Use Locksmith Fast Backup to get a copy of the original disk. With a disk editor look at: track $01 sector $0B byte $E0 change $A2 $0F - LDX #$0F $B5 $50 - LDA $50,X $48 - PHA $BD $E5 $07 - LDA $07E5,X to $AD $E8 $C0 - LDA $C0E8 $68 - PLA $68 - PLA $18 - CLC $60 - RTS $0A this can be any value (at least I think so) sector $0F byte $00 change $4C $69 $A0 - JMP $A069 to $18 - CLC $60 - RTS $DD this must be $DD to keep the checksum happy.