Hardware, Software, Information Technology

Chapter # 1

MAHAR Program

Types of Computers

Supercomputers

Mainframe Computers

•       

Minicomputers

•      Known as midrange computers

•      Medium-size companies

•      Used by departments of large companies

Network Computer

Network Computer

Network Computer

Terminals

•      An input and output device

•      Connects to a mainframe or server

•      Types of terminals

–  Dumb terminal

–  Intelligent terminal

–  Network terminal

–  Internet terminal

Microcomputers

•      Least powerful

•      Widely used

•      Four types

–  Desktop

–  Notebook or laptop

–  Tablet PC

–  Handheld

Microcomputer Hardware

•      System unit

•      Input/output devices

•      Secondary storage

•      Communications

System Units
Microcomputers

•      Desktop

•      Notebook

•      Tablet PC

•      Handheld

System Board

•      Connects all components

•      Allows communication between devices

•      Main board or motherboard

•      Circuit board                                                  electronic components

–  Sockets

–  Slots

–  Bus lines

Microprocessor

•      Central Processing Unit (CPU )

 

•      Two basic components

–   Control unit

–   Arithmetic and logic unit

Specialty Processors

•      Graphics coprocessors

 

•      Parallel processors

 

•      Smart cards

Memory

•      Holding area for data, instructions, and information

•      Types of memory chips

–  RAM – holds programs and data

 

–  ROM – fixed start-up instructions

 

–  CMOS – flexible start-up instructions

Memory Capacity

System Clock

•      Important measurement indicating speed

–  Located on a small chip

–  Produces electrical beats

•      Synchronizes operations

•      Expressed in gigahertz

•      Faster clock speed, faster computer

Expansion Slots and Cards

•      Allow for new devices to be added

–  Open architecture

–  Slots provide for expansion

•      Expansion cards are also called …

–  Plug-in boards

–  Controller cards

–  Adapter cards

–  Interface cards

Commonly Used Expansion Cards

•      Video cards

•      Modem cards

•      Network interface cards (NIC)

•      TV tuner cards

•      PC cards

Bus Lines

•      Connect parts of the CPU to each other

•      Data roadway for traveling bits

–  Measured as bus width

–  More lanes, faster traffic

•      Two basic categories

–  System buses

–  Expansion buses

Ports

•      Socket for connecting external devices

•      Four common ports

–  Serial

–  Parallel

–  USB

–  FireWire

Power Supply

•      Computers require direct current (DC)

•      DC power provided by converting alternating current (AC) from wall outlets or batteries

•      Desktop computers use power supply units

•      Notebooks and handhelds use AC adapters

What is Input?

•      Any data or instructions used by a computer

•      Input devices

–  Hardware

•   Keyboards

•   Mice

•   Scanners

•   Other devices

–  Translates data into a form that the system unit can process

Keyboard Entry

•      Keyboards

–  Traditional keyboards

•   Flexible keyboards

•   Ergonomic keyboards

•   Wireless keyboards

•   PDA keyboards

–  Features

•   Typewriter keyboard with numeric pad

•   Special purpose keys

•   Toggle and combination keys

Traditional Keyboard

Pointing Devices

•      Mouse

–  Mechanical

–  Optical

–  Cordless                                                                                          or wireless

•      Joystick

•      Touch Screen

•      Light Pen

Scanning Devices

•      Optical scanners

–  Flatbed

–  Portable

 

•      Bar code readers

–  Handheld wand readers or platform scanners

–  Contain photoelectric cells that read bar codes

Scanning Devices

•      Character and mark recognition devices

•      Scanners that recognize special characters & marks 

–  Magnetic ink character recognition (MICR)

–  Optical-character recognition (OCR)

–  Optical-mark recognition (OMR)

Image Capturing Devices

•      Digital camera

–  Images recorded digitally on a disk

–  Images can be downloaded to a computer

•      Digital video camera

–  Records motion digitally

–  Can take still images as well

–  WebCams

•   Specialized digital video cameras

•   Broadcast images over the Internet

Digitizing Devices

•      Graphics Tablets

 

•      Digital Notepads

Audio Input Devices

•      Voice

–  Voice recognition systems

•   Discrete-speech recognition systems

•   Continuous-speech recognition system

–  Music

•   Musical Interface Digital Interface (MIDI)

What is Output?

•      Processed data or information

•      Types of output

–  Text

–  Graphics

–  Audio & video

•      Output devices

–  Monitors

–  Printers

Monitors

•      Known as screens or display screens

•      Output referred to as soft copy

•      Features

–  Resolution

–  Dot pitch

–  Refresh rate

–  Size

More on Monitors

•      Cathode-ray tube or CRTs

•      Flat-panel

–  Liquid crystal display (LCD)

–  Portable and thinner than CRTs

•      Other monitors

–  E-books

–  Data projectors

–  High-definition television (HDTV)

Printers

•      Translates information that has been processed by the system unit

•      Output referred to as hard copy

•      Features

–  Resolution

–  Color capability

–  Speed

–  Memory

Printers

•      Ink-jet printer

•      Laser printer

–  Personal laser printers

–  Shared laser printers

•      Thermal printer

•      Other printers

–  Dot-matrix

–  Plotters

–  Photo printers

Audio Output Devices

•      Translates audio information into sounds that people can understand

•      Common devices

–  Speakers

–  Headphones

Combination  Input and Output Devices

•      Fax machines

•      Multifunction devices

•      Internet telephones

–  Telephony

–  Voice-over IP (VoIP)

•      Terminals

Secondary Storage

•      Floppy

•      Hard disk

•      Optical disks

Storage

•      Primary storage

–   Volatile

–   Temporary

Secondary Storage Devices

Floppy Disks

•      Diskettes

•      Floppies

•      Portable storage media

•      Floppy disk drives (FDD)

Traditional Floppy Diskette

Types of Floppies

•      High capacity

•      Known as a floppy-disk cartridge

•      Require special disk drives

•      Three well known types

–  Zip disks 

–  HiFD disks 

–  SuperDisks

Hard Disks

•      Use thicker, metallic platters for storage

 

•      Faster than a floppy diskette

 

•      Large capacity

 

•      Sensitive instruments

Materials that Cause a Head Crash

Internal Hard Disk

•      Located inside system unit

•      Known as a fixed disk

•      Designated as the C drive

•      Advantages over floppies

–  Access speed

–  Capacity       

Hard-Disk Cartridges

•      Removable hard disks

•      Used to complement internal hard disk

•      Capacities of 10 to 20 GB

Hard-Disk Packs

•      Removable

•      Massive storage capacity

•      Common in mainframes

•      Resembles stack of vinyl records

Hard-Disk Pack

Performance Enhancements

•      Disk caching

 

•      Redundant arrays of                                                 inexpensive disks (RAID)

 

•      File compression                                                                            and decompression

Optical Disks

•      Compact

•      Permanent storage

•      Laser beams reflect off pits

•      Two common types

–  CD

–  DVD

Compact Disc

•      Optical format

•      From 650 MB to 1 GB capacity

•      Rotation speeds vary

•      Types

–  Read only: CD-ROM

–  Write once: CD-R

–  Rewriteable: CD-RW

–  Picture CDs and Photo CDs

Digital Versatile Disc

•      Digital Versatile Disk or Digital Video Disk (DVD)

•      Similar to CDs, but can store more data

•      Types

–  Read only

–  Write once

–  Rewritable

DataPlay

•      Optical disk

•      Write once format

•      Quarter size

–  500 MB capacity

–  Holds 5 hours of CD-quality sound

•      Use for storing and playing music files

Other Types of Secondary Storage

•      Solid-state storage

 

•      Internet hard drives

 

•      Magnetic tape

Solid-State Storage

•      Flash memory cards

–  Widely used in notebook computers

–  Used to record MP3 music files

•      Key chain hard drives

–  Key chain flash memory                                            devices

–  Connects to a USB port

Internet Hard Drives

Magnetic Tape

•      External storage

•      Provides sequential access

–  Information stored in sequence

–  Slower than disks which provide direct access

•      Magnetic tape streamers or tape cartridges used by both mainframes and microcomputers  

Computer Performance

Connectivity, the Wireless Revolution, and the Internet

•      Connectivity

–  Sharing of information

–  Wireless communication is becoming popular

•      Computer networks

–  Connected communication system of computers

–  Largest network is the Internet