square root of positive numbers, no sign bit
p= 00010000, u= 0100
p= 00000000, u= 0000
p= 11111111, u= 1111
p= 11100001, u= 1111
p= 11110000, u= 1111
p= 10000000, u= 1011
p= 10010000, u= 1100
p= 11000000, u= 1101
p= 00000001, u= 0001
p= 00000010, u= 0001
p= 00000011, u= 0001
p= 00000100, u= 0010
p= 00001111, u= 0011
p= 01000000, u= 1000
sqrt.run finished