Getting Started, Part 1

Objectives

When we complete this section, you should be able to:

Describe the components of a computer system.
Define the terms used to measure the capacity and speed of a microprocessor, memory and storage
Describe the contributions of IBM, Microsoft, and Intel in the evolution of the PC
Discuss consideration in the purchase of a computer system.
Distinguish between system software and application software

Some History

Look up the definition for computer at www.webster.com.
Analog vs Digital
- What is an analog clock?
- What is a digital clock?
- What is the difference?
- Which is more accurate? Trick question.
- Which can be read more accurately.
- analog representing data by a physical quantity
- digital representing data as a number.
- Think of a flood gage, or rain Gage.
- Think of a ruler, 14 and 3/16 + a little bit.
the first computers were analog.
- Fingers, stones, bones, ...
- Abacus
- computer an electronic device that accepts data, processes that data to produce information. It operates under the control of a program that is stored internally within the computer's memory.
- Why do the above devices fail to meet this definition?
Charles Babbage
- Difference Engine/ Analytical Engine
- An analog computer
- Almost built in the late 1800's
- Could store both data and program.
- Store up to 1,000 numbers.
- Consisted of around 50,000 components.
- Failed because technology was not equal to theory.
- They built one.
- I enjoyed the book "The DIfference Engine", but perhaps it is not for everyone.
Modern electronic computers
- Were first built in the lat 1940's
- Have been through a number of "generations"
  - 0th generation - electro-mechanical
    - John Atananoff
    - at Iowa State
  - 1st generation - vacuum tubes
    - First at University of Pennsylvania
  - 2st generation - transistors
  - 3rd generation - Inetgrated Circuit or microchip
  - 4th generation - Very Large Scale Integration (VLSI)
  The general trend is to be:
  - Smaller
  - Cooler
  - Less Expensive
  - More reliable
Computers once were classified by size
- Microcomputers: Up to $5,000. Personal use.
- Workstations: $5,000 - $100,000. Scientific Calculations Sun Workstation
- Minicomputers: $100,000 - $500,000. Division Data Processing IBM i-series
- Mainframes: $500,000 and up. Used for Corporate Data Processing Fujitsu
  - Requires 16 sq ft of space (minimum)
  - 2,200 pounds (minimum)
  - Can be liquid cooled.
  - 2 - 64 gb memory
- Super Computers psc
- These are really no longer valid.

Most Computers

Can be broken into a number of parts
- CPU - Central Processing Unit
- Memory - RAM (Random Access Memory)
- Secondary Storage (The hard drive)
- Input Devices (keyboard, mouse ...)
- Output Devices (Monitor, printer)

Representing Data Digitally

We use a base 10 number system, digits 0 -9
Computers use base 2, digits 0 and 1.
Why?
A single Binary Digitt is called a bit
8 bits form a byte
About 1000 bytes for a kilobyte or 1K
About 1 million bytes form a megabyte or 1M (meg)
About 1 billion bytes is a gigabyte or 1G (gig)
Look at the Wikipidia Entry for more information.
Some Example Files.
Characters are encoded using ASCII Americal Standard Code for Information Interchange.
Letter ASCII Code

A 0100 0001

B 0100 0010

C 0100 0011

Letter	ASCII Code
A	0100 0001
B	0100 0010
C	0100 0011

Example
      Dan is
      0100 0100 0110 0001 0110 1110 
          D         a         n

Parts of a PC

Some History First
- 1975 ALTAIR computer kit, build it your self.
- 1976 First APPLE I introduced.
- 1977 Tandy and Commodore begin selling pcs.
- 1977 Microsoft founded.
- 1978 Intel introduces the 8086
- 1981 IBM begins selling IBM PC
- 1982 IBM Clones begin arriving, Compaq is an early player
- 1985 Intel introduces the 80386
The Parts
- Take a look at www.motherboards.com
- Motherboard - this is the frame on which everything is put.
  - Directly attached is the processor, chip or CPU Central Processing Unit.
    - Measured in Gigahertz
    - 1 to 2 GHz
  - Main Memory is also directly attached.
    - Measured in Megabytes
    - 128 is a minimum
  - It has a number of expansion slots where other devices (modems, sound and graphics cards, ...) can be attached.
- A hard drive (or several) are plugged into the motherboard
  - Measured in gigabytes
  - 10 - 80 is standard
  - 10 is probably low today
- There are a number of drives that support removable media
  - Floppy Drive
  - zip drive
  - CD player
  - DVD player
  - Tape Drive for backup
- The motherboard is mounted in a case, which contains a
  - Power supply
  - Fans
  - Space to mount all of this stuff.
- A number of cards can be plugged into the expansion slots or their functionality can be built into the motherboard.
  - A video card or graphics card goes into the AGP slot
  - sound card
  - modem
  - LAN card or network card
  - Many specialized cards
- There are a number of I/O devices that attach externally to the machine.
  - Monitor
  - Keyboard
  - Mouse
  - Printer
  - Joystick
A word about the CPU
- CPUs are manufactured by different companies
  - INTEL
  - AMD
  - HP
  - And Others
- CPUs are in different families
  - Pentium
  - Celeron
  - Xeon
  - PA-Risc
  - and others
- You can't compare CPUs from different families directly
- CPUs have a speed that they operate
  - This is in megahertz
  - This is millions of cycles per second
  - Currently up to 2 Gigahertz are supported
  - This is equivalent to 2 billion instructions per second
  - Add, get from memory, write to memory ...
- Moore's Law Performance will double every 18 months.
  - Stated in 1965
  - Has held true since then.
  - Means that things become obsolete very quickly.
  - Programs expect to have more processing power available to them
  - If you build it, they will come (or use it as the case may be)

Purchasing a PC

You have a large number of choices
- Purchase from someone like Dell or Gateway .
- Purchase from a local company.
- Radio Shack, Sears ...
- Buy the pieces and build it yourself.
You should consider support options as well.
- Warranty
- User support
Take a look at
- dell.com
- motherboards.com