DE_MF

Excess-3 code DECIMAL 0 1 2 3 4 5 6 7 8 9

EXCESS-3 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 31

ALPHANUMERIC C These codes contain not only Hence the name. For communication between 2 a binary based code which c alphabets as well as the num this have 7 to 8 bits /word and codes. There are several types of alph the ASCII and EBCDIC.

CODE y numerical but also alphabets. or more computers, one needs can represent the letters of thembers. Common codes used for are referred to as alphanumerichanumeric codes two of them are 32

ASCII The American Standard Code for a character-encoding scheme alphabet. ASCII codes represent text equipment, and other devices tha Most modern character-encodin though they support many more c

r Information Interchange (ASCII) is originally based on the English in computers, communicationsat use text.ng schemes are based on ASCII,characters than ASCII does. 33

ASCIILetter ASCII Code Binary a 097 01100001 b 098 01100010 c 099 01100011 d 100 01100100 e 101 01100101 f 102 01100110 g 103 01100111 h 104 01101000 i 105 01101001

Letter ASCII Code Binary A 065 01000001 B C 066 01000010 D E 067 01000011 F 068 01000100 G 069 01000101 H 070 01000110 I 071 01000111 072 01001000 073 01001001 34

EBCDIC CODE EBCDIC which stands for Decimal Interchange Code used on IBM mainframe EBCDIC takes up eight bi pieces. The first four bits are called category of the character, w the called the digit and iden

the Extended Binary Coded is an 8 bit character encodinges and AS/400s.Single byte its, which are divided in two d the zone and represent the whereas the last four bits arentify the specific character. 35

2.5 Perform Arithmetic op all basic number sys  Remember: −2n−1 ≤ Two's C −8 ≤ x[4 −128 ≤ x[8 −32768 ≤ x[1 −2147483648 ≤ x[3

perations on stemsComplement ≤ 2n−1 − 1 4] ≤ +7 8] ≤ +12716] ≤ +3276732] ≤ +2147483647 36

Binary Addition (1 o• Two 1-bit values AB 00 01 10 11

of 2) A+B 0 1 1 10 “two” 37

Binary Addition (2• Two n-bit values – Add individual bits – Propagate carries – E.g., 11 10101 + 11001 101110

2 of 2) 21+ 25 46 38

Two's Complement Subtraction Normally accomplished by nega it to the minuhend. Any carry-ou Example: Using 8-bit Two's Co+127)(+8) 0000 1000 00−(+5) 0000 0101 -> Negate -> +11-------- ----(+3) 1 00

ating the subtrahend and addingut is discarded.omplement Numbers (−128 ≤ x ≤000 1000111 1011 ------------- 000 0011 : discard carry-out 39