computer basics notes

							Computer Basics
 Computer Technology
          What is a Computer
 Information   Processor
 Input
 Output
 Processing
 Storage


    physical parts like monitor, mouse,
 Are
 keyboard essential?
               Computer History
   Abacus
       3,000 B.C.
                Computer History
 Jacquard Loom-
  1801
 First “program”
       Stored on metal
        cards
       Used in
        manufacturing
       Still used today
               Computer History
 Charles Babbage
  1792- 1871
 Analytical Engine-
  1833
       Could store numbers/
        do math
       Programmed by metal
        punch cards (software
        )
       Powered by steam,
        had gears and levers
             Computer History
     was the biggest advance that led to
 What
 modern computers?
     Electricity
       • Transistors
       • Microchips
       • Data storage
               Computer History
   Vacuum Tubes- 1941-1956
       First generation electronic
        computers
       Vacuum Tubes are glass tubes
        with circuits inside
            Computer History
 UNIVAC/    ENIAC
     Programmed by rewiring
     Weighed 30 tons
     Contained 18,000
      vacuum tubes
     Cost $487, 000
           Computer History
 Grace Hopper
 Recipient of
  Computer Science’s
  first “Man of the Year
  Award”
 Programmed UNIVAC
            Computer History
   First Computer Bug   • Grace Hopper found a
                           moth stuck in a relay
                           responsible for a
                           malfunction
                         • Called it “debugging” a
                           computer




                         • What are today’s
                           computer “bugs”?
            Computer History
 Transistors   replaced vacuum tubes-
 1950’s
     Made computers smaller and more reliable
            Computer History
•Third Generation Computers used
Integrated Circuits (chips).
•Integrated Circuits are transistors, resistors,
and capacitors integrated together into a
single “chip”
•Circuits are transistors, resistors, and
capacitors integrated together into a single
“chip”
               Computer History
   1950’s Transistors replaced vacuum tubes in
    computers.
       Made computers smaller and more reliable.
   1940’s – 1950’s- Computer Programming
       Moved from rewiring to change function of a computer
        to applications used to solve problems.
 1970’s- IBM and other manufactures had
  computers in most companies and universities
 1980’s- Computer changed from large tool only
  for experts to a product for the general
  consumer.
          The Personal Computer
   Apple Corporation founded in mid 1970’s.
       Steve Jobs and Steve Wozniak
   Bill Gates of Microsoft- developed DOS (Disk
    Operating System).
       1981- Became Operating System for IBM PC’s.
       Became the “standard” operating system.
 Students who graduated from high school or
  college before 1985 seldom had access to
  personal computers.
 End of 1980’s- many schools had computer labs
 Personal Computer Hardware
 Hardware-     Physical components
     Power Supply- distributes electricity. Has a
      fan to cool internal components.
     CPU- Central Processing Unit- “brains” of the
      computer. Tells all parts of computer what to
      do. Performs calculating and logic functions.
     Motherboard- Largest circuit- contains
      expansion slots for additional circuits
      (graphics card, etc.)
              Peripherals
 Device  connected to the computer through
  the BUS.
 Monitor, keyboard, printer, mouse.
 Video cards, modems, and sound cards
  are inside the computer.
 Peripherals are generally Input or Output
  devices.
                 Peripherals
         Most PC’s use a Cathode Ray
 Monitor-
  Tube (CRT) similar to the tube in a TV.
     Laptops and flat screens use a Liquid Crystal
      Display (LCD) in their monitors.
 Hard   Drive/ CD- ROM Drive/ Disk Drive
     Both Input and Output
 Printers-   we use a laser printer
              Bits and Bytes
 Computers   operate through on/off
  switches called bits.
 Bits are grouped into bytes.
     Ex: A on keyboard = 01000001.
     Byte is most common unit of measurement.
                  Software
 Instructionsthat allow a computer to run
  and act on the data given as input.
  Software = Programs
 Two Types
     Operating System
     Application
        Operating System/ Processing
                  Software
   Most important software program.
       Allows a computer to start up.
       Controls how the CPU operates and communicates.
       Makes computers user friendly.
       We use Windows Vista
         • Graphical User Interface- allows us to use mouse and icons
           to use computer. We don’t need to know commands or
           programming language.
         • Older operating systems- DOS- had to type in commands for
           EVERYTHING.
 Application/ Program Software
         programs that allow you to make
 Includes
 the computer do what you want.
     Ex: Word- write a letter, Dreamweaver- build
      a web page.
     Applications that run on one operating system
      will not run on a different operating system.
       • Ex: Windows can’t run on Unix of MacOS.
     Personal Computer Memory
   RAM- Random Access Memory- used for active
    processing.
       Ex: When you start Excel, the computer places the
        program in RAM. When you open a document, it is
        also placed in RAM.
       When you save, the CPU copies the document from
        RAM to permanent storage (ROM). When you save
        and close memory is freed up.
       RAM holds information only when there is electricity.
        When machine is turned off/ loses power, whatever is
        in RAM is also lost.
  Personal Computer Memory
 ROM-  Read only memory
 ROM preserves its contents even when
  the computer is shut down.
 ROM stores programs
 When you open a program it moves from
  ROM to RAM.