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Principles of Information Systems Eighth Edition. Hardware: Input, Processing, and Output Devices. Learning Objectives. Describe how to select and organize computer hardware components to support information system (IS) objectives and business needs
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Principles of Information SystemsEighth Edition Hardware: Input, Processing, and Output Devices
Learning Objectives • 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, Eighth Edition
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, Eighth Edition
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, Eighth Edition
Hardware Devices Analogy: A Paper-Based Office Register Storage Output Primary Storage Secondary Storage Input Principles of Information Systems, Eighth Edition
Hardware Components Figure 3.1: Hardware Components Principles of Information Systems, Eighth Edition
Hardware Components in Action • Execution of machine-level instruction • Phase 1 : Instruction Phase – Fetch and Decode • Phase 2 : Execution Phase – Execute and Store • I-time: the time taken to perform phase 1 • E-time: the time taken to perform phase 2 Principles of Information Systems, Eighth Edition
Hardware Components in Action Figure 3.2: Execution of an Instruction Principles of Information Systems, Eighth Edition
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, Eighth Edition
Processing Characteristics and Functions • Computer execute an instruction during a machine cycle • Completing the instruction and execution phase – make up one machine cycle • 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, Eighth Edition
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, Eighth Edition
Physical Characteristics of the CPU • Collection of digital circuits on chips • Electrical current flows through silicon – to turn the digital circuit on or off • Gordon Moore – former Intel’s chairman hypothesised that progress in chip manufacturing: transistor density of chips will double every 18 months (Moore’s Law) Principles of Information Systems, Eighth Edition
Physical Characteristics of the CPU (continued) Figure 3.3: Moore’s Law Principles of Information Systems, Eighth Edition
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 Principles of Information Systems, Eighth Edition
Storage Capacity Table 3.1: Computer Storage Units Principles of Information Systems, Eighth Edition
Types of Memory Figure 3.4: Basic Types of Memory Chips Principles of Information Systems, Eighth Edition
Types of Memory (Cash Memory) Figure 3.5: Cache Memory Principles of Information Systems, Eighth Edition
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 Principles of Information Systems, Eighth Edition
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, Eighth Edition
Parallel Computing (continued) • 2 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, Eighth Edition
Secondary Storage • Permanent storage • Compared with memory, offers the advantages of nonvolatility, greater capacity, and greater economy • Selection of secondary storage : access methods, storage capacities, and portability required - determined by the information system’s objectives • Example: credit card company Principles of Information Systems, Eighth Edition
Access Methods Two types of access methods • Sequential access: records must be retrieved in order in which it’s 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) Principles of Information Systems, Eighth Edition
Devices • Magnetic tapes • Magnetic disks • Optical disks • Digital video disk (DVD) • Holographic Versatile Disc (HVD) • Memory cards • Flash memory • RAID • Virtual tape Principles of Information Systems, Eighth Edition
Magnetic Tapes • Sequential secondary storage medium • Primarily for storing backups • Tapes similar to audio and videocassettes • Portion of tapes are magnetized to represent bits Principles of Information Systems, Eighth Edition
Magnetic Disks • Direct access storage medium • e.g. diskette, hard disks • Allows fast data retrieval Principles of Information Systems, Eighth Edition
Optical Disc • Data is recorded by special lasers that physically burn pits in the disk. • Data accessed – optical disc device (compact disk player) • e.g. CD-ROM – 740MB, CD-RW Principles of Information Systems, Eighth Edition
DVD and HVD • DVD (Digital Video Disc) • Looks like a CD but more storage capacity ~ 135min of digital video. • Software, video games, movies • HVD (Holographic Versatile Disc) • Advanced optical disk – ongoing research • Hold 200GB of data • Write data 10 times faster than DVD Principles of Information Systems, Eighth Edition
Memory cards • Functions as a hard disk drive • Portable, relatively easy to use • Need to use memory card reader/writer Principles of Information Systems, Eighth Edition
Flash Memory • A silicon computer chip • Keeps its memory when the power is shut off • “Flash” – the memory cell is erased or reprogrammed in a single action or flash • e.g. – Migo – keychain device, comes with software that captures files and settings from e-mail, word processing, web browser, presentation programs. Principles of Information Systems, Eighth Edition
RAID and Virtual Tape • Storage technologies • RAID – • Redundant array of independent /inexpensive disks • duplicate existing data on drives, provides exact copy, store on different physical disk drives • Virtual Tape • manages less frequently needed data • Move data to less costly storage media • Software – virtual tape server • Vendor – IBM and Storage Technology Principles of Information Systems, Eighth Edition
Enterprise Storage Options • Needs to store massive amount of data • 3 forms: • Attached storage • tape, hard disks, optical devices • Simple, cost effective - single users and small groups • Not allowed share storage • Network-attached storage (NAS) • Storage devices attach to a network • Users can share and access same information Principles of Information Systems, Eighth Edition
Enterprise Storage Options (continued) • Storage area network (SAN) • Special purpose, high speed network • Provides direct connections between data-storage devices and computer • Integrates different types of storage subsystems Figure 3.9: Storage Area Network (SAN) Principles of Information Systems, Eighth Edition
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, Eighth Edition
Characteristics and Functionality • Nature of data- 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, Eighth Edition
Input Devices • Personal computer input devices • Keyboard • Mouse • Speech-recognition technology • Input devices that recognize human speech • e.g. automate account identification process • Digital cameras • Terminals • Input and display devices that perform data entry and input at same time • Office, warehouse, factory Principles of Information Systems, Eighth Edition
Input Devices (continued) • Scanning devices • Optical data readers • Special scanner • OMR – standardized tests • OCR – convert handwritten to typed doc into digital data • Magnetic stripe card • Swipe card • Point-of-sale (POS) devices • Used in retail operations to enter sales information Principles of Information Systems, Eighth Edition
Magnetic ink character recognition (MICR) devices • A system for reading banking data quickly • Use special ink readable by people and computers • e.g. bank check Principles of Information Systems, Eighth Edition
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, Eighth Edition
Output Devices • Display monitors • Liquid crystal displays (LCDs) • Organic light-emitting diodes (OLEDs) • Printers and plotters • Digital audio player Principles of Information Systems, Eighth Edition
Special-Purpose Input and Output Devices • Computer-based navigation systems • GPSs (Global positioning system), satellite based radio navigating system • Guide to specific destination • Multiple function printers • Print, copy, fax,scan • Eyebud screens • Portable media devices • Display video in front of one eye Principles of Information Systems, Eighth Edition
Computer System Types, Selection, and Upgrading Computer classification: • Special-purpose computers: used for limited applications by military and scientific research groups • General-purpose computers: • used for a wide variety of applications • Single user at a time, multiple concurrent users Principles of Information Systems, Eighth Edition
Computer System Types • Handheld computers – single user, small size, portable • Portable computers – laptops, notebooks, tablet • Thin client • Low-cost, no extra drives, limited capabilities • Desktop computers Principles of Information Systems, Eighth Edition
Computer System Types (continued) • Workstations – more powerful than personal computer, similar size to desktop, heavy mathematical computing, CAD. • Servers – to perform special tasks, e.g. running network or Internet application. Principles of Information Systems, Eighth Edition
Computer System Types (continued) • Mainframe computers – large, powerful computer, shared by hundreds of concurrent users, connected via terminals • Supercomputers • most powerful computers, fastest processing speed, highest performance. • Special purpose machines – weather forecast, military application, simulation of golf club designs. Principles of Information Systems, Eighth Edition
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, Eighth Edition
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, Eighth Edition
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, Eighth Edition
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. Principles of Information Systems, Eighth Edition