Commodore Amiga A500 - Page 134

READ SHlFT STATUS (AH = 02H)
INPUT: DS = ROM data segment (0040h)
OUTPUT: AL = SHlFT STATUS BYTE
CASSEITE INT 1 SH DSR
OUTPUT: AH = 86h, Error code, Carry set.
Interrupts off
KYBDSR ENTRY POINT
READ KEYBOARD INPUT (AH = OOH)
VIA S/W INT 16H
INPUT: DS = ROM data segment (0040h)
OUTPUT: AL = ASCll CHARACTER
AH =SCAN CODE
READ KEYBOARD STATUS (AH = 01 H)
INPUT: DS
= ROM data segment (0040h)
OUTPUT: AL = ASCll CHARACTER
AH =SCAN CODE
Z FLAG = 1 if no character available
Z FLAG = 0 if character available
READ SHlFT STATUS (AH = 02H)
INPUT: DS
= ROM data segment (0040h)
OUTPUT: AL = SHlFT STATUS BYTE
PRINTER ENTRY POINT
PRINT CHARACTER (AH = OOH)
VIA S/W INT 17H
INPUT: AL = Character to output
DX = Index to Printer kble port + 1
(the Status port)
CX = Timeout value
OUTPUT: AH
= Printer Status