Information Systems: Creating Business Value

by Mark Huber, Craig Piercy, and Patrick McKeown

Field Guide A: Details of IT Hardware

What We Will Cover:

Evaluating Hardware Devices

The Electronics of Hardware

Processing Hardware

Internal Memory

Input Hardware Devices

Output Hardware Devices

Hardware Storage

Student ROI (Return on Investment)

Your investment of time and effort in this course will result in your being able to answer these questions:

1. What factors should knowledge workers consider, to optimize their use of an IT device?

2. How do the electronic components of IT hardware allow the transmission and storage of data?

3. What elements affect the processing capability of hardware?4. How does internal memory work to enable processing of

data into information?5. How can the type of input hardware help to make knowledge

work more productive?6. Why should knowledge workers keep current about new

developments in output hardware?

Review of Hardware

Recall: Hardware is the physical component of IT Hardware consists of the electro-mechanical

devices with which we can work with information

Evaluating Hardware Devices

Criteria of choice – the characteristics that we use to differentiate between various options. For most hardware devices these can include:

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 in the 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 to be accurate.

Speed - We want to work as quickly and efficiently as possible. Portability – Many times we want our devices to be portable. (Actually,

we want our ability to work with information to be portable.)

Can you think of other criteria?

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, for example:

On = 1

Off = 0

Binary Numbers

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

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

8 bits = 1 byte = 1 character

Relating Binary and Decimal Values

23410 = 20010 + 3010 + 410 = 2*102 + 2*101 + 2*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 (an example is given in Table A-1)

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

Important Powers of Two

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 Hardware

The microprocessor that 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 Components

Control Unit Arithmetic Logic Unit (ALU) Floating Point Unit (FPU) Cache Memory and Registers Clock Bus Instruction Set

Internal 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 startup processes (booting up).

This small set of instructions is known as the BIOS (Basic Input/Output System).

Internal 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 may be addressed.

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) - Faster and less volatile than DRAM, but much more expensive.

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

Input Hardware Components

Input hardware: Serves as the interface for entering data and

information. Converts data and information into binary

form. Criteria of choice: matches data type,

accurate, efficient, ergonomic, reliable, good value.

Types of Input Hardware

Keyboard Pointing devices: mouse, light pen, joystick,

touch pad, trackball Scanning devices: flatbed scanner, barcode

reader, OCR, MICR, biometric scanner Audio input: microphone Optical input: digital camera, webcam Sensors

Keyboard Data Entry

Input Devices

Bar Code Readers

Bar code reader: A device that reads a printed horizontal strip of vertical bars. The bar widths and spaces between the bars vary in a standard way to represent a group of decimal digits using the Universal Product Code (UPC).

Output Hardware Components

Output hardware: Serves as the interface for

receiving data and information Converts data and information

from binary form into more useful form for humans

Criteria of choice: high quality, matches intended use, accurate, efficient, ergonomic, reliable, good value

Display System

Types of Output Hardware

Display devices: CRT, LCD, Touch-screen Printers: laser, inkjet, thermal, dot-matrix Plotters: flatbed, drum, electrostatic Audio output: speakers, MIDI Optical input: digital camera, webcam Actuators

Output Devices

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 newer tablet PCs frequently use touch screens.

Storage Devices

Storage - 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)

Criteria of choice: capacity, access speed, portability

Types of Storage Devices

Hard Disk Removable Magnetic Storage: Diskette, High

Capacity Diskettes, Tape Removable Optical Storage: CD-ROM, -R, -

RW; DVD, DVD-R Other: USB Flash Drives, Hard Disk Cards,

Magnetic strips, smart cards

Storage Devices

Other Hardware Considerations

Power – power supply, surge suppressor, UPS

Cables and connectors – parallel, serial, USB

Slots and Cards