1. COMPUTER FUNDAMENTALS David Samuel Bhatti David.bhatti@seecs.edu.pk

2. Learning Objectives Hexadecimal Octal Number conversion ASCII BCD EBCDIC UNICODE

3. Convert Binary to Hex Group into 4's starting at least significant symbol (if the number of bits is not evenly divisible by 4, then add 0's at the most significant end) write 1 hex digit for each group

4.  Example: Convert 1001 1110 0111 0000 to Hex  After grouping follow the procedure as discussed in the previous section use the symbols of Hex number system like 13=E  1001 1110 0111 0000  9 E 7 0 Convert Binary to Hex

5. Example: Convert 100 1010 011 0000 to Hex 10 0101 0011 0000 0010 0101 0011 0000 2 5 3 0 This group has only two bits, to make it a group of 4 bits add zeros in MSB position

6. Convert Hex to Binary For each of the Hex digit write its binary equivalent (use 4 bits to represent) Example Convert 25A0 to binary 0010 0101 1010 0000

7. Convert Binary To Octal  Group into 3's starting at least significant symbol (if the number of bits is not evenly divisible by 3, then add 0's at the most significant end)  write 1 octal digit for each group

8. Convert Binary To Octal Example: Convert 1001 1110 0111 0000 to Oct After grouping follow the procedure as discussed in the previous section use the symbols of Oct number system like add two zeros here 001 001 111 001 110 000 1 1 7 1 6 0 Answer = 117160 8

9. Convert Octal to Binary For each of the Octal digit write its binary equivalent Example Convert 2570 to binary 010 101 111 000

10. Information Representation All information must be rendered into binary in order to be stored on a computer. Besides numbers, almost all applications must store characters and string information. Images are pervasive in today’s internet world and must be rendered in binary to be handled by internet browsers

11. Character Representation ASCII BCD EBCDIC Unicode

12. ASCII Expanded name American Standard Code for Information Interchange Area covered 7-bit coded character set for information interchange Characteristics/description Specifies coding of space and a set of 94 characters (letters, digits and punctuation or mathematical symbols) suitable for the interchange of basic English language documents. Forms the basis for most computer code sets

13. ASCII

14. BCD  Binary Coded Decimal  In computing and electronic systems, binary-coded decimal (BCD) is a class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of bits, usually four or eight,

15. BCD

16. EBCDIC EBCDIC EBCDIC Expanded name Extended Binary Coded Decimal Interchange Code Expanded name Extended Binary Coded Decimal Interchange Code Proprietary specification developed by IBM Proprietary specification developed by IBM Characteristics/description A set of national character sets for interchange of documents between IBM mainframes. Most EBCDIC character sets do not contain all of the characters defined in the ASCII code Characteristics/description A set of national character sets for interchange of documents between IBM mainframes. Most EBCDIC character sets do not contain all of the characters defined in the ASCII codeASCII

17. EBCDIC EBCDIC EBCDIC Usage Usage Not much used outside of IBM and similar mainframe environments. When transmitting EBCDIC files between systems care needs to be taken to ensure that the systems are set up for the relevant national code set. Not much used outside of IBM and similar mainframe environments. When transmitting EBCDIC files between systems care needs to be taken to ensure that the systems are set up for the relevant national code set.

18. EBCDIC

19. UNICODE  From MSDN: Unicode can represent all of the world's characters in modern computer use, including technical symbols and special characters used in publishing. Because each Unicode code value is 16 bits wide, it is possible to have separate values for up to 65,536 characters. Unicode-enabled functions are often referred to as "wide-character" functions.

20. UNICODE  Note that the implementation of Unicode in 16-bit values is referred to as UTF-16. For compatibility with 8- and 7-bit environments, UTF-8 and UTF-7 are two transformations of 16-bit Unicode values. For more information, see The Unicode Standard, Version 2.0.

21. Key Terms  ASCII  BCD  EBCDIC  UNICODE