1. Base 16 (hexadecimal) Uses the decimal digits and the first letters of the alphabet to encode 4 binary bits (16=2 4 ) 0123456789abcdef or 0123456789ABCDEF

2. Base 16 (hexadecimal) Two hex digits encode each 8 bit byte Each 4 bit hex digit is a “nibble” In C and C++, a hexadecimal constant is flagged by an initial '0x' prefix 0x01=1 16 =1 10 0x10=10 16 =16 10 0x24=24 16 =36 10 0xff=0xFF=FF 16 =255 10

3. Base 16 (hexadecimal) Resources: –"man ascii" for ASCII text encoding in hex –"man bc" for conversion between bases –numerous graphical calculations –"man xxd" for dumping files in hex and text

4. Base 16 (hexadecimal) Exercises 1. Use 'bc' to convert 0x34a3f to base 10 2. Write a C program to convert 0x55AF3 to base 8