Information Technology - Basic computer architecture
Basic computer architecture
Basic computer architecture.
Throughout their short history computers have decreased from being room
size to only a little larger than A4 paper size.
Computer schematics represent the individual components of a computer.
are the oldest computers and are very large - mainframes formed the
backbone of most computer systems until the early 1980's, and it was not
uncommon for these machines to take up entire rooms. A mainframe computer
was a powerful computer for its time, however, they were superseded in
large organisations by the
The supercomputers are more powerful than mainframes and are primarily
used by government departments and large organisations, (although as the
design of circuits has advanced, computers have become much smaller than
the less powerful mainframes).
In the 1970s a trend to smaller computers emerged. These computers were
called or These computers were significantly smaller than the earlier
mainframes, but once again, due to advances in design, they were often more
This computer evolved into an even smaller computer called the The
microcomputer is what we have come to recognise as the desktop computers
that we use today. These computers are more powerful than the mainframes
that were used in the 1960s - but take up a fraction of the space.
Today's computers are more powerful because of the advent of the silicon
integrated circuit chip or as it is more commonly known, the silicon chip.
The silicon chip allows large amounts of circuitry, which previously had to
be physically constructed, to be etched onto a chip that needs to be no
bigger than a fingernail. The silicon chip is the basis for the
microprocessor - the centre of the modern computer.
The microcomputer is often referred to as a or a Strictly speaking, a
small business computer is defined as a multi user computer system in an
organisation and a personal computer is a micro computer that is used by a
single person - however today, the term personal computer is a generic term
that is used to refer to any microcomputer. Note - this definition regards
all micros as "PC" and not just those that conform to the platform.
Although the computers that we use today have very little in common with
the computers that were used in the early information systems, all
computers still conform to a basic architecture, represented by the diagram
The most important unit in a computer is the central processing unit
(CPU). It controls all of the separate components of the computer and
transforms the input to output. The CPU has three major components - the
the and the and The primary storage unit is often referred to as the
main memory, it contains both the data being processed and the list of
instructions to process the data (the The arithmetic and logic unit is
where the calculations and logical operations take place. The control unit,
as the name implies, is the unit that ensures that all of the components
work as a system, or controls it. The ALU and control unit are often
referred to as a single unit and called the processor.
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