100 COLOR 15,0,0:SCREEN 11,0,0:VDP(10)=VDP(10)AND&H7F
105 K%=32:FOR Y%=0 TO 63
110 J%=32:FOR X%=0 TO 255 STEP 4
115 P%=Y%*256+X%
120 KL%=K%MOD8:KH%=K%\8
125 JL%=J%MOD8:JH%=J%\8
130 VPOKE P%+0,KL%:VPOKE P%+1,KH%
135 VPOKE P%+2,JL%:VPOKE P%+3,JH%
140 J%=J%+1:IF J%>63 THEN J%=0
145 NEXT X%
150 K%=K%+1:IF K%>63 THEN K%=0
155 NEXT Y%
160 Y%=0:J%=0
165 K%=0:OY%=-1
170 IF Y%<>OY% THEN LINE(0,0)-STEP(255,63),&HF,BF,AND:LINE(0,0)-STEP(255,63),Y%*16,BF,OR
175 LINE(4*J%+1,0)-STEP(0,63),&HF0,,XOR:LINE (0,K%)-STEP(255,0),&HF0,,XOR
180 K$=INKEY$:IF K$="" GOTO 180 ELSE OY%=Y%
190 LINE(4*J%+1,0)-STEP(0,63),&HF0,,XOR:LINE (0,K%)-STEP(255,0),&HF0,,XOR
195 J%=(J%+(K$=CHR$(29))-(K$=CHR$(28))) AND 63
200 K%=(K%+(K$=CHR$(30))-(K$=CHR$(31))) AND 63
205 Y%=(Y%+(K$="-")-(K$="+")) AND 15
210 IF TIME<2 THEN 210 ELSE 170