Principles of Information Systems Principles of Information Systems

Principles of Information Systems

Principles of Information Systems Chapter 3 Hardware: Input, Processing, and Output Devices Principles of Information Systems

Why Learn About 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 Principles of Information Systems 3

Introduction • Hardware: any machinery (most of which use digital circuits) that assists in the input, processing, storage, and output activities of an information system • When making hardware decisions, businesses must consider how the hardware can support: – Objectives of the information system – Goals of the organization Principles of Information Systems 4

Computer Systems: Integrating The Power of Technology • Choosing the right computer hardware requires understanding its relationship to the information system and needs of the organization • Hardware objectives are subordinate to, but supportive of, the information system and the current and future needs of the organization Principles of Information Systems 5

Hardware Components • • • Central processing unit (CPU) Input devices Output devices Communications devices Primary storage devices Secondary storage devices Principles of Information Systems 6

Hardware Components (continued) Figure 3. 1: Hardware Components Principles of Information Systems 7

Hardware Components • Hardware Components – Central processing unit (CPU) • Arithmetic/logic unit, the control unit, and the register areas – Arithmetic/logic unit (ALU) • Performs mathematical calculations and makes logical comparisons Principles of Information Systems 8

Hardware Components (continued) – Control unit • Sequentially accesses program instructions, decodes them, and coordinates the flow of data in and out of the ALU, registers, primary storage, and even secondary storage and various output devices – Registers • High-speed storage areas – Primary storage • Closely associated with the CPU Principles of Information Systems, Ninth Edition 9

Hardware Components in Action (continued) Figure 3. 2: Execution of an Instruction Principles of Information Systems 10

Hardware Components in Action • • Step 1: Fetch instruction Step 2: Decode instruction Step 3: Execute instruction Step 4: Store results Principles of Information Systems 11

Hardware Components in Action (continued) Principles of Information Systems 12

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 Principles of Information Systems 13

Processing Characteristics and Functions • Machine cycle time is measured in: – Nanoseconds (1 billionth of a second) – Picoseconds (1 trillionth of a second) – MIPS (millions of instructions per second) Principles of Information Systems 14

Processing Characteristics and Functions (continued) • Clock speed: series of electronic pulses produced at a predetermined rate that affects machine cycle time – Often measured in: • Megahertz (MHz): millions of cycles per second • Gigahertz (GHz): billions of cycles per second • Microcode: predefined, elementary circuits and logical operations that the processor performs when it executes an instruction Principles of Information Systems 15

Physical Characteristics of the CPU • Digital circuits on chips • Electrical current flows through silicon • Moore’s Law: transistor density of chips will double every 18 months Principles of Information Systems 16

Physical Characteristics of the CPU (continued) Figure 3. 3: Moore’s Law Principles of Information Systems 17

Memory Characteristics and Functions • Main memory – Located physically close to the CPU, but not on the CPU chip itself – Rapidly provides data and instructions to the CPU • Storage Capacity – Eight bits together form a byte (B) Principles of Information Systems 18

Storage Capacity Table 3. 1: Computer Storage Units Principles of Information Systems 19

Types of Memory • Random access memory (RAM) – Temporary and volatile • Types of RAM – EDO (Extended Data Out) – DRAM (Dynamic RAM) – SDRAM (Synchronous DRAM) Principles of Information Systems 20

Types of Memory (continued) • Types of nonvolatile memory – ROM (read-only memory) – PROM (programmable read-only memory) – EPROM (erasable programmable read-only memory) • Cache memory: high-speed memory that a processor can access more rapidly than main memory Principles of Information Systems 21

Types of Memory (continued) Figure 3. 4: Basic Types of Memory Chips Principles of Information Systems 22

Types of Memory (continued) Figure 3. 5: Cache Memory Principles of Information Systems 23

Multiprocessing • Multiprocessing: simultaneous execution of two or more instructions at the same time • Multiprocessing using coprocessors – Coprocessor: speeds processing by executing specific types of instructions while the CPU works on another processing activity • Multicore microprocessor – Combines two or more independent processors into a single computer Principles of Information Systems 24

Parallel Computing • Parallel computing: simultaneous execution of the same task on multiple processors to obtain results faster • Massively parallel processing: – Speeds processing by linking hundreds or thousands of processors to operate at the same time, or in parallel – Each processor has its own bus, memory, disks, copy of the operating system, and applications Principles of Information Systems 25

Parallel Computing (continued) • Different approaches to achieving parallel computing – Single instruction/multiple data (SIMD) parallel processors – Multiple instruction/multiple data (MIMD) parallel processors • Grid computing: use of a collection of computers, often owned by multiple individuals or organizations, to work in a coordinated manner to solve a common problem Principles of Information Systems 26

Parallel Computing (continued) • Cloud computing – Uses giant cluster of computers, that serves as a host, to run applications that require highperformance computing – Supports a wider variety of applications than grid computing – Pools computing resources so they can be managed primarily by software rather than people Principles of Information Systems, Ninth Edition 27

Secondary Storage • Compared with memory, offers the advantages of nonvolatility, greater capacity, and greater economy • Access methods, storage capacities, and portability required are determined by the information system’s objectives Principles of Information Systems 28

Access Methods • Sequential access: records must be retrieved in order – 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) Principles of Information Systems 29

Devices • Magnetic tapes • Magnetic disks • RAID )Redundant Array of Inexpensive Disk( • Virtual tape • Optical disks • Digital video disk (DVD( • Holographic versatile disc (HVD( Principles of Information Systems 30

Devices (continued) • Memory cards • Flash memory Principles of Information Systems 31

Enterprise Storage Options • Attached storage • Network-attached storage (NAS) • Storage area network (SAN) Principles of Information Systems 32

Enterprise Storage Options (continued) Figure 3. 9: Storage Area Network Principles of Information Systems 33

Input and Output Devices: The Gateway to Computer Systems • Through input and output devices, people provide data and instructions to the computer and receive results from it • Selection of input and output devices depends on organizational goals and IS objectives Principles of Information Systems 34

Characteristics and Functionality • Data can be human-readable or machine-readable • Data entry: converts human-readable data into machine-readable form • Data input: transfers machine-readable data into system • Source data automation: capturing and editing data where the data is initially created and in a form that can be directly input to a computer Principles of Information Systems 35

Input Devices • Personal computer input devices – Keyboard – Mouse • Speech-recognition technology • Digital cameras • Terminals Principles of Information Systems 36

Input Devices (continued) • • • Scanning devices Optical data readers Magnetic ink character recognition (MICR) devices Magnetic stripe card Point-of-sale (POS) devices Principles of Information Systems 37

Input Devices (continued) • • • Automated teller machine (ATM) devices Pen input devices Touch-sensitive screens Bar-code scanners Radio Frequency Identification (RFID) Principles of Information Systems 38

Input Devices (continued) Principles of Information Systems 39

Output Devices • • • Display monitors Plasma displays Liquid crystal displays (LCDs) Organic light-emitting diodes (OLEDs) Printers and plotters Digital audio player Principles of Information Systems 40

Special-Purpose Input and Output Devices • Multiple function printers • E-books - Computer-based navigation systems – Digital media equivalent of a conventional printed book • Eyebud screens – Portable media devices that display video in front of one eye Principles of Information Systems 41

Computer System Types, Selection, and Upgrading • Special-purpose computers: used for limited applications by military and scientific research groups • General-purpose computers: used for a wide variety of applications Principles of Information Systems 42

Computer System Types • Handheld computers Principles of Information Systems บทท 2 คอมพวเตอรฮารดแวรและอปกรณอน ๆ 43

Computer System Types • Portable computers • Thin client Principles of Information Systems 44

Computer System Types • Desktop computers Principles of Information Systems 45

Computer System Types (continued) • Workstations • Servers Principles of Information Systems 46

Computer System Types (continued) • Servers Principles of Information Systems 47

Computer System Types (continued) • Mainframe computers Principles of Information Systems 48

Computer System Types (continued) • Supercomputers Principles of Information Systems 49

Selecting and Upgrading Computer Systems • Dispose of old equipment properly • Consider factors such as speed, cost, and performance when upgrading – – Hard drive Main memory Printer DVD burners Principles of Information Systems 50

Summary • Hardware: machinery that assists in the input, processing, storage, and output activities of an information system • Hardware components: central processing unit (CPU), input and output devices, communications devices, primary storage devices, and secondary storage devices • Random access memory (RAM): temporary and volatile • ROM (read-only memory): nonvolatile Principles of Information Systems 51

Summary (continued) • Multiprocessing: simultaneous execution of two or more instructions at the same time • Sequential access: records must be retrieved in order • Direct access: records can be retrieved in any order • Examples of secondary storage devices: magnetic tapes and disks, DVDs, memory cards, etc. • Enterprise storage options: attached storage, network-attached storage (NAS), and storage area network (SAN) Principles of Information Systems 52

Summary (continued) • Examples of input devices: keyboards, mice, voicerecognition devices, terminals, scanning devices, and touch-sensitive screens • Examples of output devices: display monitors, liquid crystal displays (LCDs), printers, and plotters • Computers can be classified as either specialpurpose or general-purpose • Computer system types: handheld computers, portable computers, desktop computers, workstations, servers, etc. Principles of Information Systems 53

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Principles and Learning Objectives • Assembling an effective, efficient set of computer hardware devices requires understanding their role in supporting the underlying information systems and the needs of the organization; the computer hardware objectives are subordinate to, but supportive of, the information systems and the needs of the organization Principles of Information Systems 55

Principles and Learning Objectives (continued) • When selecting computer hardware, you must consider the current and future needs of the information systems and the organization; your choice of a hardware device should always allow for later improvements to meet evolving organizational needs Principles of Information Systems 56

Principles and Learning Objectives (continued) – Describe how to select and organize computer hardware components to support information system (IS) objectives and business needs – Describe the power, speed, and capacity of central processing and memory devices – Describe the access methods, capacity, and portability of secondary storage devices – Discuss the speed, functionality, and importance of input and output devices – Identify popular classes of computer systems and discuss the role of each Principles of Information Systems 57

Review question #3 Principles of Information Systems 58

สว สด Principles of Information Systems 59