10 CJ=0: REM "JOY/ID" SUBROUTINE
20 POKE198,0:POKE56333,17:POKE56320,255
30 C2=(PEEK(56320)AND16)/16:C1=(PEEK(56321)AND16)/16
40 POKE56333,129:IFPEEK(631)=13GOTO80
50 IFC1=0THENCJ=1:GOTO80
60 IFC2=0THENCJ=2:GOTO80
70 GOTO20
80 POKE198,0:RETURN