```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
Charles Babbage
Gottfried Wilhelm
Blaise Pascal
The First Mechanical
Calculator

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
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
surpassed it in
performance, providing
vital calculations for the
navy in World War II.
Alan Turing

Sample Turing 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

Transistors


Freedom from vacuum tubes, which
were extremely bulky
Integrated Circuits


Allowed the placement of many
transistors into a small area.
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



PASCAL



FORmula Translator
Used for science, math, & engineering
Developed by Niklaus Wirth in the 60’s
Disciplined approach to structure and data
description
COBOL



C


Data description stored separately from the pgram.
Derivative of ALGOL
It and its decendant’s very popular today for
system programming
The PC Explosion

IBM




Apple





Acorn released under the unassuming name PC in 1981
1984, 286-AT
Whole Host of clones introduced & Compaq releases a
portable
Apple II, 1977
Apple III, 1980
Lisa, 1983; first machine with a mouse and graphical user
interface
Macintosh introducted in 1984
Other



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
universities
files/
The Web (World Wide Web) was
developed at CERN lab in Zurich,
Switzerland
Internet


New form of communicating
2 things needed to view the internet


Internet connection
Browser
```