Principles of Information Systems Eighth Edition Hardware: Input, Processing, and Output Devices Principles of Information Systems Eighth Edition

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

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

Table 3.1: Computer Storage Units Storage Capacity Table 3.1: Computer Storage Units Principles of Information Systems, Eighth Edition

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 – Virtual Tape 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