Computer Hardware 13 Orasa T.

Identify the major types and uses of microcomputer, midrange, and mainframe computer systems. Outline the major technologies and uses of computer peripherals for input, output, and storage. 13 Learning Objectives

Identify the components and functions of a computer system. Identify the computer system and peripherals you would acquire or recommend for a business of your choice. 13 Learning Objectives (continued)

Computer Systems: End User and Enterprise Computing 13 Section I

All computers are systems of input, processing, output, storage, and control components. Three basic categories –Mainframe –Midrange computers –Microcomputers 13 Types of Computer Systems

Mainframe –Enterprise systems –Superservers –Transaction processors –Supercomputers 13 Types of Computer Systems (continued)

Midrange –Network servers –Minicomputers –Web servers –Multi-user systems 13 Types of Computer Systems (continued)

Microcomputers –Personal computers –Network computers –Technical workstations –PDAs –Information appliances 13 Types of Computer Systems (continued)

The most important category of computers –Desktop –Laptop Workstation computers Network servers 13 Microcomputer Systems

Selection criteria –Solid performance at a reasonable price –Operating system ready –Connectivity 13 Microcomputer Systems (continued)

Network computers –Designed primarily for use with the Internet and corporate intranets –For specialized or limited computing applications –Lower cost of purchase, upgrades, maintenance, and support 13 Microcomputer Systems (continued)

Network computers (continued) –Other benefits Ease of software distribution and licensing Computing platform standardization Reduced end user requirements Improved manageability 13 Microcomputer Systems (continued)

Information appliances –PDAs –Set-top boxes and video-game consoles –Wireless PDAs –Cellular and PCS phones 13 Microcomputer Systems (continued)

Computer terminals –Dumb terminals –Intelligent terminals –Network terminals –Transaction terminals 13 Microcomputer Systems (continued)

Multi-user systems that can manage networks of PCs and terminals Less costly to buy, operate, and maintain than mainframes Popular as network servers Minicomputers 13 Midrange Computer Systems

Large, fast, powerful Handle high transaction processing volumes or complex computational problems Super servers for large client/server networks and high-volume Internet websites Popular for data mining and warehousing 13 Mainframe Computer Systems

Supercomputers –Extremely powerful systems specifically designed for scientific, engineering, and business applications requiring extremely high speeds for massive numeric computations –Use parallel processing architectures –Process at speeds measured in gigaflops and teraflops 13 Mainframe Computer Systems (continued)

Computers are organized according to the following system functions: –Input Keyboards Touch screens Pens Electronic mice Optical scanners Convert data into electronic form 13 The Computer System Concept

–Processing Central Processing Unit (CPU) –Two subunits »Arithmetic-Logic Unit (ALU) »Control Unit 13 The Computer System Concept (continued)

–Output Video display units Printers Audio response units Convert electronic information into human- intelligible form 13 The Computer System Concept (continued)

–Storage Store data and software instructions May also include cache memory Primary storage unit (hard drive) Secondary storage –Magnetic disks –Optical disk drives 13 The Computer System Concept (continued)

–Control The registers and other circuits of the control unit interpret software instructions and transmit directions to the other components of the computer system 13 The Computer System Concept (continued)

Computer processing speeds –Milliseconds (thousandths of a second) –Microseconds (millionths of a second) –Nanoseconds (billionths of a second) –Picoseconds (trillionths of a second) 13 The Computer System Concept (continued)

–Clock speeds Megahertz (MHz) –Millions of cycles per second Gigahertz (GHz) –Billions of cycles per second 13 The Computer System Concept (continued)

Computer Peripherals: Input, Output, and Storage Technologies 13 Section II

Generic name given to all input, output, and secondary storage devices Depend on direct connections or telecommunications links to the CPU All peripherals are online devices 13 Peripherals

Natural user interface –Enter data and commands directly into a computer Electronic mice and touch pads Optical scanning, handwriting recognition, voice recognition 13 Input Technologies

Used for entering data and text Work with your operating system’s graphical user interface (GUI) –Electronic mouse –Trackball –Pointing stick –Touch pad –Touch screen 13 Pointing Devices

Used in many hand-held computers and PDAs –Digitizer pen –Graphics tablet 13 Pen-Based Computing

Digitize, analyze, and classify your speech and its sound patterns Allow operators to perform data entry without using their hands to key in data or instructions Speaker-independent Voice-messaging computers 13 Speech Recognition Systems

Read text or graphics and convert them into digital input Employ photoelectric devices to scan the characters being read 13 Optical Scanning

Optical character recognition (OCR) –Reads OCR characters & codes Merchandise tags Product labels Sort mail, score tests Hand-held optical scanning wands –Reads bar coding –Universal Product Code (UPC) 13 Optical Scanning (continued)

Magnetic stripe technology –Credit cards Smart cards –Embedded microprocessor chip Debit, credit, and other cards Digital cameras –Still cameras –Digital camcorders 13 Other Input Technologies

Magnetic ink character recognition (MICR) technology –Used by banks to sort and post checks and deposit slips –14 characters of a standardized design –Reader-sorters Video Print Storage 13 Other Input Technologies (continued)

Video monitors –Cathode ray tube (CRT) –Liquid crystal displays (LCDs) 13 Video Output

Inkjet –Spray ink onto the page one line at a time Laser –Use an electrostatic process similar to a copier 13 Printed Output

13 Storage Trade-Offs

Computer storage fundamentals –Information is stored through the presence or absence of electronic or magnetic signals Binary representation –1 = ON –0 = OFF 13 Storage Trade-Offs (continued)

Computer storage fundamentals (continued) –Bit The smallest element of data May have a value of either one or zero –Byte Basic grouping of bits Typically, a byte consists of 8 bits and represents one character of data 13 Storage Trade-Offs (continued)

Computer storage fundamentals (continued) –Storage capacities Kilobytes (KB) –1,000 bytes Megabytes (MB) –1 million bytes 13 Storage Trade-Offs (continued)

Computer storage fundamentals (continued) Gigabytes (GB) –1 billion bytes Terabytes (TB) –1 trillion bytes Petabyte (PB) –1 quadrillion bytes 13 Storage Trade-Offs (continued)

Direct and sequential access –Terms direct access and random access describe the same concept –An element of data or instructions can be directly stored and retrieved by selecting and using any of the locations on the storage media Each storage position –Has a unique address –Can be individually accessed in approximately the same time 13 Storage Trade-Offs (continued)

Direct and sequential access (continued) –Sequential access Does not have unique storage addresses Serial process Data are recorded one after another in a predetermined sequence. Locating an individual item requires searching all of the data until the desired item is located 13 Storage Trade-Offs (continued)

13

Primary storage of your computer Advantages –Small size –Great speed –Shock and temperature resistant Disadvantage –Volatility 13 Semiconductor Memory

Two basic types of semiconductor memory –RAM – random access memory Volatile memory Read/write memory “working” memory 13 Semiconductor Memory (continued)

–ROM – read only memory Nonvolatile Used for permanent storage Can be read but not erased or overwritten –Variations of ROM PROM –Programmable read only memory EPROM –Erasable programmable read only memory 13 Semiconductor Memory (continued)

Most common form of secondary storage Data is recorded on tracks in the form of tiny magnetized spots Thousands of bytes recorded on each track 13 Magnetic Disk Storage

Types of Magnetic Disks –Floppy disks –Zip disks –Hard disk drives 13 Magnetic Disk Storage (continued)

Redundant arrays of independent disks (RAID) –Provides large capacities with high access speeds –Data are accessed in parallel over multiple paths from many disks –Fault tolerant –Storage area networks (SANs) Fiber channel LANs that connect many RAID units 13 Magnetic Disk Storage (continued)

Used as secondary storage Also used in robotic automated drive assemblies Lower-cost storage Archival storage 13 Magnetic Tape Storage

CD-ROM CD-R CD-RW DVD DVD-ROM DVD-RAM 13 Optical Disk Storage

Business applications –Image processing –Provide access to reference materials in a convenient, compact form –videos 13 Optical Disk Storage (continued)

Do you agree with the statement: “The network is the computer”? What trends are occurring in the development and use of the major types of computer systems? 13 Discussion Questions

Do you think that network computers (NCs) will replace personal computers (PCs) in business applications? Are networks of PCs and servers making mainframe computers obsolete? 13 Discussion Questions (continued)

What trends are occurring in the development and use of peripheral devices? Why are those trends occurring? When would you recommend the use of each of the following: –Network computers –NetPCs –Network terminals –Information appliances in business applications 13 Discussion Questions (continued)

What processor, memory, magnetic disk storage, and video display capabilities would you require for a personal computer that you would use for business purposes? What other peripheral devices and capabilities would you want to have for your business PC? 13 Discussion Questions (continued)

The Business Value of PDAs What are the business benefits of PDAs for business applications? What are the limitations of PDAs for business use? 13 Real World Case 1 – City of Richmond & Tim Beaty Builders

References James A. O'Brien; George M. Marakas. Management Information Systems: Managing Information Technology in the Business Enterprise 6th Ed., Boston: McGraw-Hill/ Irwin,