; ; Ullrich von Bassewitz, 02.06.1998 ; ; int isalpha (int c); ; .export _isalpha .include "ctype.inc" _isalpha: cpx #$00 ; Char range ok? bne @L1 ; Jump if no tay lda __ctype,y ; Get character classification and #CT_ALPHA ; Mask character bits rts @L1: lda #$00 ; Return false tax rts