1. Chapter 2 Hardware and Software

2. Why Learn About Hardware and Software?
Hardware can improve productivity, increase revenue, reduce costs, and provide better service
Managers are expected to know about hardware
To help define business needs
To ask questions and evaluate options when buying equipment
Software is indispensable for any computer system
Systems software needed for input, calculations, and output
Application software aids in productivity

3. Hardware Components Central processing unit (CPU)
Arithmetic/logic unit (ALU): performs calculations and makes logical comparisons
Control unit: accesses, decodes and coordinates data in CPU and other devices
Primary memory: holds program instructions and data for processing
Secondary storage: more permanent storage
Input and output devices
Communications devices

4. Figure 2.1: Hardware Components

5. Processing and Memory Devices: Power, Speed, and Capacity
System unit
Houses the components responsible for processing (the CPU and memory)
All other computer system devices are linked either directly or indirectly into the system unit housing

6. Processing Characteristics and Functions
Clock speed: series of electronic pulses produced at a predetermined rate that affects machine cycle time
Clock speed is often measured in megahertz (MHz), or millions of cycles per second
Clock speed for personal computers is in the multiple gigahertz (GHz), or billions of cycles per second, range

7. Processing Characteristics and Functions
Physical characteristics of the CPU
Digital circuits on chips
To turn a digital circuit on or off, electrical current flows through silicon

8. Memory Characteristics and Functions: Storage Capacity
Table 2.1: Units for Measuring Computer Storage

9. Memory Characteristics and Functions: Types of Memory
Random access memory (RAM)
Temporary
Volatile
Read-only memory (ROM)
Usually nonvolatile

10. Multiprocessing
Multiprocessing: simultaneous execution of two or more instructions
Multicore microprocessor: shares workload among two or more independent processors in a single computer
Parallel processing: links several processors to operate at the same time, or in parallel
Grid computing: collection of computers working to solve a common problem

11. Secondary Storage and Input and Output Devices
Also called permanent storage
Nonvolatile
Greater capacity and greater economy than memory
Access methods, storage capacities, and portability required are determined by the information system’s objectives

12. Access Methods
Sequential access: data must be accessed in the order in which it is stored
Sequential access storage devices (SASDs)
Direct access: data can be retrieved in any order
Direct access storage devices (DASDs)

13. Secondary Storage Devices
Magnetic tapes
Secondary storage used primarily for backups
Magnetic disks
Direct access secondary storage, e.g., hard disk
RAID
Stores extra bits so that data can be reconstructed if system fails
SAN
Provides high-speed connections between data storage devices and computers over a network
Optical disks
Direct access optical disc, e.g., CD-ROM
Digital video disk (DVD)
Stores several gigabytes of data
Flash memory
Nonvolatile silicon computer chip

14. Input Devices Personal computer input devices
Keyboard, mouse
Speech-recognition technology
Input devices that recognize human speech
Digital cameras
Input device used with PC to record/store images in digital form
Terminals
Input and display devices that perform data entry and input at the same time
Touch-sensitive screens
Allow display screens to act as input devices as well as output devices
Bar-code scanners
Employs a laser scanner to read a bar-coded label
Magnetic ink character recognition (MICR) devices
Code data on banking forms, such as checks
Pen input devices
Activate a command, enter handwritten notes, and draw objects
Radio Frequency Identification (RFID)
Employs a microchip with an antenna to broadcast its unique identifier and location to a receiver

15. Output Devices Printers and plotters: hard copy output
Display monitors (CRTs)
Output quality measured by number of pixels and dot pitch
Liquid crystal displays (LCDs)
Easier on eyes, use less electricity, take up less space than CRTs
Organic light-emitting diodes (OLEDs)
Directly emits light rather than using backlight
Sharper colors and thinner displays
Printers and plotters: hard copy output
Printers: laser, inkjet
Plotters: used for general design work
Digital audio player
Stores, organizes, and plays digital music files

16. Table 2.3: Types of Computer Systems
Computer System Types
Table 2.3: Types of Computer Systems

17. Overview of Software
Computer programs: sequences of instructions for the computer
Documentation: describes program functions
Systems software: coordinates the activities of hardware and programs
Application software: helps users solve particular problems

18. Supporting Individual, Group, and Organizational Goals
Table 2.4: Classifying Software by Type and Sphere of Influence

19. Systems Software
Controlling operations of computer hardware is one of the most critical functions of systems software
Also supports application programs’ problem-solving capabilities
Different types of systems software include:
Operating systems
Utility programs

20. Operating Systems Combinations of OSs, computers, and users:
Operating system (OS): programs that control the hardware and interface with applications
Common hardware functions
Get input (e.g., keyboard)
Retrieve data from disks and store data on disks
Display information on a monitor or printer
Combinations of OSs, computers, and users:
Single computer with a single user
Single computer with multiple users
Multiple computers
Special-purpose computers

21. Figure 2.8: The Role of Systems Software
Operating Systems
Figure 2.8: The Role of Systems Software

22. Operating Systems Common hardware functions
Activities performed by the operating system
Perform common computer hardware functions
Provide a user interface and input/output management
Provide a degree of hardware independence
Manage system memory
Manage processing tasks
Provide networking capability
Control access to system resources
Manage files
Hardware independence
Application program interface (API): allows applications to make use of the operating system
Memory management
Converts a user’s request for data or instructions to the physical location where the data or instructions are stored
Common hardware functions
Get input from keyboard or some other input device
Retrieve data from disks
Store data on disks
Display information on a monitor or printer
User interface
Allows individuals to access and command the computer system
Command-based user interface: uses text commands
Graphical user interface (GUI): uses icons and menus to send commands to the computer system

23. Operating Systems
Figure 2.9: Application Program Interface Links Application Software to the Operating System

24. Operating Systems Processing tasks
Multitasking: more than one program running at the same time
Time-sharing: more than one person using a computer system at the same time
Scalability: ability to handle an increasing number of concurrent users smoothly
Networking capability: aids users in connecting to a computer network

25. Operating Systems Access to system resources File management
Protection against unauthorized access
Logins and passwords
File management
Ensures that files in secondary storage are:
Available when needed
Protected from access by unauthorized users

26. Application Software
Give users the ability to solve problems and perform specific tasks
Interact with systems software; systems software then directs the hardware to perform tasks

27. Types and Functions of Application Software

28. Personal Application Software
Serves the needs of an individual user
Includes personal productivity software
Enables users to improve their personal effectiveness

29. Personal Application Software
Table 2.7: Examples of Personal Productivity Software (continued)

30. Workgroup Application Software
Workgroup application software: support teamwork, whether people are in the same location or dispersed around the world
Groupware: software that helps groups of people work together more efficiently and effectively

31. Enterprise Application Software
Software that benefits an entire organization
Enterprise resource planning (ERP) software: programs that manage a company’s vital business operations for an entire multisite, global organization

32. Programming Languages
Table 2.11: The Evolution of Programming Languages

33. Software Issues and Trends
Software issues and trends receiving increasing attention
Software bugs
Copyrights and licenses
Software upgrades
Global software support