Operating Systems &
History of Computers
Computer Technology
Linda Brown
Presentation 3
How the Computer Evolved
1642 Blaise Pascal – mechanical adding
machine -- Gears Only –- jammed a lot
Early 1800’s Joseph Jacquard French
Weaver – used punch cards to control the
pattern of the weaving loom (needles passed
through the holes and picked up the threads. By changing the
card, pattern could be changed without stopping machine.)
1832 Charles Babbage - invents the
Difference Engine (Was supposed to keep tables of data
for ships navigators. Had errors often and many ships lost at
sea.)
1890 Herman Hollerith – invents a machine
using punch card to tabulate info for the
Census (used to take 9 years to calculate by hand; This
machine decreased that time to 6 weeks. Used electricity
instead of gears to perform the calculations)
Hollerith’s Tabulating Machine
1st Generation computers
Used vacuum tubes.
Vacuum tubes are
electronic devices that
control the flow of
electrons.
Had no operating
systems.
Used custom
application programs,
which were made for
the specific task that
the computer was to
perform.
Instructions were
necessary for every
aspect of the
computing job.
ENIAC Computer - 1946
First Electronic Computer
Miles of wiring
18,000 vacuum tubes
Thousands of resistors and
switches
No monitor
3,000 blinking lights
Cost $486,000
100,000 additions second
Weighed 30 tons
Filled a 30x50 foot room
Given a problem it should
have taken mathematicians
3 days to complete. Solved
the problem in 20 seconds.
Could be replaced today by
one fingernail-size silicon
chip
2nd Generation computers
Used transistors.
Transistors performed
functions similar to vacuum
tubes, but they were
smaller, cheaper, less
power-hungry, and more
reliable.
Ran programming
language compilers.
Used English like
commands rather than
binary numbers.
Made it possible to develop
software.
Punch cards replaced by
magnetic tape. Now
computers could read
and write to the tape.
3rd Generation computers
Used integrated circuits.
One IC could replace hundreds of
transistors.
Tremendous speed
Millions of calculations per second
Mainframes mostly but some
minicomputers introduced.
Smaller and less powerful than 1st
and 2nd generation computers, but
had the ability to run multiple
programs for multiple users
simultaneously.
4th Generation computers
Used general-purpose microprocessors
Computer systems were smaller,
faster, and less expensive than 3rd
generation computers.
1970’s – Integrated circuits and silicon
chips lead to smaller microprocessors
Operating System Software
Master controller for all activities that take
place within a computer; primary purpose
is to help the computer system monitor
itself in order to function efficiently.
Interacts with application software, device
drivers, and hardware to manage a
computer’s resources.
Ensures that input and output proceed in
an orderly manner.
Platform
Underlying hardware and software of the
computer system.
Two popular platforms
PC
Mac
GUI (Graphical User Interface)
A type of user interface that features on-
screen objects, such as menus and icons,
manipulated by a mouse.
Abbreviation is pronounced “gooey”.
Multitasking
Running more than one program at a time.
Programs can be minimized but still running in
the background and are placed on Task Bar.
Making sure that the instructions and data
from one area of memory don’t interfere
with memory allocated for other programs.
Program
Setof detailed, step-by-step instructions that tell a
computer how to solve a problem or carry out a task.
Application Software
Set of computer programs that help a person carry out a
task. (major types listed below)
Word Processing – used to type letters, reports, memos
Spreadsheet – used for numeric calculations, budgets, charts,
graphs
Presentation – used to combine text, graphics, animation, charts,
and graphs into a series of electronic slides for presentation
purposes
Database – retains information for quick access and sorting.
Used when large amounts of information need to be stored, found
organized and reported.