Computers in some form are in almost everything these days. From Toasters to
Televisions, just about all electronic things has some form of processor in them. This
is a very large change from the way it used to be, when a computer that would take up an
entire room and weighed tons of pounds has the same amount of power as a scientific
calculator. The changes that computers have undergone in the last 40 years have been
colossal. So many things have changed from the ENIAC that had very little power, and
broke down once every 15 minutes and took another 15 minutes to repair, to our Pentium
Pro 200's, and the powerful Silicon Graphics Workstations, the core of the machine has
stayed basically the same. The only thing that has really changed in the processor is
the speed that it translates commands from 1's and 0's to data that actually means
something to a normal computer user. Just in the last few years, computers have
undergone major changes. PC users came from using MS-DOS and Windows 3.1, to Windows 95,
a whole new operating system. Computer speeds have taken a huge increase as well, in
1995 when a normal computer was a 486 computer running at 33 MHz, to 1997 where a
blazing fast Pentium (AKA 586) running at 200 MHz plus. The next generation of
processors is slated to come out this year as well, being the next CPU from Intel, code
named Merced, running at 233 MHz, and up. Another major innovation has been the
Internet. This is a massive change to not only the computer world, but to the entire
world as well. The Internet has many different facets, ranging from newsgroups, where
you can choose almost any topic to discuss with a range of many other people, from
university professors, to professionals of the field of your choice, to the average
person, to IRC, where you can chat in real time to other people around the world, to the
World Wide Web, which is a mass of information networked from places around the world.
Nowadays, no matter where you look, computers are somewhere, doing something.
Changes in computer hardware and software have taken great leaps and jumps since the
first video games and word processors. Video games started out with a game called
Pong...monochrome (2 colors, typically amber and black, or green and black), you had 2
controller paddles, and the game resembled a slow version of Air Hockey. The first word
processors had their roots in MS-DOS, these were not very sophisticated nor much better
than a good typewriter at the time. About the only benefits were the editing tools
available with the word processors. But, since these first two dinosaurs of software,
they have gone through some major changes. Video games are now placed in fully 3-D
environments and word processors now have the abilities to change grammar and check your
spelling.
Hardware has also undergone some fairly major changes. When computers entered their 4th
generation, with the 8088 processor, it was just a base computer, with a massive
processor, with little power, running at 3-4 MHz, and there was no sound to speak of,
other than blips and bleeps from an internal speaker. Graphics cards were limited to two
colors (monochrome), and RAM was limited to 640k and less. By this time, though,
computers had already undergone massive changes. The first computers were massive beasts
of things that weighed thousands of pounds. The first computer was known as the ENIAC,
it was the size of a room, used punched cards as input and didn't have much more power
than a calculator. The reason for it being so large is that it used vacuum tubes to
process data. It also broke down very often...to the tune of once every fifteen minutes,
and then it would take 15 minutes to locate the problem and fix it. This beast also used
massive amount of power, and people used to joke that the lights would dim in the city of
origin whenever the computer was used.
The Early Days of Computers
The very first computer, in the roughest sense of the term, was the abacus. Consisting
of beads strung on wires, the abacus was the very first desktop calculator. The first
actual mechanical computer came from an individual named Blaise Pascal, who built an
adding machine based on gears and wheels. This invention did not become improved
significantly until a person named Charles Babbage came along, who made a machine called
the difference engine. It is for this, that Babbage is known as the "Father of the
Computer."
Born in England in 1791, Babbage was a mathematician, and an inventor. He decided a
machine could be built to solve polynomial equations more easily and accurately by
calculating the differences between them. The model of this was named the Difference
Engine. The model was so well received that he began to build a full scale working
version, with money that he received from the British Government as a grant.
Babbage soon found that the tightest design specifications could not produce an accurate
machine. The smallest imperfection was enough to throw the tons of mechanical rods and
gears, and threw the entire machine out of whack. After spending 17,000 pounds, the
British Government withdrew financial support. Even though this was a major setback,
Babbage was not discouraged. He came up with another machine of wheels and cogs, which
he would call the analytical engine, which he hoped would carry out many different kinds
of calculations. This was also never built, at least by Babbage (although a model was
put together by his son, later), but the main thing about this was it manifested five key
concepts of modern computers --
? Input device
? Processor or Number calculator
? Storage unit to hold number waiting to be processed
? Control unit to direct the task waiting to be performed and the sequence of
calculations
? Output device
Parts of Babbage's inventions were similar to an invention built by Joseph Jacquard.
Jacquard, noting the repeating task of weavers working on looms, came up with a stiff
card with a series of holes in it, to block certain threads from entering the loom and
blocked others from completing the weave. Babbage saw that the punched card system could
be used to control the calculations of the analytical engine, and brought it into his
machine.
Ada Lovelace was known as the first computer programmer. Daughter of an English poet
(Lord Byron), went to work with Babbage and helped develop instructions for doing
calculations on the analytical engine. Lovelace's contributions were very great, her
interest gave Babbage encouragement; she was able to see that his approach was workable
and also published a series of notes that led others to complete what he prognosticated.
Since 1970, the US Congress required that a census of the population be taken every ten
years. For the census for 1880, counting the census took 7? years because all counting
had to be done by hand. Also, there was considerable apprehension in official society as
to whether the counting of the next census could be completed before the next century.
A competition was held to find some way to speed the counting process. In the final
test, involving a count of the population of St. Louis, Herman Hollerith's tabulating
machine completed the count in only 5? hours. As a result of his systems adoption, an
unofficial count of the 1890 population was announced only six weeks after the census was
taken. Like the cards that Jacquard used for the loom, Hollerith's punched cards also
used stiff paper with holes punched at certain points. In his tabulating machine, roods
passed through the holes to complete a circuit, which caused a counter to advance one
unit. This capability pointed up the principal difference between the analytical engine
and the tabulating machine; Hollerith was able to use electrical power rather than
mechanical power to drive the device.
Hollerith, who had been a statistician with the Census Bureau, realized that the punched
card processing had high potential for sales. In 1896, he started the Tabulating Machine
Company, which was very successful in selling machines to railroads and other clients.
In 124, this company merged with two other companies to form the International Business
Machines Corporation, still well known today as IBM.
IBM, Aiken & Watson
For over 30 years, from 1924 to 1956, Thomas Watson, Sr., ruled IBM with an iron grip.
Before becoming the head of IBM, Watson had worked for the Tabulating Machine Company.
While there, he had a running battle with Hollerith, whose business talent did not match
his technical abilities. Under the lead of Watson, IBM became a force to be reckoned
with in the business machine market, first as a purveyor of calculators, then as a
developer of computers.
IBM's entry into computers was started by a young person named Howard Aiken. In 1936,
after reading Babbage's and Lovelace's notes, Aiken thought that a modern analytical
engine could be built. The important difference was that this new development of the
analytical engine would be electromechanical. Because IBM was such a power in the
market, with lots of money and resources, Aiken worked out a proposal and approached
Thomas Watson. Watson approved the deal and give him 1 million dollars in which to make
this new machine, which would later be called the Harvard Mark I, which began the modern
era of computers.
Nothing close to the Mark I had ever been built previously. It was 55 feet long and 8
feet high, and when it processed information, it made a clicking sound, equivalent to
(according to one person) a room full of individuals knitting with metal needles.
Released in 1944, the sight of the Mark I was marked by the presence of many uniformed
Navy officers. It was now W.W.II and Aiken had become a naval lieutenant, released to
Harvard to help build the computer that was supposed to solve the Navy's obstacles.
During the war, German scientists made impressive advances in computer design. In 1940
they even made a formal development proposal to Hitler, who rejected farther work on the
scheme, thinking the war was already won. In Britain however, scientists succeeded in
making a computer called Colossus, which helped in cracking supposedly unbreakable German
radio codes. The Nazis unsuspectingly continued to use these codes throughout the war.
As great as this accomplishment is, imagine the possibilities if the reverse had come
true, and the Nazis had the computer technology and the British did not.
In the same time frame, American military officers approached Dr. Mauchly at the
University of Pennsylvania and asked him to develop a machine that would quickly
calculate the trajectories for artillery and missiles. Mauchly and his student, Presper
Eckert, relied on the work of Dr. John Atanasoff, a professor of physics at Iowa State
University.
During the late '30's, Atanasoff had spent time trying to build an electronic
calculating device to help his students solve complicated math problems. One night, the
idea came to him for linking the computer memory and the associated logic. Later, he and
an associate, Clifford Berry, succeeded in building the "ABC," for Atanasoff-Berry
Computer. After Mauchly met with Atanasoff and Berry, he used the ABC as the basis for
the next computer development. From this association ultimately would come a lawsuit,
considering attempts to get patents for a commercial version of the machine that Mauchly
built. The suit was finally decided in 1974, when it was decided that Atanasoff had been
the true developer of the ideas required to make an electronic digital computer actually
work, although some computer historians dispute this decision. But during the war years,
Mauchly and Eckert were able to use the ABC principals in dramatic effect to create the
ENIAC.
Computers Become More Powerful
The size of ENIAC's 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 about 1000 times faster than the
previous generation of 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
input, 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. The problem with
the ENIAC was that the average life of a vacuum tube is 3000 hours, and a vacuum tube
would then burn out once every 15 minutes. It would take on average 15 minutes to find
the burnt out tube and replace it.
Enthralled by the success of ENIAC, the mathematician John Von Neumann undertook, in
1945, a study of computation that showed that a computer should have a very basic, fixed
physical construction, and yet be able to carry out any kind of computation by means of a
proper programmed control without the need for any change in the unit itself. Von Neumann
contributed a new consciousness of how sensible, yet fast computers should be organized
and assembled. These ideas, usually referred to as the stored-program technique, became
important for future generations of high-speed digital computers and were wholly adopted.
The Stored-Program technique involves many features of computer design and function
besides the one that it is named after. In combination, these features make very high
speed operations attainable. An impression may be provided by considering what 1,000
operations per second means. If each instruction in a job program were used once in
concurrent order, no human programmer could induce enough instruction to keep the
computer busy. Arrangements must be made, consequently, for parts of the job program
(called subroutines) to be used repeatedly in a manner that depends on the way the
computation goes. Also, it would clearly be helpful if instructions could be changed if
needed during a computation to make them behave differently. Von Neumann met these two
requirements by making a special type of machine instruction, called a Conditional
control transfer -- which allowed the program sequence to be stopped and started again at
any point - and by storing all instruction programs together with data in the same memory
unit, so that, when needed, instructions could be changed in the same way as data.
As a result of these techniques, computing and programming became much faster, more
flexible, and more efficient with work. Regularly used subroutines did not have to be
reprogrammed for each new program, but could be kept in "libraries" and read into memory
only when needed. Hence, much of a given program could be created from the subroutine
library. The computer memory became the collection site in which all parts of a long
computation were kept, worked on piece by piece, and put together to form the final
results. When the advantage of these techniques became clear, they became a standard
practice.
The first generation of modern programmed electronic computers to take advantage of these
improvements was built in 1947. This group included computers using Random-
Access-Memory (RAM), which is a memory designed to give almost constant access to any
particular piece of information. . These machines had punched-card or tape I/O devices.
Physically, they were much smaller than ENIAC. Some were about the size of a grand piano
and used only 2,500 electron tubes, a lot less then required by the earlier ENIAC. The
first-generation stored-program computers needed a lot of maintenance, reached probably
about 70 to 80% reliability of operation (ROO) and were used for 8 to 12 years. This
group of computers included EDVAC and UNIVAC, the first commercially available computers.
Early in the 50's 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 1960's, 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
potential available. During this time, another important development was the move from
machine language to assembly language, also known as symbolic languages. Assembly
languages use abbreviations for instructions rather than numbers. This made programming
a computer a lot easier.
After the implementation of assembly languages came high-level languages. The first
language to be universally accepted was a language by the name of FORTRAN, developed in
the mid 50's as an engineering, mathematical, and scientific language. Then, in 1959,
COBOL was developed for business programming usage. Both languages, still being used
today, are more English like than assembly. Higher level languages allow programmers to
give more attention to solving problems rather than coping with the minute details of the
machines themselves. Disk storage complimented magnetic tape systems and enabled users
to have rapid access to data required.
All these new developments made the second generation computers easier and less costly
to operate. This began a surge of growth in computer systems, although computers were
being mostly used by business, university, and government establishments. They had not
yet been passed down to the general public. The real part of the computer revolution was
about to begin.
One of the most abundant elements in the earth is silicon; a non-metal substance found
in sand as well as in most rocks and clay. The element has given rise to the name
"Silicon Valley" for Santa Clara County, about 50 km south of San Francisco. In 1965,
Silicon valley became the principle site of the computer industry, making the so-called
silicon chip.
An integrated circuit is a complete electronic circuit on a small chip of silicon. The
chip may be less than 3mm square and contain hundreds to thousands of electronic
components. Beginning in 1965, the integrated circuit began to replace the transistor in
machines was now called third-generation computers. An Integrated Circuit was able to
replace an entire circuit board of transistors with one chip of silicon much smaller
than one transistor. Silicon is used because it is a semiconductor. It is a crystalline
substance that will conduct electric current when it has been doped with chemical
impurities shot onto the structure of the crystal. A cylinder of silicon is sliced into
wafers, each about 76mm in diameter. The wafer is then etched repeatedly with a pattern
of electrical circuitry. Up to ten layers may be etched onto a single wafer. The wafer
is then divided into several hundred chips, each with a circuit so small it is half the
size of a fingernail; yet under a microscope, it is complex as a railroad yard. A chip 1
centimeter square it is so powerful that it can hold 10,000 words, about the size of an
average newspaper.
Integrated circuits entered the market with the simultaneous announcement in 1959 by
Texas Instruments and Fairchild Semiconductor that they had each independently produced
chips containing several complete electronic circuits. The chips were hailed as a
generational breakthrough because they had four desirable characteristics.
? Reliability - They could be used over and over again without failure, whereas vacuum
tubes failed ever fifteen minutes. Chips rarely failed -- perhaps one in 33 million
hours of operation. This reliability was due not only to the fact that they had no
moving parts but also that semiconductor firms gave them a rigid work/not work test.
? Compactness - Circuitry packed into a small space reduces equipment size. The machine
speed is increased because circuits are closer together, thereby reducing the travel
time for the electricity.
? Low Cost - Mass-production techniques has made possible the manufacture of inexpensive
integrated circuits. That is, miniaturization has allowed manufacturers to produce many
chips inexpensively.
? Low power use -- Miniaturization of integrated circuits has meant that less power is
required for computer use than was required in previous generations. In an
energy-conscious time, this was important.
The Microprocessor
Throught the 1970's, computers gained dramatically in speed, reliability, and storage
capacity, but entry into the fourth generation was evolutionary rather than
revolutionary. The fourth generation was, in fact, furthering the progress of the third
generation. Early in the first part of the third generation, specialized chips were
developed for memory and logic. Therefore, all parts were in place for the next
technological development, the microprocessor, or a general purpose processor on a chip.
Ted Hoff of Intel developed the chip in 1969, and the microprocessor became commercially
available in 1971.
Nowadays microprocessors are everywhere. From watches, calculatores and computers,
processors can be found in virtually every machine in the home or business. Environments
for computers have changed, with no more need for climate-controlled rooms and most
models of microcomputers can be placed almost anywhere.
New Stuff
After the technoligical improvements in the 60's and the 70's, computers haven't gotten
much different, aside from being faster, smaller and more user friendly. The base
architecture of the computer itself is fundementally the same. New improvements from the
80's on have been more "Comfort Stuff", those being sound cards (For hi-quality sound and
music), CD-ROMs (large storage capicity disks), bigger monitors and faster video cards.
Computers have come a long way, but there has not really been alot of vast technological
improvements, architecture-wise.
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