Binary Numbers and Bit Patterns author Neil Franklin, last modification 2004.01.01 on example of 4bit counter f b u s c u i n i o n n s g u c a i n n t r g e t n y n d C 0000 (0) B 1111 15 1110 14 1101 13 1100 12 1011 11 1010 10 1001 9 O 1000 8 (-8) U 0111 7 7 0110 6 6 0101 5 5 0100 4 4 ^ = +1 0011 3 3 v = -1 0010 2 2 0001 1 1 C 0000 0 0 B 1111 (15) -1 1110 -2 1101 -3 1100 -4 1011 -5 1010 -6 1001 -7 O 1000 -8 U 0111 (7) ^- C = carry, B = borrow, O = overflow, U = underflow