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CODES OF LANGUAGE IN COMPUTER SYSTEM. WHAT ARE THE OTHER CODES WHICH ARE USED IN COMPUTER SYSTEM?
CODES
OF LANGUAGE IN COMPUTER SYSTEM. WHAT ARE
THE OTHER CODES WHICH ARE USED IN COMPUTER SYSTEM?
There are many codes in computer system which may remain unnoticed by many computer geeks and nerds. I also first didn’t see it but I am going to share it because these are important codes and used by many computer hardware developers, vendors and computer software developers. They are mostly understood by ELECTRONICS AND ELECTRICAL ENGINEERING geeks or nerds. They are as under :
· ERROR DETECTION CODES
·
ALPHANUMERIC
CODES
· REFTLECTED CODES
First we will discuss something about ERROR DETECTION CODES.
ERROR DETECTION CODES:
Binary information , be it pulse modulated
signals or digital computer input or output, may be transmitted though some
form of communication medium or electrical wires or radio waves. Any external noise introduced into physical
communication medium or electric wires changes bit values from 0 to 1 or vice
versa. An error detection code can be
used to detect errors during transmission.
The detected error cannot be corrected but its presence is
indicated. The usual procedure is to
observe the frequency of errors. If errors
occur only once a while, at random and without a pronounced effect on the
overall information transmitted then either nothing is done or particular erroneous
message is transmitted again. If errors
occur so often to distort the meaning of the received information, the system
is checked for malfunction. A parity bit
is added at the end of the message to make the message to become odd if it is
even or make it even if it is odd. I am
talking about the binary numbers generated by the software from the message
that is passed , during transfer of
information from one location to another, the parity bit is handled as
follows. In the sending end, the message
(in this case the first four bits) is applied in “parity generation” where the
parity bit is generated. The message as
well as the parity bit is transferred to its destination. In the receiving end the message which is
converted to binary numbers are taken with along with the parity bit into the
parity bit network to check the parity bit.
An error is generated if the parity bit is not the same as generated or
let’s says an error is detected if the checked parity does not correspond to
the adopted one. The parity method
detect the presence of one, three, or any old combination of errors. An
even combination of errors is undetectable.
ALPHANUMERIC CODES:
Many applications of digital computers
required the handling of data that consist not only of numbers, but also of
letters. For instance, an insurance
company with millions of policy holders may use a digital computer to process
its files. To represent any policy
holders may use a digital computer to process its files. To represent the policy holders name in
binary form, it is necessary to have
binary code for that alphabet. In
addition, the same binary code must represent decimal numbers and some other
special characters. An alphanumeric
(sometimes abbreviated alphanumeric) code is a binary code of a group of
elements consisting of ten decimal digits, the 26 letters of the alphabet and a
certain number of special symbols such as $.
The total number of elements in an alphanumeric group is greater than
36. Therefore, it must be coded with a
minimum of six bits (26 = 64, but 25 = 32 is
insufficient). One possible arrangement
of a six bit alphanumeric code is also called internal code. The need to represent more than 64 characters
(the lowercase letters and special control characters for the transmission of
digital information) gave rise to seven- and eight-bit alphanumeric codes. One such code is known as ASCII( American
Standard Code For Information Interchange);
another is known as EBCDIC(Extended Binary Code Decimal Interchange
Code). Let us discuss something about
ASCII codes : In ASCII code listed in various books consists of seven bits, but is for all practical purposes an eight
bit code , because an eight bit is used as parity. When discrete information is transferred
through a punch card, the alphanumeric characters is used 12bit binary
code. A punch card contains 80 columns
and 12 rows. The 12 rows are marked
starting from the 12 the row and preceding backwards such as 12, 11, 10, 9, 8
and so on punches. The first three are
called zone punch and last nine are called numeric punch. The 12 bit card code can be seen through
internet searches.
REFLECTED CODE:
Digital systems can be designed to process
data in discrete form only. Many
physical systems supply continuous output data.
These data must be converted into digital or discrete form they are
applied to a digital system. Continuous
or analog information is converted into digital form by means of analog to
digital converter. It is sometimes
convenient to use the reflected code to represent digital data converted from analog data. The advantage of the reflected code over pure
binary numbers is that a number in the reflected code changes by only one bit
as it proceeds from one number to the next.
A typical application of the reflected code occurs when the reflected
code occurs when the analog data are
represented by a continuous change of a shaft position. The shaft is partitioned into a segments, and
each segment is assigned a number. If
theadjacent segments are made to correspond to adjacent reflected code numbers,
ambiguity is reduced when detection is sensed in the line that separates any
two segments.
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