Commodore Amiga A500 - Page 133

RETURN SERIAL PORT STATUS (AH = 03H)
INPUT: DX
= Modem Control Register port
OUTPUT: AH
= Line Status
AL
= Modem Status
Serial Port Status bits returned in
AX Register:
AH Reg~ater:
b1tl7l6l5l4l3l2l1lOl
> Data Ready
> Overrun Error
> Parity Error
> Framing Error
> Break Error
> Transmit hold register empty
> Transmit shift register empty
> Timeout Error
AH Register:
bitl7l61514l3l2lIlOl
> Delta Clear To Send
> Delta Data Set Ready
> Trail~ng edge Ring Detect
> Delta Receive Line Signal detect
> Clear To Send
> Data Set Ready
> Ring Indicator
I
> ~eceive Line Signal Detect
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 = 0 1 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