lmayer@elgin.edu

Lecture #1
Read: Sections 1.1.and 1.2

Computer History

Early Computing Devices:
16^th & 17^th calculators – John Napier (Napier’s bones-precurser to slide-rule), Wilhelm Schickard, Blaise Pascal (Pascaline), Gotfried Wilhelm von Leibniz (Leibniz wheel) invented calculating devices.

Leonardo Da Vinci may have invented a "calculator" 150 years before these.

Precursors to modern computers:
Joseph-Marie Jacquard invented a loom where the pattern was “programmed” using punched cards.

Charles Babbage received a grant from the British government to build a Difference Engine to calculate navigational tables, etc. He designed an Analytical machine using punched cards. Machine was pre-cursor to modern computer: had input, processor, memory and output, but was never built.

Lady Lovelace, the first programmer, wrote programs for the Analytical machine.  Came up with ideas of subroutine, loop and conditional jump.

1890:Herman Hollerith won a contest for easier way to process/calculate census data.  His machine used an Automatic Card reader.  He formed what later became the International Business Machines company, or IBM as we know it today.

The war years:
Konrad Kruse built the first electronic computers, Z1 and Z2, and unsuccessfully tried to interest the Nazi government.

Polish secret service stole German machine, the ENIGMA, used to encrypt communications.  British secret service group (containing Alan Turing) formed to decipher German codes encrypted by Enigma machines, built the Colossus the first all-electronic digital machine.  Colossus used vacuum tubes.

The Mark I, built by IBM scientists, Harvard University and the U.S. War Dept., used relay switches instead of vacuum tubes. This machine made defense calculations for the U.S. Navy.

U.S. Army built the ENIAC (Electronic Numerical Integrator and Calculator) to calculate projectile trajectories.

These very large computers had very small memory capacity and limited programmability.

The stored program concept:
John Von Neumann, a member of the Eniac team, solved the problem of limited programmability by giving machines. instructions using binary code.

The UNIVAC (Universal Automatic Calculator) was one of these stored-program computers.  One was bought by the General Electric company which was the start of computers in business.

Miniaturization:
Transistor Age – with the invention of transistors, computers (as well as TVs, radios, etc.) could be made smaller, more reliable and use less electricity. This was the birth of the still large mainframe computers.  Still using punchcards.

Birth of the home computer:
By the mid 70s, computer hobbyists were able to build their own small computers.  One of the most popular being the ALTAIRComputer.

In 1976, Steve Jobs and Steve Wozniak, built the Apple II computer which had keyboard entry, displayed text and color and could be programmed in BASIC.

Internet:
Advanced Research Projects Agency (Dept. of Defense) created ARPANET to allow scientists to collaborate and exchange info. Connected UCLA, UC Santa Barbara, Stanford, U. of Utah