Data type and Number system....
binary information in the computer system is stored in memory or processor register. Register can contain data or control information...Control information is a bit used to specify the sequence of command needed for the manipulation of data...Data are the number and other binary coded information that are operated to form a result...The data type found in the register of computer may be classified in the following categories.....(1) number used in arithmetic computations...(2) letter of the alphabet used in data processing...(3) other symbol used for specific purpose....
Number system: In our calculation we use decimal numbers, i.e.0,1,2,3,4,5,6,7,8 & 9 are known as Numbers. The base or radix of a decimal number system is Ten(10).Computers do not processes decimal number system. Computers use binary numbers 0&1.There are some other number systems called Hexadecimal ,octal which are used in assembly language program....
1. Binary: The binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. The usual base-2 system is a positional notation with a radix of 2. It is used in the digital system on which the processor works and operate....
2.Decimal: Decimal, is the base 10 number system, which uses various symbols for ten distinct quantities (0, 1, 2, 3, 4, 5, 6, 7, 8 and 9, called digits) together with the decimal point and the sign symbols + (plus) and − (minus) to represent numbers.
3.octal: The octal numeral system, is the base-8 number system, and uses the digits 0 to 7. In this 421 code is used which is used to convert the octal to binary form .....
4. Hexadecimal: The hexadecimal (also base 16, or hex) is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F
Number system: In our calculation we use decimal numbers, i.e.0,1,2,3,4,5,6,7,8 & 9 are known as Numbers. The base or radix of a decimal number system is Ten(10).Computers do not processes decimal number system. Computers use binary numbers 0&1.There are some other number systems called Hexadecimal ,octal which are used in assembly language program....
1. Binary: The binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. The usual base-2 system is a positional notation with a radix of 2. It is used in the digital system on which the processor works and operate....
2.Decimal: Decimal, is the base 10 number system, which uses various symbols for ten distinct quantities (0, 1, 2, 3, 4, 5, 6, 7, 8 and 9, called digits) together with the decimal point and the sign symbols + (plus) and − (minus) to represent numbers.
3.octal: The octal numeral system, is the base-8 number system, and uses the digits 0 to 7. In this 421 code is used which is used to convert the octal to binary form .....
4. Hexadecimal: The hexadecimal (also base 16, or hex) is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F
EBCDIC ,,BCD,,GREY,,EXCESS 3,,ASCII,,ERROR DET & corr
BCD: Binary-coded decimal (BCD) is an encoding for decimal numbers in which each digit is represented by its own binary sequence. Its main advantage is that it allows easy conversion to decimal digits for display and faster decimal calculations. Its drawbacks is that it occupies more space than a pure binary representation..An extension of BCD code is alphanumeric code. Two extra bits are needed to represent letters and punctuation marks. Seventh bit is added to provide parity bit for error detection. BCD encoding is used for data representation on magnetic tape. ....The table below shows the example of BCD...
EBCDIC: EBCDIC code stands for Extended Binary Coded Decimal Inter Change code. It is also based on the binary coded decimal format. It is an 8 bit code. All the 8 bits are used for representing the information. This code also follows a standard binary progression for coding. This code has totally 256 combinations. In this code, the letter ‘A’ is represented as ‘1100 1000’...Its advantage is It is similar to ASCII code. But in this error correction is not possible...
GREY code: The data in the computer system must be converted before in to digital form before they can be used by it... Continuous the analog and digital signal information is converted into digital form by means of an analog to digital converter...The Gray code is sometime used for the conversion of digital data...The advantage of gray code is that gray code changes by only one bit as its sequence from one number to next..In other words the change of any number to next in sequence is recognize by change of one bit from 0 to 1 or from 1 to 0....
GREY code: The data in the computer system must be converted before in to digital form before they can be used by it... Continuous the analog and digital signal information is converted into digital form by means of an analog to digital converter...The Gray code is sometime used for the conversion of digital data...The advantage of gray code is that gray code changes by only one bit as its sequence from one number to next..In other words the change of any number to next in sequence is recognize by change of one bit from 0 to 1 or from 1 to 0....
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EXCESS 3: The excess 3 is the decimal code that has been using older computer . This is a unweighted code...Its binary code assignment is obtained from the corresponding BCD equivalent binary number after the addition of binary 3(001).....In this the smallest binary number represents the smallest value.(i.e 0 - Excess Value and The greatest binary number represents the largest value...
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ASCII: ASCII stands for the American Standard Code for Information Interchange, As a standard,became widely used . ASCII defines a set of characters which can be displayed by a computer on screen, and some control characters which have special functions. Basic ASCII uses seven bits to define each letter.. The eighth bit was often set aside for error-checking functions, leaving seven remaining for a character set. The main advantage of this code is Error detection can be recognize by increasing the total numbers of bits of 8.
ERROR DET & CORR: An error code is a binary code that detects digital error during transmission. The detected error cannot be corrected but their presence is indicated...The most common error detection codes used is parity bit check...
parity check: The simplest form of error detection is parity; Single parity is established as follows. First, the information is coded in the normal manner using one of the standard binary codes. Each character is then examined to determine whether it contains an even or an odd number of 1 bits...
ERROR DET & CORR: An error code is a binary code that detects digital error during transmission. The detected error cannot be corrected but their presence is indicated...The most common error detection codes used is parity bit check...
parity check: The simplest form of error detection is parity; Single parity is established as follows. First, the information is coded in the normal manner using one of the standard binary codes. Each character is then examined to determine whether it contains an even or an odd number of 1 bits...
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If even parity is to be established, a 1 bit is added to each odd character, and a 0 bit is added to each even character. The result is that all the characters now contain an even number of 1 bits...
error correcting:The weakness of the parity scheme is that we can tell it is having an error, but we can't know which bit is wrong. If we use enough extra bits, we can tell that there is a bit problem but we cannot confirm that which bit is wrong.... Since we need to have enough check bits to spot both an error in the data .. The idea is that we'll divide the data bits into log a subsets where each subset contains half of all the bits, and calculate the even parity of each subset. If w an error occurs, we'll be able to tell which bit has the error because it will be identified by the set of subsets that turn up with bad parity....
error correcting:The weakness of the parity scheme is that we can tell it is having an error, but we can't know which bit is wrong. If we use enough extra bits, we can tell that there is a bit problem but we cannot confirm that which bit is wrong.... Since we need to have enough check bits to spot both an error in the data .. The idea is that we'll divide the data bits into log a subsets where each subset contains half of all the bits, and calculate the even parity of each subset. If w an error occurs, we'll be able to tell which bit has the error because it will be identified by the set of subsets that turn up with bad parity....