30 IF PEEK(&4000)=&C7 THEN PRINT"PAL chip absent/inactive":END
40 OUT &3FFF,&C7
50 IF PEEK(&4000)=&C7 THEN PRINT"PAL I/O layout Bit 14=0 PAL Select":ENDGOTO 8060 IF PEEK(&4000)=&C0 THEN PRINT"PAL I/O layout Bit 14=0 PAL not selected":ENDGOTO 80
70 PRINT"Error!"
80 OUT &7F00,&C0:POKE &C000,&C3:OUT &7F00,&C3
90 IF PEEK(&4000)=&C3 THEN PRINT"Valid RAM mode &C3" ELSE PRINT"Invalid RAM mode &C3"
</pre>