Hardware, Software, Information Technology

Chapter # 1

 

MAHAR Program

Types of Computers

Super computers

سوبر كمبيوتر

Mainframe computers

الحواسيب الرئيسية

Minicomputers

الحاسبات المتوسطة

Microcomputers

الحاسبات الصغرى

 

Supercomputers

High capacity

عالية القدرة

Used by large organizations

التي تستخدمها المنظمات الكبيرة

Tracking space

تتبع الفضاء

Tracking weather

تتبع الطقس

Mainframe Computers

Occupies specially wired, air-conditioned rooms

تحتل خصيصا السلكية ، غرف مكيفة الهواء

 

Capable of great processing speeds and data storage

 

Not as powerful as supercomputers

 

       

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