10MODE 1
   20PROC_set_colour(1,2,2,1)
   30PROC_circle
   31GOTO 10000
   40END
   50 
   60DEFPROC_circle
   70DIMP%63:FORI%=0TO15:READP%!(I%*4):NEXT:FORQ%=0TO2STEP2:R%=1023*-SGN(Q%<2):F%=512:G%=R%:MOVE511,R%:MOVE511,R%:FORS%=0TO1:FORA%=0TO63:IFS%THENZ%=P%?(63-A%)ELSEZ%=P%?A%
   80X%=Z%DIV16:Y%=Z%MOD16:Y%=Y%+(16*((Y%AND8)<>0)):Z%=X%:X%=(1-S%)*X%-S%*Y%:Y%=(1-S%)*Y%-S%*Z%:G%=G%+Y%*SGN((Q%>1)+.5):F%=F%+X%*SGN((Q%=1ORQ%=2)+.5):PLOT 85,1024-F%,G%:PLOT85,F%,G%:NEXT,,
   90DATA &60606F60,&606F6070,&6F606F7F,&6F6F6F7F,&6F6F7E6F,&6E6E6F6E,&6E6E6F6E,&6E6E6D6E,&6D6E6D5E,&5D6D6E5D,&5D6D5D6D,&6D5D5C6D,&5C5C5D5C,&5C4C6C5D,&5C5C5C5C,&4C5B5C4C
  100ENDPROC
  110 
  120DEFPROC_set_colour(Colour1,Colour2,Colour3,Colour4)
  130   VDU 18,0,64
  140 
  150   pair0 = (Colour1 AND 2) OR ((Colour2 AND 2) DIV 2)
  160   pair0 = pair0 * 4 + pair0
  170   pair1 = ((Colour1 AND 1)*2) OR (Colour2 AND 1)
  180   pair1 = pair1 * 4 + pair1
  190   pair2 = (Colour3 AND 2) OR ((Colour4 AND 2) DIV 2)
  200   pair2 = pair2 * 4 + pair2
  210   pair3 = ((Colour3 AND 1)*2) OR (Colour4 AND 1)
  220   pair3 = pair3 * 4 + pair3
  230 
  240   VDU pair0*16 OR pair1
  250   VDU pair2*16 OR pair3
  260   VDU pair0*16 OR pair1
  270   VDU pair2*16 OR pair3
  280ENDPROC
10000VDU 5
10020ON ERROR GOTO 10110
10030FOR X=0 TO 39
10040   PROCscroll(X,0)
10041   PROCwipe
10090NEXT
10100PROCscroll(0,0)
10110PROCmove(0,0)
10120END
10130DEFPROCscroll(I,J)
10140I=I MOD 80:J=J MOD 32
10150Xbase = I:Ybase = J
10160I=&3000-(I*8*2)-(J*640)
10170IF I<&3000 THEN I=I+&5000
10180IF I>=&8000 THEN I=I-&5000
10190*FX19
10200VDU 23;12,I DIV 2048;0;0;0
10210VDU 23;13,I MOD 2048 DIV 8;0;0;0
10220ENDPROC
10230DEFFNjoyleft
10240=(ADVAL(1) DIV 64) < 256
10250DEFFNjoyright
10260=(ADVAL(1) DIV 64) >512+256
10270DEFFNjoydown
10280=(ADVAL(2) DIV 64) < 256
10290DEFFNjoyup
10300=(ADVAL(2) DIV 64) >512+256
10400DEFPROCwipe
10410   MOVE 1280-(1280 DIV 40),0
10420   MOVE 1280-(1280 DIV 40),1023
10430   PLOT 80,1280,0
10450   PLOT 80,1280,1023
10460ENDPROC