Atari 400 Technical Reference Manual page 160

70 NEXT CNT
80 FOR CNT=l TO 4: GOSUB 7000:POSITION 19,CNT+CNT+5:PRINT BUTTONS;
: NEXT CNT
120 GOTO 80
6000 REM ** SET UP FOR CONTROLLERS **
6010 PORTA=54016:PORTB=54017:PACTL=54018:PBCTL=54019
6020 POKE PACTL,48:POKE PORTA, 255: POKE PACTL,52:POKE PORTA. 221
6025 POKE PBCTL, 48:POKEPORTB, 255: POKE PBCTL,52:POKE PORTB,221
6030 ROW(0)=238:ROW{1)=221:ROW{2)=187:ROW(3)=119
6040 IS=II 123456789*0*"
6050 RETURN
7000 REM ** RETURN BUTTONS WITH CHARACTER FOR BUTTON WHICH HAS
BEEN PRESSED ON CONTROLLER CNT (1-4). **
7001 REM ** NOTE: A 1 WILL BE RETURNED IF NO CONTROLLER IS
CONNECTED. **
7002 REM ** A SPACE WILL BE RETURNED IF THE CONTROLLER IS
CONNECTED BUT NO KEY HAS BEEN PRESSED. **
7003 PORT=PORTA: IF CNT>2 THEN PORT=PORTB
7005 P=l
7008 PAO=CNT+CNT-2
7010 FOR
J=O
TO 3
7020 POKE PORT, ROWCJ)
7030 FOR 1=1 TO 10:NEXT I
7050 IF PADDLECPAO+l»10 THEN P=J+J+J+2:GOTO 7090
7060 IF PADDLECPAO»10 THEN P=J+J+J+3:GOTO 7090
7070 IF STRIGCCNT-1)=0 THEN P=J+J+J+4:GOTO 7090
7080 NEXT J
7090 BUTTONS=I$(P,P)
7095 RETURN
Figure 11-4 Reading Data From an ATARI Keyboard Controller
OPERATING SYSTEM C016555 -- Section 11
175