Tech Guide A Tech Guide A The Details of IT The Details of IT
Hardware and SoftwareHardware and Software
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What We Will Cover
• An Overview of Hardware
• Hardware Devices
• Operating Software
• Application Software
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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.
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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.
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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.
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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
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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
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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.
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CHARACTER ENCODINGCHARACTER ENCODING
Binary codes represent letters and numbers through character encoding.
Character encoding permits a specific combination of bits to represent each character.
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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
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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
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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).
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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.
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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.
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KEY CPU COMPONENTSKEY CPU COMPONENTSControl UnitArithmetic Logic Unit
(ALU)Floating Point Unit
(FPU)Decode UnitCache Memory Prefetch UnitRegistersClockBusInstruction Set
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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.
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DATA AND INSTRUCTION DATA AND INSTRUCTION FLOW IN THE CPUFLOW IN THE CPU
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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
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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).
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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.
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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.
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HARDWARE DEVICESHARDWARE DEVICES
Input hardware: Serves as the interface for
entering data and information Converts data and information
into binary form
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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
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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
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OTHER INPUT DEVICESOTHER INPUT DEVICESSelecting input devices
◦Ergonomic considerations◦Environmental conditions◦Performance
Accuracy Resolution Tracking Speed
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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
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TYPES OF OUTPUT TYPES OF OUTPUT HARDWAREHARDWARE
Display devices: LCD, touch screens Printers: laser, inkjet, thermal,
multifunctional devicePlotters: flatbed, drum, electrostatic
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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
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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.
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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.
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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).
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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
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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.
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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
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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.
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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
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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
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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.
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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
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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
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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.
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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.
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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
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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.
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POPULAR TYPES OF POPULAR TYPES OF COTS SOFTWARECOTS SOFTWAREWord processing programsSpreadsheets and accounting
softwareDatabase programsPresentation programsWeb browsers and other Internet-
related softwareSpecialized software
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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.
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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.
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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.
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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.
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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.
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SPECIALIZED SOFTWARESPECIALIZED SOFTWARESpecialized software has been
developed to handle specific situations, be they financial, mathematical, engineering, or any number of other areas.
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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.
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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)
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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.
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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?
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