1 Chapter 2 Hardware and Software
2 Principles and Learning Objectives: Hardware SelectionComputer hardware must be carefully selected to meet the evolving needs of the organization and of its supporting information systems Identify and discuss the role of the essential hardware components of a computer system Identify the characteristics of and discuss the usage of various classes of single-user and multiuser computer systems
3 Principles and Learning Objectives: Green ComputingThe computer hardware industry and users are implementing green computing designs and products Define the term green computing and identify the primary goals of this program Identify several benefits of green computing initiatives that have been broadly adopted
4 Principles and Learning Objectives: Implementing a Data CenterThe computer hardware industry and users are implementing green computing designs and products Identify some of the challenges and tradeoffs that must be considered in implementing a data center
5 Principles and Learning Objectives: Critical Need for SoftwareSystems and application software are critical in helping individuals and organizations achieve their goals Identify and briefly describe the functions of the two basic kinds of software Outline the role of the operating system and identify the features of several popular operating systems
6 Principles and Learning Objectives: Meeting Business NeedsOrganizations use off-the-shelf application software for common business needs and proprietary application software to meet unique business needs and provide a competitive advantage Discuss how application software can support personal, workgroup, and enterprise business objectives
7 Principles and Learning Objectives: Providing a Competitive AdvantageOrganizations use off-the-shelf application software for common business needs and proprietary application software to meet unique business needs and provide a competitive advantage Identify three basic approaches to developing application software and discuss the pros and cons of each
8 Principles and Learning Objectives: Programming LanguagesOrganizations should choose programming languages with functional characteristics that are appropriate for the task at hand and well suited to the skills and experience of the programming staff Outline the overall evolution and importance of programming languages and clearly differentiate among the generations of programming languages
9 Principles and Learning Objectives: Trends and IssuesThe software industry continues to undergo constant change; users need to be aware of recent trends and issues to be effective in their business and personal life Identify several key software issues and trends that have an impact on organizations and individuals
10 Why Learn About Hardware and Software?Organizations invest in computer hardware and software to improve worker productivity, increase revenue, reduce costs, and provide better customer service Managers in all career fields should know enough about their business’ needs to be able to ask tough questions of those recommending the hardware and software to meet those needs
11 Computer Systems: Integrating the Power of TechnologyPeople involved in selecting their organization’s computer hardware must clearly business requirements so that they can make informed acquisition decisions Choosing the right computer hardware requires understanding its relationship to the information systems and the current and future needs of the organization
12 Computer Systems: Hardware ComponentsHardware components include devices that perform: Input Processing Data storage Output
13 Hardware Components FIGURE 2.1 Hardware componentsThese components include the input devices, output devices, ports, bus, primary and secondary storage devices, and the central processing unit (CPU). The control unit, the arithmetic/logic unit (ALU), and the register storage areas constitute the CPU.
14 Central Processing Unit (CPU) ComponentsArithmetic/logic unit (ALU): performs mathematical calculations and makes logical comparisons Control unit Sequentially accesses program instructions Decodes the instructions Coordinates the flow of data in and out of the ALU, registers, primary storage, as well as secondary storage and various output devices
15 System Hardware Components: Registers, Buses, and MemoryRegisters: high-speed storage areas used to temporarily hold small units of program instructions and data Bus: a set of physical connections (cables, printed circuits, etc.) that can be shared by multiple hardware components so they can communicate with one another Primary storage (main memory or memory) works closely with the CPU
16 Processing and Memory Devices: Power, Speed, and CapacityThe system unit houses the components responsible for processing (the CPU and primary storage) All other computer system devices are linked either directly or indirectly into the system unit housing
17 Processing Characteristics and Functions: Clock SpeedA series of electronic pulses produced at a predetermined rate that affects machine cycle time Often measured in: Gigahertz (GHz): billions of cycles per second
18 Memory Characteristics and FunctionsProvides the CPU with a working storage area for programs and data Rapidly provides data and instructions to the CPU Storage capacity Byte (B): eight bits that together represent a single character of data
19 Table 2.1 Computer Storage UnitsName Abbreviation Number of Bytes Byte B 1 Kilobyte KB 1,000 Megabyte MB 1,0002 Gigabyte GB 1,0003 Terabyte TB 1,0004 Petabyte PB 1,0005 Exabyte EB 1,0006 Zettabyte ZB 1,0007 Yottabyte YB 1,0008 TABLE 2.1 Computer storage units
20 Types of Memory Random access memory (RAM) is a form of memory in which instructions or data can be temporarily stored Read-only memory (ROM) is nonvolatile providing permanent storage for data and instructions that do not change
21 Multiprocessing Multiprocessing: the simultaneous execution of two or more instructions A multicore microprocessor combines two or more independent processors into a single computer When selecting a CPU, organizations must balance the benefits of processing speed with energy requirements, size, and cost
22 Parallel Computing and Grid ComputingParallel computing: the simultaneous execution of the same task on multiple processors to obtain results faster Massively parallel processing: hundreds or thousands of processors linked to operate at the same time Grid computing: a collection of computers (several owners) working in a coordinated manner to solve a common problem
23 Secondary Storage Devices that store large amounts of data, instructions, and information more permanently than allowed with memory Advantages over memory Nonvolatility Greater capacity Greater economy
24 Access Methods Sequential access Direct accessData must be retrieved in the order in which it is stored Devices used are called sequential access storage devices (SASDs) Direct access Records can be retrieved in any order Devices used are called direct access storage devices (DASDs)
25 Secondary Storage DevicesAre not directly accessible by the CPU Most common forms Magnetic Optical Solid state
26 Magnetic Secondary Storage DevicesMagnetic tapes: a type of sequential secondary storage medium Primarily for storing backups of critical organizational data Hard disk drive (HDD): a direct access storage device; consists of rapidly rotating disks coated with magnetic material
27 Magnetic Secondary Storage Devices (cont’d.)Redundant array of independent/inexpensive disks (RAID): a method of storing data that generates extra bits of data from existing data Disk mirroring: a process of storing data that provides an exact copy that protects users fully in the event of data loss Virtual tape: a storage device for less frequently needed data
28 Storage Area Network (SAN)FIGURE 2.4 Storage area network A SAN provides high-speed connections among data-storage devices and computers over a network.
29 Optical Discs Common types of optical storage devicesCompact disc read-only memory (CD-ROM) Digital video disc (DVD) Blu-ray high-definition video disk Holographic Versatile Disc (HVD)
30 Solid State Secondary Storage Devices (SSDs)Store data in memory chips rather than magnetic or optical media Advantages Require less power and provide faster access than magnetic data storage devices Have no moving parts, so they are less fragile than hard disk drives A universal serial bus (USB) flash drive is a common SSD
31 Storage as a Service A data storage model where a data storage service provider rents space to individuals and organizations Rented data storage is accessed via the Internet Cloud-based storage services Amazon’s Elastic Compute Cloud, Apple iCloud, Dropbox, Google Drive, Microsoft SkyDrive, and Mozy
32 Input Devices Devices for general types of dataPersonal computer input devices Speech-recognition technology Motion-sensing devices Digital cameras Scanning devices Optical data readers Magnetic ink character recognition (MICR) devices
33 MICR Device FIGURE 2.7 MICR deviceMagnetic ink character recognition technology codes data on the bottom of a check or other form using special magnetic ink, which is readable by people and computers. For an example, look at the bottom of a bank check.
34 Input Devices for General Types of Data (cont’d.)Magnetic stripe cards Smart cards Contactless payment cards Point-of-sale (POS) devices Bar-code scanners Radio frequency identification (RFID) Pen input devices Touch-sensitive screens
35 RFID Tag FIGURE 2.9 RFID tagAn RFID tag is small compared to current bar-code labels used to identify items.
36 Types of Output Devices: Display ScreensFlat-panel display screens Liquid crystal display (LCD) Light-emitting diode (LED) Organic light-emitting diode (OLED) Plasma
37 Table 2.3 Various Types of Flat-Panel DisplaysDescription Noteworthy Feature Liquid crystal display (LCD) Uses several layers of charged liquid crystals placed between clear plates that are lit from behind by a fluorescent light to create light and images The viewing angle tends to be worse than that of plasma displays Light-emitting diode (LED) An LCD display that uses light- emitting diodes (LEDs) as backlight on the screen rather than a fluorescent lamp Provides better contrast and lower energy consumption than LCDs Organic light-emitting diode (OLED) Functions by exciting organic compounds with electric current to produce bright, sharp images Does not employ a backlight, which enables improved contrast and lower power consumption than LCD and LED displays Plasma Uses electricity to excite gas atoms to light up appropriate phosphors on the screen to emit light and color Performs well in dark conditions and not as well in well-lit rooms TABLE 2.3 Various types of flat-panel displays
38 Output Devices: Printers and PlottersPrinters and plotters produce hard copy Laser printers and inkjet printers Multi-function printers 3D printers Plotters are used for general design work
39 Output Devices: Electronic BooksAn electronic book (e-book) is the digital media equivalent of a conventional printed book
40 Computer System Types Computer systems can range from desktop or portable computers to massive supercomputers Two major groups of general-purpose computers Single-user computers with portable and nonportable options Multiple-user computers
41 Table 2.4 Single-User Computers: Portable ComputersFactor Handheld Laptop Notebook/Ultrabook Tablet Cost $150–$3,000 $300–$1,200 $300–$800 $350–$700 Weight (pounds) <0.5 <7 <3 <2 Screen size (inches) 2–4 <17 <13 Typical use Data collection, organize personal data Improve worker productivity Sufficient processing power to run nearly every business application Capture data at the point of contact, read , surf the Internet, read e- books, view photos, play games, listen to music, and watch video files TA BLE 2.4 Types of computer systems Single-user computer systems can be divided into two groups: portable computers and nonportable computers.
42 Table 2.4 Single-User Computers: Nonportable ComputersFactor Thin Client Desktop Nettop Workstation Cost $200–$500 $500–$2,500 $150–$350 $1,500–$9,500 Weight (pounds) <3 20–30 <5 <20–35 Typical use Enter data and access applications via the Internet Improve worker productivity Replace desktop with small, low- cost, low- energy computer Perform engineering, CAD, and software development TA BLE 2.4 Types of computer systems (cont’d.) Single-user computer systems can be divided into two groups: portable computers and nonportable computers.
43 Portable Computers Handheld computer: a compact computing deviceTypically includes a display screen with stylus or touch screen input along with a compact keyboard or numeric keypad Applicable as POS devices Rugged versions are available for military applications
44 Portable Single-User Computers (cont’d.)Laptop computers are designed for use by mobile users Notebook and ultrabook computers are smaller than laptop computers Tablet computers are portable, lightweight computers with or without a keyboard
45 Nonportable Single-User ComputersA thin client is a low-cost, centrally managed computer with no internal or external attached drives for storage Desktop computers are single-user computer systems that are highly versatile
46 Nonportable Single-User Computers (cont’d.)A nettop computer is an inexpensive desktop computer Smaller, lighter, and consumes much less power than a traditional desktop computer Workstations are more powerful than personal computers but still small enough to fit on a desktop
47 Table 2.4 Multiple-User ComputersFactor Server Mainframe Supercomputer Cost >$500 >$75,000 >$250,000 Weight (pounds) >25 >100 Typical use Execute network and Internet applications Execute computing tasks for large organizations and provide massive data storage Run scientific applications; perform intensive number crunching TA BLE 2.4 Types of computer systems (cont’d.) Multiple-user computer systems include servers, mainframes, and supercomputers.
48 Multiple-User Computer SystemsA server is employed by many users to perform a specific task, such as running network or Internet applications Server systems consist of multiuser computers, including supercomputers, mainframes, and other servers Blade server: a server that houses many individual computer motherboards
49 Multiple-User Computer Systems: Mainframes and SupercomputersMainframe computer: a large, powerful computer shared by hundreds of concurrent users connected to the machine over a network Supercomputers: the most powerful computers with the fastest processing speed and highest performance
50 Data Centers Data center: a climate-and-access-controlled building or a set of buildings that houses the computer hardware that delivers an organization’s data and information services
51 Data Centers: Reasons for Their GrowthRapid growth in the demand of additional computing capacity Need for additional data storage capacity Consolidation of organizations’ data centers from many locations to a few locations
52 Data Centers: Construction ConsiderationsMore efficient operation and reduced energy for processing and cooling Modular design Location: areas with milder climates and lower energy rates and land costs Ability to absorb the impact of a disaster (e.g., hurricane, earthquake, terrorism attack, or war) and quickly restore services
53 Modular Data Center FIGURE 2.17 Modular data centerEach module in a modular data center has a server that is cooled efficiently by water and by fans that require much less energy than air conditioning units.
54 Green Computing A program concerned with the efficient and environmentally responsible design, manufacture, operation, and disposal of IS-related products
55 Green Computing: GoalsReduce the use of hazardous material Allow companies to lower their power-related costs Enable safe disposal or recycling of equipment
56 Electronic Product Environmental Assessment Tool (EPEAT)A system that enables purchasers to evaluate, compare, and select electronic products based on a total of 51 environmental criteria Tier Number of Required Criteria That Must Be Met Number of Optional Criteria That Must Be Met Bronze All 23 None Silver At least 50% Gold At least 75% TABLE 3.7 EPEAT product tiers
57 An Overview of SoftwareComputer programs: sequences of instructions for the computer Documentation: text that describes program functions to help the user operate the computer system Types of software Systems software Application software
58 Systems Software The set of programs that coordinates the activities and functions of hardware and other programs Each type of systems software is designed for a specific CPU and class of hardware
59 Application Software Helps users solve particular problemsIn most cases, resides on the computer’s hard disk Can be stored on CDs, DVDs, or USB flash drives An increasing amount of application is available on the Web as a rich Internet application (RIA)
60 Supporting Individual, Group, and Organizational GoalsSphere of influence: the scope of problems and opportunities addressed by a particular organization Personal sphere of influence Serves the needs of an individual user Personal productivity software Enables users to improve their personal effectiveness
61 Supporting Individual, Group, and Organizational Goals (cont’d.)Workgroup: two or more people working together to achieve a common goal Workgroup sphere of influence Helps workgroup members attain their common goals Enterprise sphere of influence Serves the needs of the firm in its interaction with its environment
62 Table 2.6 Software Supporting Individuals, Workgroups, and EnterprisesPersonal Workgroup Enterprise Systems software Smartphone, tablet computer, personal computer, and workstation operating systems Network operating systems Server and mainframe operating systems Application software Word processing, spreadsheet, database, and graphics Electronic mail, group scheduling, shared work, and collaboration General ledger, order entry, payroll, and human resources TABLE 2.6 Software supporting individuals, workgroups, and enterprises
63 Installing and Removing SoftwareSoftware must be installed on a computer before the software can be used Removing software using an add/remove software utility helps ensure that all elements of unwanted software are removed
64 Systems Software Controls the operations of computer hardwareSupports the application programs’ problem-solving capabilities Types of systems software Operating systems Utility programs Middleware
65 Operating Systems A set of programs that controls computer hardware and acts as an interface with application programs
66 Operating Systems: Combinations of OSs, Computers, and UsersSingle computer with a single user Single computer with multiple simultaneous users Multiple computers with multiple users Special-purpose computers
67 Role of Operating SystemsFIGURE 2.19 Role of operating systems The role of the operating system is to act as an interface between application software and hardware.
68 Operating System ActivitiesControlling common computer hardware functions Providing a user interface and input/output management Providing a degree of hardware independence Managing system memory Managing processing tasks
69 Operating System Activities (cont’d.)Providing networking capability Controlling access to system resources Managing files
70 Operating Systems: Common Hardware FunctionsGet input from keyboard or another input device Retrieve data from disks Store data on disks Display information on a monitor or printer
71 Operating Systems: User Interface and Input/Output ManagementA user interface allows individuals to access and interact with the computer system A command-based user interface requires text commands A graphical user interface (GUI) The user interacts with icons and menus to send commands to the computer system
72 Operating Systems: Hardware IndependenceApplication program interface (API): An interface that allows applications to make use of the operating system Hardware independence allows software development without understanding the inner workings of the operating system
73 Operating Systems: Memory ManagementAllows the computer to execute program instructions effectively and to speed processing Virtual memory: hard disk space is allocated to supplement the immediate, functional memory capacity of RAM Paging
74 Operating Systems: Processing TasksFive basic task management techniques Multiuser: allows two or more users to run programs at the same time on one computer Multiprocessing: supports running a program on more than one CPU Multitasking: allows more than one program to run concurrently Multithreading Real time
75 Processing Tasks: Five Basic Task Management Techniques (cont’d.)Multithreading: allows different threads of a single program to run concurrently A thread is a set of instructions within an application that s independent of other threads Real time: responds to input instantly
76 Operating Systems: Networking CapabilityAllows computers in a network to send and receive data and share computing resources
77 Operating Systems: Access to System Resources and SecurityProvides protection against unauthorized access to the users’ data and programs Establishes a logon procedure May control access to specific system resources Tracks who is using the system, length of use, and attempted security breaches
78 Operating Systems: File ManagementEnsures that files in secondary storage are available when needed Protects files from access by unauthorized users
79 Table 2.7 Operating Systems Serving Three Spheres of InfluencePersonal Workgroup Enterprise Microsoft Windows Microsoft Windows Server Mac OS X, iOS Mac OS X Server Linux Google Android, Chrome OS HP webOS UNIX IBM i and z/OS HP-UX TABLE 2.7 Operating systems serving three spheres of influence
80 Current Operating SystemsMicrosoft PC operating systems Windows XP Windows Vista Windows 7 Windows 8 Apple computer operating systems OS X 10.9 Mavericks Mac users can dual boot to run either Windows or Mac OS X
81 Current Operating Systems: LinuxOpen-source operating system Three of the most widely used distributions come from software companies: RedHat SUSE Canonical
82 Current Operating Systems: GoogleAndroid: an operating system for mobile devices Chrome OS Linux-based operating system designed for netbooks and nettops Designed to run on inexpensive low-power computers Chromium OS: an open-source version of Chrome OS
83 Workgroup Operating SystemsWindows Server provides: A powerful Web server management system Virtualization tools that allow various operating systems to run on a single server Advanced security features Robust administrative support UNIX can be used on many computer system types and platforms
84 Workgroup Operating Systems (cont’d.)Red Hat Enterprise Linux Server can manage a cluster of several servers Mac OS X Server includes Support for 64-bit processing Several server functions and features for easy management of network and Internet services HP-UX is a robust UNIX-based OS from Hewlett-Packard
85 Enterprise Operating SystemsExamples of mainframe OSs z/OS: IBM’s first 64-bit enterprise OS HP-UX from Hewlett-Packard Linux
86 Mobile Operating SystemsSmartphones now employ full-fledged personal computer operating systems Google Android Apple iOS Microsoft Windows Phone
87 Table 2.8 Comparison of Smartphone Operating SystemsWorldwide Market Share of Sales during 2Q 2013 Estimated Total Number of Applications Mid-2013 Estimated Rate of Increase in Number of New Applications Google Android 56.5% >1,000,000 800/day Apple iPhone OS 39.6% 900,000 600/day Microsoft Windows Mobile 3.3% 145,000 130/day Blackberry Limited, Blackberry 2.9% 120,000 NA TABLE 2.8 Comparison of smartphone operating systems Sources: Etherington, Darrell, “Android Nears 80% Market Share in Global Smartphone Shipments, As iOS And BlackBerry Share Slides, per IDC,” Tech Crunch, August 7, 2013, Cunningham, Andrew, “One Developer Makes over 47,000 of BlackBerry 10’s 120,000 Apps,” Ars Technica, August 21, 2013, Rowinski, Dan, ReadWrite, January 08, 2013, Google Play Will Beat Apple App Store to 1,000,000 Apps,
88 Embedded Operating SystemsEmbedded system: a computer system (including a processor) implanted in and dedicated to the control of another device Popular OSs for embedded systems Windows embedded Proprietary Linux-based systems: Sony’s Wii; and OSs in e-book readers, ATMs, cell phones, networking devices, etc.
89 Utility Programs Programs that help to perform maintenance or correct problems with a computer system
90 Table 2.10 Examples of Utility ProgramsPersonal Workgroup Enterprise Software to compress data so that it takes less hard disk space Software that maintains an archive of changes made to a shared document Software to archive contents of a database by copying data from disk to tape Software that assists in determining which files to delete to free up disk space Software that monitors group activity to determine levels of participation Software that monitors network traffic and server loads Antivirus and antispyware software for PCs Software that reports unsuccessful user logon attempts Software that reports the status of a particular computer job TABLE 2.10 Examples of utility programs
91 Middleware Software that allows different systems to communicate and exchange data Can also serve as an interface between the Internet and private corporate systems Service-oriented architecture (SOA): a software design approach using modules to provide specific functions as services to other applications
92 Application Software Application programs’ primary functionTo apply the power of the computer to enable people, workgroups, and the entire enterprise to solve problems and perform specific tasks Many software options are available Software can be selected that best meets the needs of the individual, workgroup, or enterprise
93 Types and Functions of Application SoftwareProprietary software: a one-of-a-kind program for a specific application Owned by the company, organization, or person that uses it Off-the-shelf software: software mass-produced by software vendors Addresses needs that are common across businesses, organizations, or individuals
94 Table 2.11 Proprietary Software Advantages and DisadvantagesYou can get exactly what you need in terms of features, reports, and so on. It can take a long time and significant resources to develop required features. Being involved in the development offers control over the results. In-house system development staff may be hard pressed to provide the required level of ongoing support and maintenance because of pressure to move on to other new projects. You can modify features that you might need to counteract an initiative by competitors or to meet new supplier or customer demands. The features and performance of software that has yet to be developed presents more potential risk. TABLE 2.11 Comparison of proprietary and off-the-shelf software
95 Table 2.11 Off-the-Shelf Software Advantages and DisadvantagesThe initial cost is lower because the software firm can spread the development costs over many customers. An organization might have to pay for features that are not required and never used. The software is likely to meet the basic business needs—you can analyze existing features and the performance of the pack- age before purchasing. The software might lack important features, thus requiring future modification or customization. This lack can be very expensive because users must adopt future releases of the soft- ware as well. The package is likely to be of high quality because many customer firms have tested the software and helped identify its bugs. The software might not match current work processes and data standards. TABLE 2.11 Comparison of proprietary and off-the-shelf software (cont’d.)
96 Application Software: Cloud Computing and Software as a Service (SaaS)Cloud computing provides computing resources on the Internet (the cloud) Examples of public cloud service providers: Amazon Elastic Compute Cloud (EC2), IBM’s Blue Cloud,Sun Cloud, Google AppEngine, and Windows Azure Services Platform Software as a service (SaaS) Businesses subscribe to Web-delivered business application software
97 Personal Application SoftwareAlso called user software or personal productivity software Types of application software: Word processing and spreadsheet analysis Database applications Graphics programs Personal information managers (PIMs) Software suites and integrated packages
98 Workgroup Application SoftwareSupports teamwork with people in the same location or dispersed around the world Groupware helps groups of people work together more effectively Also called collaborative software
99 Enterprise Application SoftwareSoftware that benefits an entire organization Software supporting supply chain management is used by many companies Cost, installation and ability to integrate with other software are major considerations in selecting this software Usability on smartphones and mobile devices is also an important factor
100 Software for Information, Decision Support, and Competitive AdvantageAvailable in every industry Examples: Blackboard and other learning management software Software to visualize and analyze the human genome Software to help pick the next hit song Natural resource planning
101 Programming LanguagesSets of keywords, commands, symbols, and a system of rules for constructing statements: Allows humans to communicate instructions to a computer Visual and object-oriented languages are commonly used
102 Table 2.14 Evolution of Programming LanguagesGeneration Language Approximate Development Date Sample Statement or Action First Machine language 1940s Second Assembly language 1950s MVC Third High-level language 1960s READ SALES Fourth Query and database languages 1970s PRINT EMPLOYEE NUMBER IF GROSS PAY > 1000 TABLE 2.14 Evolution of programming languages
103 Software Issues and TrendsSoftware bug: a defect in a program that keeps it from performing as it should Tips for reducing the impact of software bugs Register all software Check read-me files for work-arounds Access the support area of the manufacturer’s Web site for patches Install the latest software updates
104 Copyrights and LicensesMost software products are protected by law using copyright or licensing provisions: In some cases, you are given unlimited use of software on one or two computers In other cases, you pay for your usage; if you use the software more, you pay more Some software now requires that you register or activate it before it can be fully used
105 Software Upgrades Software companies revise their programs and sell new versions periodically Software upgrades vary widely in the benefits that they provide Developing an upgrading strategy is important for many businesses Helps to ensure that updated software is more stable with fewer errors and problems
106 Global Software SupportSupporting local operations is one of the biggest challenges IS teams face when putting together standardized, company-wide systems Outsourcing global support to one or more third-party distributors is gaining acceptance
107 Summary – Principle 1 Hardware refers to the physical components of a computer that perform the input, processing, storage, and output activities of the computer Processing that uses several processing units is called multiprocessing
108 Summary – Principle 1 (cont’d.)Input and output devices allow users to provide data and instructions to the computer for processing and allow subsequent storage and output Multiple-user computer systems include servers, mainframe computers, and supercomputers
109 Summary – Principle 2 Green computing is concerned with the efficient and environmentally responsible design, manufacture, operation, and disposal of IS-related products Organizations are trying a number of strategies to lower the ongoing cost of data center operations
110 Summary – Principle 3 Software consists of programs that control the workings of the computer hardware The two main categories of software are systems software and application software An operating system (OS) is a set of computer programs that controls the computer hardware to support users’ computing needs
111 Summary – Principle 4 Application software can be proprietary or off the shelf and enables people to solve problems and perform specific tasks Application software applies the power of the computer to solve problems and perform specific tasks Purchasing off-the-shelf software has many advantages, e.g., lower cost and lower risk of failure
112 Summary – Principle 5 All software programs are written in coding schemes called programming languages Programming languages have changed since their initial development in the early 1950s Users frequently use fourth generation and higher-level programming languages to develop their own simple programs
113 Summary – Principle 6 Important software issues and trends include:Software bugs Software licensing and copyrighting Software upgrades Global software support