GN_Cls, Classify character
Register parameters
RST 20H, DEFW $3009
IN: A = character to classify OUT: F = flags indicate classification, as follows: Fc = 0, Fz = 0: Neither alphabetic or numeric Fc = 0, Fz = 1: Numeric ('0' ... '9') Fc = 1, Fz = 0: Upper case letter ('A' ... 'Z') Fc = 1, Fz = 1: Lower case letter ('a' ... 'z') Registers changed after return: A.BCDEHL/IXIY same .F....../.... different