# 5 ascii american standard code for information

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Unformatted text preview: it code, it can be easily divided into two 4-bit groups. Each of these 4-bit groups can be represented by 1 hexadecimal digit. Thus, hexadecimal number system is used as shortcut notation for memory dump by computers that use EBCDIC for internal representation of characters. 5. ASCII (American Standard Code for Information Interchange) is one of the most popular computer codes. It is of two types - ASCII-7 and ASCII-8. ASCII-7 is a 7-bit code, which can represent 128 different characters and ASCII-8 is an 8-bit code, which can represent 256 different characters. Computers, which use ASCII-7 and group of 8 bits for a byte leave the leftmost first bit of each byte as a zero. ASCII also uses hexadecimal as its four-to-one shortcut notation for memory dump. Questions 1. Define the term 'byte'. What is the difference between a bit and a byte? 2. Write the 4-bit BCD code for the following numbers: (a) 25,o (c) 128,0 (b) 64,o (d) 1024,0 3. Using binary notation, show the BCD coding for the following words: (a) BIT (c) CODE (b) BYTE (d) ZERO 4. Using the octal notation, show the BCD coding for the following words: (a) COMPUTER (c) VIDEO (b) INPUT (d) OUTPUT 5. Why was BCD code extended to EBCDIC? 6. How many different characters are possible for the following codes: (a) BCD (c) ASCII-7 (b) EBCDIC (d) ASCII-8 7. Suppose a new computer code is designed that uses 9 bits. How many different characters are possible in this code? 8. Why are octal and hexadecimal shortcut notations used? Identify the shortcut notations used for each of these computer codes: (a) BCD (c) ASCII-7 (b) EBCDIC (d) ASCII-8 9. Why do we have a packed decimal format? How does it differ from a zoned decimal format? 10. Using binary notation, write the EBCDIC coding for the following words: (a) SUN (c) CAT (b) MOON (d) DOG How many bytes are required for each of these representations? 11. Using hexadecimal notation, write the EBCDIC coding for the following words: (a) PROGRAM (c) BYTE (b) OUTPUT (d) OCTAL How many bytes are required for each of these representations? 12. Using hexadecimal notation, write the zoned-decimal coding for the following numbers: (a) 1256 (c) -...
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