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

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 Describe how to select and organize computer hardware components to support information system (IS) objectives and business needs Principles of Information Systems, Eighth Edition

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 Describe the power, speed, and capacity of central processing and memory devices Describe the access methods, capacity, and portability of secondary storage devices Principles of Information Systems, Eighth Edition

Principles and Learning Objectives (continued) 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

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, Eighth Edition

Hardware Components Central processing unit (CPU) Input devices Output devices Principles of Information Systems, Eighth Edition

Hardware Components (continued) Communications devices Primary storage devices Secondary storage devices Principles of Information Systems, Eighth Edition

Hardware Components (continued) Figure 3.1: Hardware Components Principles of Information Systems, Eighth Edition

Hardware Components in Action Step 1: Fetch instruction from memory Step 2: Decode instruction Step 3: Execute instruction Step 4: Store results Step Description 1.Fetch Instruction from Memory 2.Decode Instruction 3.Perform ALU Operations 4.Memory Access (for load/store) 5.Store ALU result to register file 6.Update PC Principles of Information Systems, Eighth Edition

Hardware Components in Action (continued) 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 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 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, 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

Types of Memory Random access memory (RAM) Types of RAM Temporary and volatile Types of RAM EDO (Extended Data Out) DRAM (Dynamic RAM) SDRAM (Synchronous DRAM) Principles of Information Systems, Eighth Edition

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, Eighth Edition

Types of Memory (continued) Figure 3.4: Basic Types of Memory Chips Principles of Information Systems, Eighth Edition

Types of Memory (continued) 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) 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 Compared with memory, offers the advantages of non volatility, greater capacity, and greater economy Access methods, storage capacities, and portability required are determined by the information system’s objectives Principles of Information Systems, Eighth Edition

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, Eighth Edition

Devices Magnetic tapes Magnetic disks RAID Virtual tape Optical disks Principles of Information Systems, Eighth Edition

Devices (continued) Digital video disk (DVD) Holographic Versatile Disc (HVD) Memory cards Flash memory Principles of Information Systems, Eighth Edition

Enterprise Storage Options Attached storage Network-attached storage (NAS) Storage area network (SAN) تشارك موارد التخزين كانها على اقراص صلبة اما الاخرى مجرد ارتباطها ب ipتعرض خدمة تخزين عبر الشبكه Principles of Information Systems, Eighth Edition

Enterprise Storage Options (continued) Figure 3.9: Storage Area Network 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 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 Digital cameras Terminals Principles of Information Systems, Eighth Edition

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, 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  الصمامات الثنائية العضوية الباعثة للضوء OLED في شاشات التلفزيون وشاشات الكمبيوتر، والصغيرة، وشاشات نظام المحمولة مثل الهواتف النقالة وأجهزة المساعد الرقمي الشخصي، والساعات، والإعلانات، والمعلومات، وإشارة. كما تستخدم وعلى مجال واسع للإنارة العامة. Principles of Information Systems, Eighth Edition

Special-Purpose Input and Output Devices Computer-based navigation systems Multiple function printers Eyebud screens Principles of Information Systems, Eighth Edition

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, Eighth Edition

Computer System Types Handheld computers Portable computers Thin client Desktop computers Principles of Information Systems, Eighth Edition

Computer System Types (continued) Workstations Servers Mainframe computers Supercomputers 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