Information Systems Hardware Chapter 2 Chapter Objectives Understand

Information Systems Hardware Chapter 2

Chapter Objectives • Understand the important role of IS hardware in the success of modern organizations • Describe key elements of IS hardware • List and describe the types of computers used in organizations today • Explain how hardware has evolved and where it is headed

The Importance of Information Systems Hardware • Used in a rapidly changing, highly competitive global economy • Relied upon for the exchange of realtime information • Used on a daily basis for work, school, and fun

Key Elements of Information Systems Hardware

Input: How Information is Entered into an Information System • The type of information determines how it is input – Text, numbers – Drawings, designs – Audio, video

Entering Original Text / Numbers • Keyboard is most common entry device • Advanced keyboards are ergonomically designed

Selecting and Pointing • • • Mouse - most common pointing device Trackball Joysticks Touch screens Light pens

Entering Batch Data • Used for entering large amounts of routine information • Scanners – Convert printed text and images into digital data • Text recognition software – Convert handwritten text to digital data • Bar Code/Optical Character Readers – Use light to scan magnetic data

Audio and Video • • Microphone Digital cameras Videocassette recorders

Processing: Transforming Inputs into Outputs • All input must be converted into computer readable format • Internal processing uses binary notation – Binary consists of a series of 0’s and 1’s – Each 0 or 1 is a bit – A combination of eight bits is a byte • ASCII represents numbers and letters in binary code

Key Processing Elements • Central Processing Unit (CPU) – Interprets and executes commands – Controls movement of data • Primary storage – Current • Secondary storage – Permanent

Figure 2. 10

Primary Storage: Storage for Current Information • Nonvolatile – ROM (Read Only Memory) • Holds instructions to start up the computer • Volatile – RAM (Random Access Memory) • Stores data and program instructions the CPU is currently working on – Cache Memory • Fast RAM for instructions queuing for immediate processing by the CPU

Elements of Computer Storage

Secondary Storage: Keeping Information for Later Use • Permanent storage of data and programs – Magnetic tape – Floppy disks – Fixed disks – Compact discs – Optical disks

Magnetic Tape • Same medium as audio cassette tapes • Data stored by magnetically rearranging atoms on tape • Uses sequential data access • Primarily used for backing up large amounts of data

Floppy Disks • • • Small magnetic disks Transfer data between computers Use direct data access (random access) 2. 5” disk holds 1. 44 MB Iomega’s ZIP disk can store 100 MB

Fixed Disks • Several magnetic platters in a sealed container • Read/Write heads for each platter surface • Greater storage capacity and data transfer rate than floppy disks

CD-ROM (Compact Disc Read-Only Memory) • • • Uses the same technology as audio CD Uses direct access Holds 650 MB Slower than fixed disk CD-R (CD-Recordable) drives available

Optical Disks • Similar to CD-ROM technology • May be rewritten many times • Storage capacity of over 1 gigabyte (GB) on a single disk • Disks and disk players relatively expensive

The Central Processing Unit: The Brain of the Computer • • Calculates and manipulates data Composed of millions of transistors Operates on electronic impulses Can perform more than a million instructions per second

Output: How Information is Displayed and Printed • Output types are limited – Video output – Printer – Sound

Video Output • Monitors – Most common video display – Uses a cathode ray tube (CRT) • Liquid crystal display (LCD) – Used in portable computers • Monitors embedded in many other devices

Paper-Based Displays • Printers – Dot-matrix: form letters using a series of small dots – Inkjet: spray ink on paper from a small cartridge – Laser: use an electrostatic process to burn ink to the paper • Plotters – Transfer designs to drafting paper

Audio Output • Uses small speakers and a sound card • Translates digitized data into sound

Types of Computers • • • Supercomputers Mainframes Minicomputers Workstations Microcomputers

Supercomputers • The most powerful and expensive computers • Contain numerous very fast processors that work in parallel • Used by researchers and scientists to solve very complex problems • Cost more than 1 million dollars

Mainframes • The backbone of large corporate computing • The only type of computer that existed 30 years ago • Used for enterprise-wide computing

Minicomputers • Scaled down versions of mainframes – Smaller – Less expensive • Declining market due to faster and more powerful microcomputers

Workstations • The power of a minicomputer on a desktop • Leaders in the market – Silicon Graphics – Sun Micro Systems – DEC • Process intensive applications – Computer-Aided Design (CAD) – Web Servers

Microcomputers • • Often called personal computers Desktop models Portable computers Most commonly used computing technology for knowledge workers

Evolution of Information Systems Hardware • Shifts in computing eras facilitated by changes in computing technology • Evolution marked by significant events creating four generations of hardware

The First Generation: Vacuum Tubes • 1946 - 1958 • ENIAC: one of the first computers – 1946 – Room-size with 18, 000 vacuum tubes • Replaced in 1950 by the UNIVAC • Mainframe era begins

The Second Generation: Transistors • 1958 -1964 • Transistors generate less heat • Transistors are smaller, faster, and more reliable • First transistors smaller than a dime • Mainframe era continues

The Third Generation: Integrated Circuits (IC) • • 1964 -1990 Multiple transistors on a single chip IBM 360 - First mainframe to use IC DEC PDP-11 - First minicomputer 1975 - Altair 8800 first microcomputer 1981 - IBM introduced the PC End of mainframe era, through mini era to personal computing era

The Fourth Generation and Beyond • 1990 - Present • Radical new applications – Multimedia: the integration of voice, video and data – Internet for video conferencing – End-user computing

The Future of Information System Hardware • Will continue the trend of smaller, faster, cheaper and ubiquitous • Virtual Reality • Wearable Computing • Smart Cards