( NMIX-0020 KEYPAD INTERRUPT DRIVEN, PA0

COLD

HEX
 
404 DP !

CODE-SUB CLI
  0E C, ( CLI )
  39 C, ( RTS )
END-CODE

CODE-SUB SEI
  0F C, ( SEI )
  39 C, ( RTS )
END-CODE

( get keypad data from port-e )
: PE@ B00A C@ 2/ 2/ 2/ ;

( display keypad button on terminal )
: HI-LEVEL-IC3 ( INTERRUPT HANDLER FOR IC3 )
    PE@ U.
    01 B023 C! ( CLEAR IC3 FLAG )
;

CODE LO-LEVEL-IC3
CC C, ' HI-LEVEL-IC3 CFA , ( GET ADDRESS OF WORD TO RUN )
BD C, ATO4 ,               ( JSR ATO4 )
3B C,                      ( RTI )
END-CODE

( vector IC3 )
: ENABLE-IC3
    7E B7E3 EEC! ( JMP OP-CODE )
    [ ' LO-LEVEL-IC3 @ >< FF AND ] LITERAL B7E4 EEC! ( HI BYTE STORE )
    [ ' LO-LEVEL-IC3 @    FF AND ] LITERAL B7E5 EEC! ( LO BYTE STORE )
    01 B021 C!  ( CAPTURE ON RISING EDGE )
    01 B022 C!  ( ENABLE IC3 )
;

: MAIN
    ENABLE-IC3
    CLI
    BEGIN
      ." PRESS ANY BUTTON OR TRIGGER PA0 LOW TO GET INTERRUPT "
    ?TERMINAL UNTIL
;