programs against unwarranted intrusion.

Access controls exist that require the user to enter a password to use a PC.


EFFICIENT USE OF CPUEFFICIENT USE OF CPUA key task of the operating system is to ensure

that slow I/O does not hold up the CPU.One way to keep the I/O from interfering with

processing is to run programs concurrently. That is, the CPU processes part of one program, then part of another, and so on.

Multitasking handles multiple programs or tasks at the same time. The jobs are placed in a queue to be executed according to their level of priority.

PC network OS usually shift the processing burden from the central file server to local PCs.


EXAMPLE OF EXAMPLE OF MULTITASKINGMULTITASKING


PROVIDING SERVICES PROVIDING SERVICES TO TO APPLICATION SOFTWAREAPPLICATION SOFTWARE

Operating systems provide a number of services to application software, including:◦Running the application software and

ensuring that needed resources are available

◦Determining the order in which concurrent programs will be processed

◦File/disk management◦Memory management


APPLICATION SOFTWAREAPPLICATION SOFTWAREApplication software is designed to

help us accomplish work and tasks on the computer.

Application software for business comes in two primary forms:◦Commercial off-the-shelf software

(COTS) is ready to install and use without further modification on the part of the user.

◦Custom-developed software is developed by a company specifically for its own use.


POPULAR TYPES OF POPULAR TYPES OF COTS SOFTWARECOTS SOFTWAREWord processing programsSpreadsheets and accounting

softwareDatabase programsPresentation programsWeb browsers and other Internet-

related softwareSpecialized software


WORD PROCESSING WORD PROCESSING SOFTWARESOFTWARE

Word processing software is used to compose, edit, save, and print various types of documents.

Desktop publishing software combines word processing, graphics, and special page definition software to create professional documents.


SPREADSHEET SOFTWARESPREADSHEET SOFTWARE Spreadsheets are

an electronic table of rows and columns with the intersection of a row and a column being called a cell.

Cells are denoted by the column letter and row number.

Spreadsheets are widely used to carry out analyses.


Spreadsheet software accomplishes other tasks to help knowledge-enabled professionals, which include sorting data and creating charts to better understand data. © John Wiley & Sons Canada, Ltd. A-53

SPREADSHEET SOFTWARESPREADSHEET SOFTWARE

DATABASE SOFTWAREDATABASE SOFTWAREDatabase

software provides tools for organizing data into a form that allows for efficient search and retrieval.

Data related to a specific question of concern can be accessed using a query.


PRESENTATION SOFTWAREPRESENTATION SOFTWARE

Presentation software is used for creating presentations using text in many sizes and fonts, graphics, photos, and even audio and video files that can be used to inform an audience.

It is widely used for professional-quality presentations.


WEB BROWSER AND WEB BROWSER AND INTERNET SOFTWAREINTERNET SOFTWAREWeb browsers are used to access

information available on the World Wide Web.

Browsers have become the “jack of all trades” for Internet operations by enabling searches for web pages; communication using e-mail, instant messaging and chat rooms; and downloading files.


SPECIALIZED SOFTWARESPECIALIZED SOFTWARESpecialized software has been

developed to handle specific situations, be they financial, mathematical, engineering, or any number of other areas.


DEVELOPING DEVELOPING CUSTOMIZED SOFTWARECUSTOMIZED SOFTWARETo achieve a competitive advantage, a

company must often custom-develop software to meet its particular needs.

Computer programs are based on algorithms, which are detailed sequences of actions that, when followed, will accomplish some task.

The process of creating a computer program is called programming, which uses one of a variety of computer languages to communicate with the computer.


COMMONLY USED COMMONLY USED LANGUAGESLANGUAGES

Language Common Use

C (including C++ and C#)

Writing a wide variety of applications for PCs or network servers

Java Writing software for all types of computers; also for writing browser and server-side web software

PHP Writing web-based applications

SQL(Structured Query Language)

Writing queries to relational database management systems

VB.NET (Visual Basic .NET)

Writing software for PCs; also for writing browser and server-side web software (Microsoft’s version of Java)


OPEN SOURCE SOFTWAREOPEN SOURCE SOFTWAREIn open source software, the

programming code is freely available to any one who wishes to download it over the Internet.

The only requirement is that any change a programmer makes to the open-source code must also be made freely available to others.

Examples: Apache Web server software, the Linux operating system, mySQL database software

Proprietary software requires a license that must purchased by a company and the source code is not available to anyone outside of the company.


RECAPRECAP1. What elements affect the processing

capability of hardware?2. What types of input, output, and

storage hardware should business professionals keep current with?

3. Why is the operating system so important to the use of all types of computers?

4. How do business professionals obtain and use application software?


tech guide a the details of it hardware and software © john wiley & sons canada, ltd.a-1

Documents

electronic devices

binary digit

hardware devicescost

storage devices

original code

information interchange

convenient number system

information needs