10 CLS:POKE 30744,1
15 REM *** USE INTERAL CH
20 OUT 32,0
30 FOR X=0TO255:POKE 28672+32*8+X,X:NEXT
40 FOR D=1TO900:NEXT
50 REM *** ENABLE EXTERNAL CH
60 OUT 32,32
70 FOR D=1TO900:NEXT
80 REM *** DISABLE SEMIGRAPHICS
90 OUT 32,160
100 FOR D=1TO900:NEXT
110 GOTO 20
