Transcript ThE fOuR gEnEraTioNs oF dIgiTaL CoMputEr

The four generations of
digital Computer
1. The first generation computers
2. The second generation computers
3. The third generation computers
4. The fourth generation computers
First Generation Computers
(1951-1958)
The
first
generation
of
computers used vacuum tubes as their
main logic elements; punched cards to
input and externally store data; and
rotating magnetic drums for internal
storage of data in programs written in
machine
language (instructions written as a
string of 0s and 1s) or assembly
language (a language that allowed the
programmer to write instructions in a
kind of shorthand that would then be
"translated" by another program called
a compiler into machine language).
In 1945, Presper Eckert and John
Mauchly developed the first operational
electronic
digital
computer, called
ENIAC, for US Army. ENIAC was over
1000 times faster than Mark 1, and
could perform 5000 additions per
second.
ENIAC had more than 1800 vacuum
tubes, and took up to 1800 square feet
of space. In addition, the electrical
current ENIAC required could power
more
than
a
thousand
modern
computers. Today, ENIAC’s technology
could fit in a modern wristwatch.
In 1951 the UNIVAC-1 became the first
commercially
available
electronic
computer. This computer was designed by
Eckert and Mauchly (the designers of the
ENIAC) and built by the Remington Rand
corporation. The first of these computers
was delivered to US. Census Bureau.
Between 1951 and 1953 magnetic
core memory was developed. This
memory consists of
tiny ferrite
“donuts” that were arranged on a
lattice of wires. The polarity of their
magnetization could be change or
detected by passing current through the
wires. This allowed each lattice point store
one “bit” – either 0 or 1. Magnetic core
memory was the fastest type of memory until
the late 1980’s. through the wires. This
allowed each lattice point store one “bit” –
either 0 or 1. Magnetic core memory was the
fastest type of memory until the late 1980’s.
Second Generation Computers
(1959-1963)
In the 1940s, discovered that a class
of crystalline mineral materials called
semiconductors could be used in the
design of a device called a transistor to
replace vacuum tubes. Magnetic cores
(very small donut-shaped magnets that
could be polarized in one of two
directions to represent data) strung on wire
within the computer became the primary
internal storage technology. Magnetic tape and
disks began to replace punched cards as
external storage devices.
High-level programming languages
(program instructions that could be
written with simple words and
mathematical
expressions),
like
FORTRAN
and
COBOL,
made
computers more accessible to scientists
and businesses.
Instead of vacuum tubes, second
generation computers used transistors
an exiting new invention at the time.
John Barden, Walter Brattain and
William Shockley of Bell Telephone
Laboratories invented the transistor. A
transistor is a small, solid-state
component designed to monitor the flow
of the electric current.
Core memory stack
Tiny magnetic doughnuts.
Transistor
Were smaller, faster, cheaper,
required less power, and produce less
heat than vacuum tubes. In computers,
a transistor functions as an electronic
switch or bridge. Transistors play an
important role in electronic circuits.
Circuits help make up electronic
systems, and electronic systems are
what make electronic computing
possible. Transistors allowed
computers to communicate over
telephone lines. The transistor gave
way to the concept of parallel processor
and multiprogramming.
Transistor
1961
Grace hopper, the woman that
found the first computer bug,
finishes developing COBOL.
1964
Digital Equipment Corporation
(DEC), founded by Ken Olsen, release
the first minicomputer, the PDP-8.
1965
Thomas Kurtz and John Kemeny
of
Dartmouth College developed
BASIC
(Beginners
All
Purpose
Symbolic Instruction Code) as a
computer language to help teach
people how to program.
The End