LOWER CASE starts with 011 & UPPER CASE starts with 010 and then the five numbers are the same for both upper and lower case.

Aa = 00001

Bb = 00010

Cc = 00011

Dd = 00100

Ee = 00101

Ff = 00110

Gg = 00111

Hh = 01000

Ii = 01001

Jj = 01010

Kk = 01011

Ll = 01100

Mm = 01101

Nn = 01110

Oo = 01111

Pp = 10000

Qq = 10001

Rr = 10010

Ss = 10011

Tt = 10100

Uu = 10101

Vv = 10110

Ww = 10111

Xx = 11000

Yy = 11001

Zz = 11010