Management Information Systems, Sixth Edition Chapter 4: Business Hardware

Objectives List major hardware components of computers and explain their functions Classify computers into major categories, and identify their strengths and weaknesses Identify and evaluate key criteria for deciding what computers or related devices to purchase Discuss the possible health hazards of computer use Management Information Systems, Sixth Edition

Computer Hardware Components Hardware: physical components of computers and related electronic devices Consider software before hardware Computer must handle four operations: Accept data Store data and instructions Process data Output data and/or information Management Information Systems, Sixth Edition

Computer Hardware Components (continued) In general, every computer has the following components: Input devices Central processing unit (CPU) Internal memory Storage Output devices Input devices: receive signals from outside of computer and transfer them into the computer Management Information Systems, Sixth Edition

Computer Hardware Components (continued) Management Information Systems, Sixth Edition

Computer Hardware Components (continued) Central processing unit (CPU) Accepts instructions and data Decodes and executes instructions Stores results (output) in memory Internal (or primary) memory: stores data and instructions before and after CPU processes them RAM: random access memory ROM: read-only memory Management Information Systems, Sixth Edition

Computer Hardware Components (continued) Motherboard: circuit board containing the CPU and primary memory Storage: magnetic disks, magnetic tapes, optical discs, DVDs, and flash memory Allows permanent storage Output devices: deliver information from the computer to the user Monitors and printers are the most common output devices Audio devices also deliver output Management Information Systems, Sixth Edition

Computer Hardware Components (continued) Bit: Binary digit 0 or 1 Byte: a standard group of eight bits Most characters can be represented by a single byte Computer memory and storage capacity are measured in megabytes (MB), gigabytes (GB), and terabytes (TB) Management Information Systems, Sixth Edition

Computer Hardware Components (continued) Management Information Systems, Sixth Edition

Classification of Computers Computers vary in size and power Classified by power Power is determined mainly by processing speed and memory size More powerful computers are more expensive Management Information Systems, Sixth Edition

Supercomputers Supercomputers: most powerful computers at any given time Largest in physical size and most expensive Designed for complex arithmetic calculations Generally impractical for business purposes Parallel processing: multiple processors running simultaneously Also known as multiprocessing Management Information Systems, Sixth Edition

Mainframe Computers Mainframe computers: store large amounts of data and business transactions Less expensive and less powerful than supercomputers Often used by banks, universities, and insurance companies as a central computer 40-50% of world’s business data resides on mainframes Use multiple processors Management Information Systems, Sixth Edition

Midrange Computers Midrange computers: often act as servers within organizations or through the Internet Smaller and less powerful than mainframes Serve hundreds of users that connect from personal computers Use multiple processors Management Information Systems, Sixth Edition

Microcomputers Microcomputers: personal computers, notebook computers, and handhelds Workstation: more powerful microcomputer used for CAD, CAM, and scientific applications Power of microcomputers doubles about every two years Management Information Systems, Sixth Edition

Computers on the Go: Notebook, Handheld, and Tablet Computers Notebook (or laptop) computer: compact personal computer powered by rechargeable battery New models include wireless technology Personal digital assistant (PDA): handheld computer Stylus: pen-like device used to enter data through a touch screen Tablet computer: PC in the form of a thick writing tablet that recognizes handwriting Management Information Systems, Sixth Edition

Converging Technologies Technology convergence: building several technologies into a single piece of hardware Prominent in handheld units Commonly merged technologies include: Cell phones Television Digital cameras Digital sound recorder MP3 players Management Information Systems, Sixth Edition

A Peek Inside the Computer Professionals must know about computer components to understand their power and capabilities They use this knowledge to make good decisions in purchasing or recommending a computer Management Information Systems, Sixth Edition

The Central Processing Unit CPU has two units to store and process data Control unit and arithmetic logic unit CPU is a silicon chip with multiple circuits Also known as microprocessor Multicore processors: processors that combine two or more CPUs or “cores” on a single chip Multithreading: processing more than one program, or several parts of a program, at the same time Management Information Systems, Sixth Edition

The Central Processing Unit (continued) Management Information Systems, Sixth Edition

The Central Processing Unit (continued) Microprocessors are embedded with transistors Transistor: a semiconductor that can represent binary code’s two states CPU machine cycle: Time period during which the CPU fetches, decodes, and executes each instruction CPU clock: special circuitry on the processor that synchronizes all tasks Clock rate: number of pulses per second A machine cycle takes several clock pulses Management Information Systems, Sixth Edition

The Central Processing Unit (continued) Management Information Systems, Sixth Edition

The Central Processing Unit (continued) Data word: maximum number of bits that the control unit can fetch from primary memory in a single machine cycle Current microcomputers have words of 32 or 64 bits Arithmetic logic unit: the part of the CPU that performs arithmetic and logical operations Management Information Systems, Sixth Edition

Computer Power Computer power depends on processing speed and memory capacity Bus: electronic lines or traces used for communication inside computer Throughput: number of bits per second that the bus can accommodate MIPS: millions of instructions per second, a common measure of computer speed Management Information Systems, Sixth Edition

Input Devices Computers must receive input to produce output Input devices include machines and devices used to enter instructions and data into computer Common input devices include: Keyboard Trackball Microphone Scanner Management Information Systems, Sixth Edition

Keyboard Keyboard: an input device that contains keys that users press to enter data Includes letters, numbers, punctuation, and function keys QWERTY: standard keyboard layout Dvorak: keyboard layout that allows faster typing Ergonomics: the study of the comfort and safety of humans in the workplace Ergonomic keyboard: fits the natural position of forearms and prevents injury Management Information Systems, Sixth Edition

Mouse, Trackball, and Trackpad Mouse: input device that controls an on-screen pointer to facilitate point-and-click approach Has one to five buttons for clicking, locking, dragging Trackball: similar to mouse, but user manipulates a ball within the device to indicate movement on the screen Trackpad: cursor movement is controlled by moving a finger over a touch-sensitive pad Mice and similar devices can be wireless units Management Information Systems, Sixth Edition

Touch Screen Touch screen: both an input and an output device Often used for public applications, such as kiosks Prevalent in handheld devices, GPS devices, and mobile phones Allows the user to navigate and select by touching the screen Management Information Systems, Sixth Edition

Source Data Input Devices Source data input devices: copy data directly from sources such as bar codes, credit cards, and checks Optical mark recognition devices detect positions of marks or characters Optical character recognition (OCR) devices try to interpret handwritten and printed text Magnetic-ink character recognition (MICR): detects magnetic ink on checks Management Information Systems, Sixth Edition

Source Data Input Devices (continued) Magnetic strips on credit cards store encoded data Bar codes on products and packages store encoded information Management Information Systems, Sixth Edition

Source Data Input Devices (continued) Management Information Systems, Sixth Edition

Imaging Imaging: converts documents into images Saves paper More efficient retrieval and filing Scanned document images can be: Indexed and linked to relevant records in databases Easily retrieved Original paper documents can be destroyed after scanning Management Information Systems, Sixth Edition

Speech Recognition Speech (or voice) recognition: process of translating human speech into computer-readable data and instructions Receives input from microphone and processes it with software Speech-operated computers may increase noise level in offices and add distraction Management Information Systems, Sixth Edition

Output Devices Output device: a device that delivers results of computer processing Popular output devices include: Monitors Printers Speakers In the future, smell output is possible Management Information Systems, Sixth Edition

Monitors Pixel (picture element): small dots that make up the images on a monitor Cathode-ray tube: inner side of screen has layer of phosphoric dots that make up the pixels Electron gun receives instructions from computer and sweeps the pixels Flat-panel monitor: advantages include lower power use, sharper images, and slim profile Liquid crystal display (LCD) monitor: uses a liquid crystal filled screen Management Information Systems, Sixth Edition

Monitors (continued) Monitor price depends on: Size, measured as the diagonal length of the screen Brightness Contrast ratio (the higher the better) Pixel pitch (closeness of the pixels) Resolution: a measure of picture sharpness Number of pixels in the width and height of the screen Management Information Systems, Sixth Edition

Printers Nonimpact printer: does not mechanically impact the paper Laser printer is most common in business Others include ink-jet and electrothermal printers Speed is measured in pages per minute (ppm) Density measured in dots per inch (DPI) Impact printers: reproduce image by using mechanical impact Dot-matrix printer: tiny pins strike ink ribbon against paper Management Information Systems, Sixth Edition

Storage Media Data must be stored on nonvolatile medium Data is retained even when the storage device is not connected to electrical power Storage devices differ in the technology used to maintain data and physical structure Evaluate storage devices by comparing: Cost Capacity Access speed Access mode Management Information Systems, Sixth Edition

Modes of Access Sequential storage: data is organized one record after another Must read through all records that are stored prior to the desired record Direct access: records are organized by physical address on the device A record can be accessed directly (randomly) Flash drives: small storage devices that connect via universal serial bus (USB) Direct access storage media is the only practical way to organize and query databases Management Information Systems, Sixth Edition

Modes of Access (continued) Management Information Systems, Sixth Edition

Magnetic Tapes Magnetic tapes: similar to tapes used in tape recorders and VCRs, usually as cartridges Provide lowest cost (bytes per dollar) Can back up all data Takes a long time to copy from tape Tapes are unreliable after long periods of time or usage Management Information Systems, Sixth Edition

Magnetic Disks Magnetic disk: most widely used storage medium Includes hard disks and floppy disks Hard disk: stack of several rigid platters installed in the same box that holds the CPU Stores up to one TB of data External hard disks connect to computer through USB port Management Information Systems, Sixth Edition

Optical Discs Optical disc: recorded by treating the disc surface to reflect light in different ways Two basic categories of optical disk: Compact discs (CDs) Digital video discs (DVDs) Compact discs: available as read-only, recordable, and rewritable DVDs: store 4.7 GB per side Optical discs are slower than hard disks Management Information Systems, Sixth Edition

Optical Tape Optical tape: uses same technology as optical discs to store and retrieve data Bits are organized sequentially, similar to magnetic tape Mainly used in digital video camcorders Management Information Systems, Sixth Edition

Flash Memory Flash memory: rewritable memory chip that holds content without power Consumes very little power Does not need a constant power supply Fast access times Relatively immune to shock or vibration Available as memory card and USB drive Solid state disk: storage media that does not have latency time Management Information Systems, Sixth Edition

DAS, NAS, and SAN Direct access storage (DAS): disk or array of disks or tapes directly connected to server Easy to deploy and manage Does not relieve any of server’s workload Network-attached storage (NAS): device designed for networked storage Includes both the storage media and the software to manage it Offloads processing from the server Highly scalable Management Information Systems, Sixth Edition

DAS, NAS, and SAN (continued) Storage area network (SAN): a network fully devoted to storage and transfer of data Managed separately from the rest of the LAN May combine DAS and NAS devices Can transfer larger blocks of data at higher speeds Expensive and complex to manage RAID: redundant array of independent disks Used by DAS, NAS, and SAN Fault-tolerant: can continue even through disk failures due to redundancy Management Information Systems, Sixth Edition

Business Considerations in Evaluating Storage Media When purchasing storage devices, managers must consider: Purpose of data storage Amount of data to be stored Required speed of data storage and retrieval Unit space and portability of the device Cost Reliability and life expectancy Trade-offs Management Information Systems, Sixth Edition

Business Considerations in Evaluating Storage Media (continued) Management Information Systems, Sixth Edition

Considerations in Purchasing Hardware Companies must consider the following when selecting equipment to purchase: Power of the equipment (memory size, capacity, speed) Expansion slots and ports (sockets used to connect computer to external devices) Monitor type and resolution Ergonomics Compatibility with existing hardware, software, and networks Management Information Systems, Sixth Edition

Considerations in Purchasing Hardware (continued) Considerations (continued): Hardware footprint (physical size of equipment) Reliability of vendor Warranty policy and post-warranty support Power consumption and noise Cost Backward compatibility: the capability to work with older hardware or software Management Information Systems, Sixth Edition

Management Information Systems, Sixth Edition

Scalability and Updating Hardware Scalability: resources can be expanded or upgraded to provide increased power Not all hardware is scalable Leasing hardware is a valid option to avoid short useful lifetime of hardware Management Information Systems, Sixth Edition

Summary Understanding hardware is important for purchasing decisions Computers are classified according to power All computers have a CPU to process instructions Clock rate measures the speed of a CPU Data word: the number of bits the computer can process in a single cycle Management Information Systems, Sixth Edition

Summary (continued) Computer power: measured by its speed, memory size, and number of processor cores RAM: volatile memory that forms the largest part of computer’s memory ROM is nonvolatile; it does not require power Imaging devices help process text and graphics When evaluating external storage, consider transfer rate, capacity, portability, and form of data organization supported Management Information Systems, Sixth Edition

Summary (continued) Data is organized sequentially on tapes Direct access storage devices such as RAM, magnetic disks, and optical discs allow random access Databases require direct access storage devices When purchasing hardware, professionals should consider cost, power, scalability, and compatibility Information technology may pose health risks such as carpal tunnel syndrome Management Information Systems, Sixth Edition