10 SYS7*4096:PRINT"SHADES - FILTER CONTROL":PRINT"TO INCREASE FILTER PRESS +"
20 PRINT"TO DECREASE FILTER PRESS -"
30 PRINT"[145]FILTER =     [157][157][157][157]";(FAND255)
40 A=PEEK(203)
50 IFA=40THENF=F+1:SYS2265:GOTO30
60 IFA=43THENF=F-1:SYS2268:GOTO30
70 GOTO40