DATA REPRESENTATION

BCD meaning

• a method of using binary digits to represent decimal digits 0-9.

• Eg 19 to 0011001

• BCD are represented using 4bits

BCD addition

• Whenever the sum of 2 BCD digits are greater than 9, 6 has to be added to give the actual result, inorder to skip the unused codes (addition is done in binary form)

EBCDIC meaning

Extended binary coded decimal interchange code

Describe the EBCDIC

• Uses 8bit code, hence 256 xters can be represented(letters, n#,symbols)

• Most used today especially, by larger computers(mainframe)

ASCII

American standard code for Information Interchange

Describtion of ASCII

• A 7 bit code( representx 2^7 xters)

• Used in macro and mini computers

ASCII-7 code representation

• CCodes 0 to 31: control xters(non printable)

• Codes 48 to 57: numeric 0 to

• 65 to 90: A to Z

• 97 to 122: a to z

• 128 to 255: Extended Ascii codes

UNICODE

• 32 bit code (represents 2³² xters)

• Mathematical and scientific symbols are included

• Compatible with ASCII-8 codes

Advan of UNICODE

• More xters represented

• Many languages represented

• Can encode many smbols

• Uses more bytes for larger alphabetic symbols, ( need more space)