Computer
Computers have become the part of everybody's life. Engineers and scientists use computers for difficult/tedious mathematical calculations. The commercial artists use computer as a substitute for his/her canvas. The business executives use the same as a decision-support system. It is used as an input/output system in various organizations like railways, airlines, banks, universities, hospitals and most other service providers. It is also used by children for games and other recreational purposes. Experts are trying to develop systems that will recognize the human voice and ultimate interact with the human beings. Expert systems have already been developed to take decisions like human beings. It is fact difficult to visualize an area where computer has not been used or at least is not likely to be used in the near future. Because of the tremendous impact of computers on the society, it is worthwhile to learn a little about the history development of computers. its functions and the history of the developments computer are discussed in-depth
TYPES OF COMPUTERS
Computers can be classified into three broad categories, namely
() Digital,
(i)
Analog, and
(ii) Hybrid, the details of each category are
given below
Digital Computer
A
Digital Computer deal with digitals data that can be storage into binary format.
Binary data are made of two digits 0 and 1. Such data may be stored in a bit in
the computer's memory. The bit may be in either of two states, namely, "on
state and off stat", which respectively represent the numbers 1 and 0.
Therefore, it is required to convert any type of data (even a graphic image or
a musical note ) into binary format before it is stored in computer memories
Microcomputer
A
Microcomputer is one whose CPU is a microprocessor. The progress in the field
of microcomputers has been phenomenal. From Intel's 8088 chip in 1980's it has
changed to Intel's 80286, 80386, 80486 and Pentium. Microcomputers are used by
engineers, business executives and commercial artists. These are also used in
homes as personal computers. The word size of a microcomputer is 8 to 32
Minicomputer
A Minicomputer possesses greater amount of
memory and storage capacity as compared to microcomputers. The word length of
minicomputer is 32 or more. Minicomputers are usually used as multi-user
systems where a large number of people can work together. The PDP and the VAX
are popular minicomputers
Mainframe Computer
Mainframe Computer is a large and powerful system with a vast amount of memory and storage space. Since the power based tremendously and they are much cheaper, the work that was done earlier by mainframes is being done by PC's. Now-a-day' popular mainframe computers s mainframes work as nodes for large computer networks. The word length of mainframe computers is generally 64. The CDC 6600 and the CYBER 170 are popular mainframe computer
Supercomputer
Supercomputer consists of a number of processors that can process a variety of jobs in parallel. Today's supercomputers one of instructions per second. These are applied mainly for high tech applications like nuclear research, military application, space exploration and similar other applications. The PARAM and the ANURAG are supercomputers manufactured in India and exported to different countries
Analog Computer
Digital
computers convert continuous data into digital signals for processing. This
process of conversion is known as encoding or digitizing. A digital computer
essentially base upon the computer can measure a quantity however an analog
computer can be measure a quantity and process it without the need of any
digitization. Such computers are used mainly in scientific application’s
Hybrid Computer
A
numerically-controlled machine produces cylindrical pins to very close
tolerances. The machine has to keep track of the diameter of pins. This is
possible if the diameter of the product is continuously measured. The instant
diameter of the pin can be sent to the computer as an analog signal. Suppose
the machine has a tool that requires periodic replacement. How can one get a
message when the tool requires replacement This requires analysis of the trend
of the products produced This is essentially statistical analysis of the past
data and best handled as numeric data. One can have a computer to deal with the
measurement of the diameter of the pin through an analog device and analyze the
trend through statistical analysis of numeric data which is digital in nature. A
computer that can deal with the numeric data and analog signals is known as a
hybrid computer".