A Brief History of the Computer
Computers and computer applications are on almost every aspect of our daily
lives. As like many ordinary objects around us, we may need clearer understanding
of what they are. You may ask "What is a computer?" or "What
is a software", or "What is a programming language?" First, let's
examine the history.
- The history of computers starts out about 2000 years ago in Babylonia (Mesopotamia), at the birth of
the abacus, a wooden
rack holding two horizontal wires with beads strung on them.
l is usually credited for building the first digital
in 1642. It added numbers entered with dials and was made to
help his father, a tax collector.
The basic principle
of his calculator is still used today in water meters and modern-day odometers.
Instead of having a carriage wheel turn the gear, he made each ten-teeth
wheel accessible to be turned directly by a person's hand (later inventors
added keys and a crank), with the result that when the wheels were turned
in the proper sequences, a series of numbers was entered and a cumulative
sum was obtained. The gear train supplied a mechanical answer equal to the
answer that is obtained by using arithmetic.
This first mechanical calculator, called the Pascaline, had several disadvantages.
Although it did offer a substantial improvement over manual calculations,
only Pascal himself could repair the device and it cost more than the people
it replaced! In addition, the first signs of technophobia emerged with mathematicians
fearing the loss of their jobs due to progress.
- A step towards automated computing was the development of punched
cards, which were first successfully used with computers in 1890 by Herman
Hollerith and James Powers, who worked for the US.
Census Bureau. They developed devices that could read the information
that had been punched into the cards automatically, without human help. Because
of this, reading errors were reduced dramatically, work flow increased, and,
most importantly, stacks of punched cards could be used as easily accessible
memory of almost unlimited size. Furthermore, different problems could be
stored on different stacks of cards and accessed when needed.
- These advantages were seen by commercial companies and soon led to the development
of improved punch-card using computers created by International Business Machines (IBM), Remington (yes, the same people that make shavers), Burroughs, and
other corporations. These computers used electromechanical devices in which
electrical power provided mechanical motion -- like turning the wheels of
an adding machine. Such systems included features to:
- feed in a specified number of cards automatically
- add, multiply, and sort
- feed out cards with punched results
- The start of World War II produced a large need for computer capacity, especially
for the military. New weapons were made for which trajectory tables and other
essential data were needed. In 1942, John P. Eckert, John
W. Mauchly, and their associates at the Moore school of Electrical Engineering
of University of Pennsylvania decided to build a high - speed electronic computer
to do the job. This machine became known as ENIAC
(Electrical Numerical Integrator And Calculator)
The size of ENIACís numerical "word" was 10 decimal digits, and it could multiply
two of these numbers at a rate of 300 per second, by finding the value of
each product from a multiplication table stored in its memory. ENIAC was therefore
about 1,000 times faster then the previous generation of relay computers.
ENIAC used 18,000 vacuum tubes, about 1,800 square feet of
floor space, and consumed about 180,000 watts of electrical power. It had
punched card I/O, 1 multiplier, 1 divider/square rooter, and 20 adders using
decimal ring counters, which served as adders and also as quick-access (.0002
seconds) read-write register storage. The executable instructions making up
a program were embodied in the separate "units" of ENIAC, which were plugged
together to form a "route" for the flow of information.
||Two men (in uniform) being trained to maintain the ENIAC
computer. The two women in the photo were programmers. The ENIAC occupied
the entire thirty by fifty feet room.
- Early in the 50ís two important engineering discoveries changed the image
of the electronic - computer field, from one of fast but unreliable hardware
to an image of relatively high reliability and even more capability. These
discoveries were the magnetic
core memory and the Transistor
- Circuit Element.
These technical discoveries quickly found their way into new models of digital
computers. RAM capacities increased from 8,000 to 64,000 words in commercially
available machines by the 1960ís, with access times of 2 to 3 MS (Milliseconds).
These machines were very expensive to purchase or even to rent and were particularly
expensive to operate because of the cost of expanding programming. Such computers
were mostly found in large computer centers operated by industry, government,
and private laboratories - staffed with many programmers and support personnel.
This situation led to modes of operation enabling the sharing of the high
- Many companies, such as Apple Computer and Radio Shack, introduced very
successful PCís in the 1970's, encouraged in part by a fad in computer (video)
games. In the 1980's some friction occurred in the crowded PC field, with
Apple and IBM keeping strong. In the manufacturing of semiconductor chips,
the Intel and Motorola Corporations were very competitive into the 1980s,
although Japanese firms were making strong economic advances, especially in
the area of memory chips. By the late 1980s, some personal computers were
run by microprocessors that, handling 32 bits of data at a time, could process
about 4,000,000 instructions per second.
This page is compiled with contents from "A Short History of the Computer"
by Meyers, Jeremy. It's vailable at http://www.softlord.com/comp