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

Principles of Information Systems3 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 Systems4 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 Systems5 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 Systems6 Hardware Components Central processing unit (CPU) Input devices Output devices Communications devices Primary storage devices Secondary storage devices

Principles of Information Systems7 Hardware Components (continued) Figure 3.1: Hardware Components

Principles of Information Systems8 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 8 Hardware Components

Principles of Information Systems9 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 Edition9

Principles of Information Systems10 Hardware Components in Action (continued) Figure 3.2: Execution of an Instruction

Principles of Information Systems11 Hardware Components in Action Step 1: Fetch instruction Step 2: Decode instruction Step 3: Execute instruction Step 4: Store results

Principles of Information Systems12 Hardware Components in Action (continued)

Principles of Information Systems13 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 Systems14 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 Systems15 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 Systems16 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 Systems17 Physical Characteristics of the CPU (continued) Figure 3.3: Moore’s Law

Principles of Information Systems18 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 Systems19 Storage Capacity Table 3.1: Computer Storage Units

Principles of Information Systems20 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 Systems21 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 Systems22 Types of Memory (continued) Figure 3.4: Basic Types of Memory Chips

Principles of Information Systems23 Types of Memory (continued) Figure 3.5: Cache Memory

Principles of Information Systems24 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 Systems25 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 Systems26 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 Systems27 Parallel Computing (continued) Cloud computing –Uses giant cluster of computers, that serves as a host, to run applications that require high- performance 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 Edition27

Principles of Information Systems28 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 Systems29 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 Systems30 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 Systems31 Devices (continued) Memory cards Flash memory

Principles of Information Systems32 Enterprise Storage Options Attached storage Network-attached storage (NAS) Storage area network (SAN)

Principles of Information Systems33 Enterprise Storage Options (continued) Figure 3.9: Storage Area Network

Principles of Information Systems34 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 Systems35 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 Systems36 Input Devices Personal computer input devices –Keyboard –Mouse Speech-recognition technology Digital cameras Terminals

Principles of Information Systems37 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 Systems38 Input Devices (continued) Automated teller machine (ATM) devices Pen input devices Touch-sensitive screens Bar-code scanners Radio Frequency Identification (RFID)

Principles of Information Systems39 Input Devices (continued)

Principles of Information Systems40 Output Devices Display monitors Plasma displays Liquid crystal displays (LCDs) Organic light-emitting diodes (OLEDs) Printers and plotters Digital audio player

Principles of Information Systems41 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 Systems42 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 Systems43 บทที่ 2 คอมพิวเตอร์ฮาร์ดแวร์และอุปกรณ์อื่น ๆ Computer System Types Handheld computers

Principles of Information Systems44 Computer System Types Portable computers Thin client

Principles of Information Systems45 Computer System Types Desktop computers

Principles of Information Systems46 Computer System Types (continued) Workstations Servers

Principles of Information Systems47 Computer System Types (continued) Servers

Principles of Information Systems48 Computer System Types (continued) Mainframe computers

Principles of Information Systems49 Computer System Types (continued) Supercomputers

Principles of Information Systems50 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 Systems51 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 Systems52 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 Systems53 Summary (continued) Examples of input devices: keyboards, mice, voice- recognition 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 special- purpose or general-purpose Computer system types: handheld computers, portable computers, desktop computers, workstations, servers, etc.

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Principles of Information Systems55 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 Systems56 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 Systems57 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 Systems58 Review question #3

Principles of Information Systems59 ส วั ส ดี