History of Computers. Counting Man started off by counting on his digits Needed ways to measure...
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Transcript of History of Computers. Counting Man started off by counting on his digits Needed ways to measure...
History of Computers
Counting
Man started off by counting on his digits
Needed ways to measure months and seasons in order to perform festivals and ceremonies
Primitive Calendar
Stonehenge Home for thousands of years to
ceremonial and religious events involving the summer solstice
The Abacus:
The First “Automatic” Computer The abacus first attempt at automating the counting
process. The abacus is not really an automatic
machine it is more a machine which allows the user to remember his current state of calculations while performing more complex mathematical operation.
Forefathers of Computing
Forefathers of Modern Computers
Blaise Pascal
Charles Babbage
Gottfried Wilhelm
The First MechanicalCalculator
Pascal’s Gear System A one tooth gear engages its single tooth
with a ten-teeth gear once every time it revolves; the result will be that it must make ten revolutions in order to rotate then ten-teeth gear once.
This is the way that an odometer works for counting kilometers. The one tooth gear is large enough so that it only engages the next size gear after 1km has passed.
The Difference Engine
Never built Steam-driven Fully automatic Next idea was the Analytical Engine
The Conditional
Babbage’s Conditional The conditional point allows us to check
to see what the current value of “S” is. If “s” is greater than “3”, then we want the computer to output the value of “s” (4 in this case.) If “s” is less than or equal to 3, then we want the computer to output the value “0”
Hermann Hollerith’s Tabulating Machine
This machine was so successful that Hollerith started a firm to market it which later became known as IBM
Binary Representations
Numbers can be converted to decimal to adding together the values of the holes, given that the first hole = 1 and the second 2, etc.
For example, 26=2^5+2^3+2^1+2^0
Holes represent an “on” signal. With 6 holes permissible, 2^6
numbers possible.
Harvard Mark I
Grace M. Hopper working on the Harvard Mark-I, developed by IBM and Howard Aiken. The Mark-I remained in use at Harvard until 1959, even though other machines had surpassed it in performance, providing vital calculations for the navy in World War II.
Alan Turning
Sample Turning Machine Problem: Output a 1 if 3 or more ones
in a row encountered; otherwise )
ENIAC
John Von Neumann
The Von Neumann Machine Data and program can be stored in the same
space. Thus, the machine itself can alter either its program or its internal data.
Conditional goto’s to other points in the code Von Neumann worked with Mauchly and Eckert
on the design for EDVAC Also a contributor to the fields of game theory
and cellular automata
John Von Neumann
EDVAC
Advances in the 1950’s
Transistors Freedom from vacuum tubes, which were
extremely bulky Integrated Circuits
Allowed the placement of many transistors into a small area.
Both these advances enables machines to become smaller and more economical to build and maintain
The Altair
Bill Gates and Paul Allen in 1975 approached Ed Roberts if MITS, the company who developed the Altair, and promised to deliver the BASIC complier.
They did so and from the sale Microsoft was born
Creation of Microsoft
BASIC- Beginner’s All-Purpose Symbolic Instruction Code Developed by Kemeny and Kurtz in
1964. two mathematicians at Dartmouth
Simple, easy-to-understand syntax allowed students to quickly learn it.
Provided ease of programming and easier debugging than machine code or assembly
Other Languages
FORTRAN FORmula Translator Used for science, math, & engineering
PASCAL Developed by Niklaus Wirth in the 60’s Disciplined approach to structure and data
description COBOL
Common Business Oriented Language Data description stored separately from the pgram.
C Derivative of ALGOL It and its decendant’s very popular today for system
programming
The PC Explosion
IBM Acorn released under the unassuming name PC in 1981 1984, 286-AT Whole Host of clones introduced & Compaq releases a
portable Apple
Apple II, 1977 Apple III, 1980 Lisa, 1983; first machine with a mouse and graphical user
interface Macintosh introducted in 1984
Other TRS-80 from Radio Shack 1977 Commodore PET 1980’s 1981, journalist Adam Osborn commissions design of
Osborne I which used CP/M
Bill & Steve Before Microsoft
PCs Today
Fast Graphical User Interfaces (GUI)
Allows you to use a mouse to control the computer
Can run thousands of different sets of instructions (programs)
The Web
The Web can be used for: Looking up information on publications Shopping for books, computers, or CD’s Investigating staff or research at unveristies Downloading pictures, games, or other files/
The Web (World Wide Web) was developed at CERN lab in Zurich, Switzerland/ Requires a client program (such as NetScape
or Lynx) and a server (HTTP) to send information to the client
Internet
New form of communicating 2 things needed to view the internet
Internet connection Browser