Definition of a Computer
Simplest definition of a computer: A device that processes input and generates output

Key words:

Modern Computers are electronic, complex, and interactive, but can be reduced to simple input-output processing devices

 

History of Computers: 3000 BC to Present

History of Computers - Long, Long Ago
The Abacus

  • beads on rods to count and calculate
  • still widely used in Asia!

 

History of Computers - Way Back When
The Slide Rule 1630

  • based on Napier’s rules for logarithms
  • used until 1970s

 
 

History of Computers - 19th Century
Jacquard Loom

  • used metal cards with punched holes to guide weaving process
  • first stored program - metal cards
  • first computer manufacturing
  • still in use today!

 
 

Charles Babbage - 1792-1871
Difference Engine c.1822

  • huge calculator, never finished
Analytical Engine 1833
  • could store numbers
  • calculating "mill" used punched metal cards for instructions
  • powered by steam!
  • accurate to six decimal places
Babbage's Analytical Engine


Ada Augusta - First Programmer


Discussion Question

Vacuum Tubes - 1930 - 1950s

  • First Generation Electronic Computers used Vacuum Tubes
  • Vacuum tubes are glass tubes with circuits inside.
  • Vacuum tubes have no air inside of them, which protects the circuitry.
UNIVAC - 1951
  • First commercially available computer
  • sold to censu bureau
  • "a big pocket calculator"
  • until 1970 was standard computer, but very expensive
  • http://www.letsfindout.com/subjects/space/univac.html

Grace Hopper

  • Programmed UNIVAC
  • Recipient of Computer Science’s first "Man of the Year Award"
  • http://www.ce.vt.edu/evd/Htmls/P375994.html

First Computer Bug - 1945

  • Relay cards carried information
  • Grace Hopper found an actual moth stuck to card responsible for a malfunction
  • Called it "debugging" a computer
First computer bug is a moth

First Transistor

  • Uses Silicon
  • developed in 1948
  • won a Nobel prize
  • on-off switch
  • Second Generation Computers used Transistors, starting in 1956


Integrated Circuits
 

  • Third Generation Computers used Integrated Circuits (chips).
  • Integrated Circuits are transistors, resistors, and capacitors integrated together into a single “chip”

 

Birth of Personal Computers -

Kenbak I - 1971

  • Very primitive, just flashing lights and buttons
  • about $750

MITS Altair - 1975 (pictured)

  • 256 byte memory
  • 2 MHz Intel 8080 chips
  • Just a box with flashing lights
  • cost $395 kit, $495 assembled.

 

The First Microprocessor - 1971
 

Inside the Intel 4004 Microchip - 2250 Transistors
Inside the Intel 4004 - 2250 Transistors
 

Generations of Electronic Computers
Generation First

Generation

I

Second Gen.

II

Third Gen.

III

Fourth Gen.

IV

Technology Vacuum Tubes Transistors Integrated Circuits (multiple transistors) Microchips (millions of transistors)
Size Filled Whole Buildings Filled half a room Smaller Tiny - Palm Pilot is as powerful as old building sized computer

 
 

Over the past 50 years, the Electronic Computer has evolved rapidly.

IBM PC - 1981

Apple Computers

1990s: Pentiums and Power Macs


   

How Electronic Computers Have Progressed
 
 
UNIVAC

(1951-1970)

(1968 vers.)

Kenbak 1

(1971)

IBM PC

(1981)

Macintosh

(1984)

Pentium III
Circuits Tubes,

Transistors, Integrated Circuits*

130 Integrated Circuits Intel 8088

Microchip - 29,000 Transistors

Motorola 68000  Intel P-III

Microchip - 7.5 million transistors

Generation I-II-III* III IV IV IV
RAM Memory 512 K 265 Bytes 256 K 640 K 128 Mb
Speed 1.3 MHz 1 KHz 4.77 Mhz 8 MHz 1000 MHz
Storage 100 MB Hard Drive none Floppy Drive Floppy Drives Hard Drive, Floppy, CD-Rom
Size Whole Room Briefcase

(no monitor)

Briefcase + Monitor Two shoeboxes (integrated monitor) Small Tower
Cost $1.6 million $750 $1595 ~$4000 $1500

*Early UNIVACs had vacuum tubes, middle models had transistors, and by the end they used integrated circuits
 

What’s next for computers?