tailieunhanh - Introduction to Computing (9)

CSC to Computing Lecture 9 Dr. Iftikhar Azim Niaz. ianiaz@. 1Last Lecture Summary .n Number System. n Decimal n Binary n Octal n Hexadecimaln Number conversion. 2 Bits and Binary numbers are made of Bit represents a A byte is 8 Byte represents one character. 3Bit and Byte. 4 Text Converts letters, numbers, special symbols. into binary Standard codes necessary for data Same combinations of numbers to. represent the same individual pieces of Four most popular codes. q EBCDIC. q ASCII. q Extended ASCII. q Unicode 5 Extended Binary Coded Decimal. Interchange 8-bit code to represent 256 Still used in IBM mainframes and mid range. Rarely used in PCs. 6EDCDIC. 7 American Standard Code for Information. Most popular and widely used character Used to represent English 7-bit code to represent 128 characters. q From 0 to 127. q 33 are non-printing control characters (now mostly. obsolete). q 95 printable characters including space (invisible. graphic character) 8ASCII Codes. 9ASCII Code. 10Extended 8-bit code that specifies the characters for. values from 128 to 255n First 40 symbols represent pronunciation and. special punctuation symbol. q 128 to Remaining are for graphics and other. symbols. 11Extended ASCII Code. 12Letter Conversion to Binary. Unicode Worldwide Character Standard. provides up to 4-bytes—32 Can represent more than 4 billion characters. or symbols. q 232 = 1,073,741, Enough for every unique character and. symbol in the world. q Chinese, Korean and Japanese Codes for special mathematical and. scientific First 256 characters are same as ASCII. 14 Binary Similar to arithmetic in decimal number Operations performed. q Addition. q Subtraction. q Multiplication. q Division. 15 Binary i. 16 Binary i. 17 Binary i. 18 Boolean Describes the relationship between the inputs. and outputs of a digital George Boole, an English Mathematician in. 1854 proposed the basic principles of Uses Variables and Boolean variable has only two possible values. q 0 or 1 or False or Basic Logical operations are. q AND, OR and NOT 19 Basic Logical AND operation. q yields true in case when both of its operands are. OR operation. q yields true in case when either or both of its. operands are NOT operation. q Used to invert the value of its operand 20 Logical Truth Table is a list of all possible input values. and the output for each input combination. 21Logical Operations. 22Logical Operations. 23 The Sy