Computer Codes

BCD: The binary coded decimal code is based on the idea of converting each digit of a decimal number into its binary equivalent. In 6-bit BCD code the four BCD numeric place positions retained but two additional zone positions are added.

All decimal digits are represented in BCD by 4 bits.

EBCDIC: Extended binary coded decimal inter change code. EBDIC is an -8 bit group it can be easily divided into two 4 bit group. The added 2 bits are used as additional zonal bits expending the zone to 4 bits. is possible to represent 256(28) different characters.

ASCIT:  American standard code for information interchange. It is popular in data communications is used to represent data internally in microcomputers and is frequently found in larger computers. It is of two types.

ASCIT-7: 7Bit code, 128 different characters, first 3 bits zone bits, last 4 bits indicate the digit.

ASCIT-8: 8Bit code, 256 different characters the additional bits added to the zone bits.

Positive verse negative integers floating point number.

TESTING	DEBUTING
It is a process in which a program is validated.	It is process in which program errors are removed.
It is positive activity that seeks to demonstrate that the program is correct.	It is a negative activity in that it is centered on elimination of known error or bugs.
It is complete when all desired verification against specifications has been performed.	Debugging in finished when there are no known error.
Testing can and should be planned it can begin in the early stages of the development effort.	It cannot be planned because it is a reactive procedure which stem from testing.
	It cannot begin until the end of the development cycle because it required an executable program.