10 X=2:Y=7
20 FORJ=2TO11STEP2:POKE53281,J:POKE53280,J
30 FORI=1TO40STEP2
40 POKE1023+I,81:POKE55295+I,X:POKE1024+I,81:POKE55296+I,Y
50 POKE2024-I,81:POKE56296-I,X:POKE2023-I,81:POKE56295-I,Y
60 NEXTI:POKE53281,J+1:POKE53280,J+1
70 FORI=1TO23STEP2
80 POKE1984-40*I,81:POKE56256-40*I,X:POKE1984-40*(I+1),81:POKE56256-40*(I+1),Y
90 POKE1063+40*I,81:POKE55335+40*I,X:POKE1063+40*(I+1),81:POKE55335+40*(I+1),Y
100 NEXTI
110 Z=X:X=Y:Y=Z:NEXTJ
120 POKE53281,6:POKE53280,6