10 SCREEN 2:PUT SPRITE 0,(0,&HD0),0,0
11 A=&HAA:FOR I=0 TO &H17FF:POKE&H8800+I,A:A=A XOR 255:NEXTI
12 FOR I=0 TO &H17FF:VPOKE&H2000+I,31:NEXTI
20 RESTORE140:P=&HA000
30 READ A:IFA<>-1THENPOKEP,A:P=P+1:GOTO30
31 fori=0to255:pokep,&hed:pokep+1,&ha3:pokep+2,&hcb:pokep+3,&h87:p=p+4:nexti:p=p-2
32 pokep,&h15:pokep+1,&hc2:pokep+2,&h11:pokep+3,&ha0:pokep+4,&hc9
90 DEFUSR=&HA000:A=USR(0):beep:A$=INPUT$(1):goto90
140 DATA &hf3,&haf,&hd3,&h99,&h3e,&h40,&hd3,&h99,&hfb,&h21,0,&h88,1,&h98,0,&h16,&h18,-1