Week No. 2 and 3- Topic 3- Hardware.pptx

Chapter 03: Hardware: Input, Processing, Output and Storage Devices Stair, Reynolds and Chesney: Principles of Business Information Systems, Fourth edition (9781473774605) © Cengage Learning 2021 Principles • Assembling an effective, efficient set of computer hardware devices requires understandi...

Chapter 03: Hardware: Input, Processing, Output and Storage Devices Stair, Reynolds and Chesney: Principles of Business Information Systems, Fourth edition (9781473774605) © Cengage Learning 2021 Principles • 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 • 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 For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Hardware for processing • Each computer processes its input through one or more central processing units and primary storage For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Central Processing Unit (CPU( CPU consists of three associated elements: • The Arithmetic/Logic Unit (ALU) performs mathematical calculations and makes logical comparisons. • The Control Unit (CU) sequentially accesses program instructions, decodes them, and coordinates the flow of data in and out of the ALU, registers, primary and secondary storage, and various output devices. • Registers are high-speed storage areas used to temporarily hold small units of program instructions and data immediately before, during, and after execution by the CPU. For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Central Processing Unit (CPU) For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Hardware Components in Action » The instruction phase Step 1: fetch instruction Step 2: decode instruction » The execution phase Step 3: execute instruction Step 4: store results » Instruction time (I-time) » Execution time (E-time) For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Machine Cycle For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Storage: Primary storage • Primary storage or main memory provides the CPU with a working storage area for program instructions and data • The chief feature of main memory is that it rapidly provides the data and instructions to the CPU as it is closely associated with the CPU. • Main memory devices contain thousands of circuits imprinted on a silicon chip. Each circuit is either conducting electrical current (on) or not (off), known as binary digits, or bits. • Data is stored in memory as a combination of on or off circuit states, with each character represented by 8 bits. • It holds the program instructions and data immediately before or after the registers. For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Types of Memory » Random Access Memory (RAM) is temporary and volatile and Loses all data when the power is disconnected. » Types of RAM – Static random access memory (SRAM) used for high-speed registers and caches – Dynamic random access memory (DRAM) used for main memory For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Types of Memory » Cache memory: a type of high-speed memory that a processor can access more rapidly than main memory. For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Cache Memory For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Types of Memory • Read Only Memory (ROM) is nonvolatile – It provides permanent storage for data and instructions that do not change. For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Multiprocessing  Multiprocessing: The simultaneous execution of two or more instructions at the same time  A coprocessor speeds processing Executes specific types of instructions while the CPU works on another processing activity  A multicore microprocessor combines two or more independent processors into a single computer. For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Parallel Computing  Parallel computing: The simultaneous execution of the same task on multiple processors to obtain results faster.  Grid computing: a collection of computers working in a coordinated manner to solve a common problem. For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Secondary storage • The amount of data that companies store digitally is increasing at a rate of close to 100 per cent per year! • Secondary storage, also called permanent storage, allows organizations to store large amounts of data and instructions more permanently than main memory allows. • Compared with main memory, secondary storage offers the advantages of non-volatility, greater capacity, and greater economy For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Access Methods » Sequential access – Data must be retrieved in the order in which it is 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) For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Secondary Storage Devices » Magnetic tapes: – Sequential secondary storage medium. – Primarily for storing backups of critical organizational data. » Magnetic disks: – Direct-access storage device. For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Secondary Storage Devices » Optical secondary storage devices: [ – Compact disc read-only memory (CD-ROM): • Storage capacity is 740 MB – Digital video disc (DVD): • 6 x capacity of CD – Blue-ray high-definition video disk: • 3 x capacity of DVD For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Secondary Storage Devices » Solid State Drive (SSD) – Store data in memory chips rather than magnetic or optical media. – Have few moving parts, so they are less fragile than hard disk drives. – Disadvantages of SSD • High cost per GB of data storage. • Lower capacity compared to current hard drives(HD). For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Enterprise storage options • Attached storage: the devices discussed before, attached to a single computer. • Network-attached storage: storage devices that attach to a network instead of to a single computer • Storage area network: similar to network-attached storage, except there is a dedicated, special-purpose, high-speed network that provides direct connections between data-storage devices and computers across the enterprise For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Enterprise storage options For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Data input • Input often requires transferring human-readable data, such as a sales order, into the computer system. • ‘Human-readable’ means data that people can read and understand. A sheet of paper containing inventory figures is an example of human-readable data. • Machine-readable data, such as a bar code, can be understood and read by computer devices • Getting data into the computer system is a two-stage process: – human-readable data is converted into a machine-readable form through data entry – transferring the machine-readable data into the system. This is data input For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Input devices 1 • Keyboard and mouse • Speech-recognition technology: enables a computer equipped with a source of audio input such as a microphone to interpret human speech as an means of providing data or instructions to the computer • Digital cameras For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Input devices 2 • Scanning devices • Optical data readers: optical mark recognition (OMR) such as that used on a multiple choice exam to detect a mark on a page, and optical character recognition (OCR) to ‘read’ handwritten (or typed) characters • Magnetic ink character recognition (MICR) devices: used to read ‘magnetic ink’, found at the bottom of bank cheques For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Input devices 3 • Point-of-sale devices: for example, a bar code reader • Automated teller machine (ATM) devices: specialpurpose input/output devices that bank customers use to perform withdrawals and other transactions with their bank accounts • Pen Input Devices: data can be input by touching a screen with a pen input device, on a tablet PC for instance • Touch-Sensitive Screens For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Output devices 1 • Display Monitors: the display monitor is a device similar to a TV screen that displays output from the computer. • Liquid Crystal Displays (LCDs): LCD displays are flat displays that use liquid crystals to form characters and graphic images on a backlit screen. • Printers and plotters: paper output remains one of the most popular and useful forms of output • Digital audio player: an mp3 player, or iPod • Computer-based navigation systems: GPS systems are becoming more popular with drivers • 3D printers are specialized output devices • E-book readers For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Types of computer system 1 • Handheld computer: also known as pocket PCs, or PDAs these are extremely mobile, multi-function devices • Smart phone: when a handheld computer can also be used to make phone calls, it is a smart phone (note there is no agreed definition on how smart a phone has to be, before it is classed as a smart phone) • Portable Computers: laptops and tablet PCs • Thin Client: low cost, these have limited capabilities and perform only essential applications, so they remain ‘thin’ in terms of the client applications they include For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning Types of computer system 2 • Desktop PC: the traditional view of what a computer looks like • Workstation: more powerful than a Desktop PC, but essentially look the same • Server: used by many users to perform a specific task, typically these have large memory and storage capacities, along with fast and efficient communications abilities. • Mainframe Computers: a large, powerful computer shared by dozens or even hundreds of concurrent users connected to the machine over a network • Supercomputers: the most powerful computers with the fastest processing speed and highest performance, these are specialpurpose machines designed for applications that require extensive and rapid computational capabilities For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning 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 • Secondary storage devices: e.g. magnetic tapes and disks, DVDs, memory cards, etc. • Enterprise storage options: attached storage, networkattached storage (NAS), and storage area network (SAN) For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning 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 special-purpose or general-purpose • Computer system types: handheld computers, portable computers, desktop computers, workstations, servers, etc. For use with Principles of Business Information Systems, 4e by Stair, Reynolds & Chesney © 2021 Cengage Learning