```Tech Guide A
The Details of IT
Hardware and Software
A-1
What We Will Cover
• An Overview of Hardware
•
Hardware Devices
•
Operating Software
• Application Software
A-2
AN OVERVIEW OF HARDWARE
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.

A-3
EVALUATING HARDWARE
DEVICES




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.
A-4
EVALUATING HARDWARE
DEVICES



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.
A-5
TRANSISTORS
The 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

A-6
BINARY 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

A-7
RELATING BINARY AND
DECIMAL VALUES
23410 = 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.
A-8
CHARACTER ENCODING
Binary codes represent letters
and numbers through character
encoding.
 Character encoding permits
a specific combination of bits to
represent each character.

A-9
ENCODING SCHEMES
Extended 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

A-10
COMPARISON OF
ENCODING SCHEMES
Character
EBCDIC
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
A-11
MACHINE 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).
A-12
IMPORTANT POWERS OF TWO
Because computers use the binary number
system, all measures are in powers of two.
Power Decimal Value
of 2
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)
A-13
PROCESSING HARDWARE
The 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.

A-14
KEY CPU COMPONENTS
Control Unit
Arithmetic Logic Unit
(ALU)
 Floating Point Unit (FPU)
 Decode Unit
 Cache Memory
 Prefetch Unit
 Registers
 Clock
 Bus
 Instruction Set


A-15
CPU FUNCTIONS
1. 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.
A-16
DATA AND INSTRUCTION
FLOW IN THE CPU
A-17
CPU 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
A-18
INTERNAL MEMORY: ROM



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).
A-19
INTERNAL MEMORY: RAM

Random access memory (RAM): the
main short-term memory in a computer
◦
◦
◦
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
A-20
TYPES OF RAM
Dynamic 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.

A-21
HARDWARE DEVICES
Input hardware:
 Serves as the interface for entering data
and information
 Converts data and information into
binary form
A-22
TYPES OF INPUT HARDWARE






Keyboard
Pointing 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
Audio input: microphone
Optical input: digital camera, WebCam
Sensors
A-23
INPUT DEVICES
A-24
OTHER INPUT DEVICES

Audio 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
A-25
OTHER INPUT DEVICES

Selecting input devices
◦ Ergonomic considerations
◦ Environmental conditions
◦ Performance




Accuracy
Resolution
Tracking
Speed
A-26
OUTPUT HARDWARE
COMPONENTS
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
A-27
TYPES OF OUTPUT HARDWARE
Display devices: LCD, touch screens
 Printers: laser, inkjet, thermal,
multifunctional device
 Plotters: flatbed, drum, electrostatic

A-28
OUTPUT HARDWARE
DEVICES: DISPLAY

LCD 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
A-29
DISPLAY DEVICE PERFORMANCE
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.

A-30
TOUCH SCREEN DEVICES
A 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.

A-31
PRINTED OUTPUT DEVICES
A-32
STORAGE DEVICES
Storage 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).

A-33
TYPES OF STORAGE DEVICES
Magnetic disks: diskette, hard disk drive,
high capacity diskettes, tape
 Optical disks: CD-ROM (-R, -RW), DVD
(-R, -RW, -HD, -Blu-ray)
 Chip-based storage: USB flash drives

A-34
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.

A-35
STORAGE HARDWARE

Flash 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
A-36
OPERATING SOFTWARE
REVIEW OF SOFTWARE
Software 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.
A-37
OVERVIEW OF THE
OPERATING SYSTEM
The operating system (OS):
 is a collection of software programs that
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
A-38
COMPARISON OF
OPERATING 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
Many
Many
Many
Few
Support
Systems
programmers
Networkedcertified personnel
User
Provider
Example
OS390
Novell NOS
Windows XP
Windows
Mobile
A-39
HOW THE OS WORKS




Kernels 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.
A-40
LAYERS OF AN OS
A-41
OS RESPONSIBILITIES
The functions of the operating system are:
1. Starting the computer
2. Managing hardware
4. Providing an interface for the user
5. Ensuring efficient use of the CPU
6. Providing services to application
software
A-42
STARTING THE COMPUTER
A-43
MANAGING 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
A-44
CONTROLLING ACCESS
A 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.

A-45
EFFICIENT USE OF CPU
A 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.
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.

A-46
A-47
PROVIDING SERVICES TO
APPLICATION 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
A-48
APPLICATION SOFTWARE
Application 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.
A-49
POPULAR TYPES OF
COTS SOFTWARE
Word processing programs
 Database programs
 Presentation programs
 Web browsers and other Internet-related
software
 Specialized software

A-50
WORD PROCESSING
SOFTWARE
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.

A-51



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.
used to carry out
analyses.
A-52

software
accomplishes
help knowledgeenabled
professionals,
which include
sorting data and
creating charts to
better understand
data.
A-53
DATABASE SOFTWARE
Database 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.

A-54
PRESENTATION 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.
A-55
WEB BROWSER AND
INTERNET SOFTWARE
Web 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

A-56
SPECIALIZED SOFTWARE

Specialized software has been developed
to handle specific situations, be they
financial, mathematical, engineering, or any
number of other areas.
A-57
DEVELOPING CUSTOMIZED
SOFTWARE



To 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.
A-58
COMMONLY USED
LANGUAGES
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)
A-59
OPEN SOURCE SOFTWARE
In open source software, the programming
code is freely available to any one who wishes to
 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.

A-60
RECAP
What elements affect the processing
capability of hardware?
2. What types of input, output, and storage
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?
1.
A-61
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