2000 PRINT"PLEASE CHANGE DISKS."
2010 OPEN 15,8,15
2020 GOSUB 3000: IF A<>0  THEN 2020 :REM  WAIT FOR DISK TO BE REMOVED
2030 GOSUB 3000: IF A<>16 THEN 2030 :REM  WAIT FOR NO DISK IN DRIVE
2040 GOSUB 3000: IF A<>0  THEN 2040 :REM  WAIT FOR DISK TO BE INSERTED
2050 FOR D = 1 TO 1500: NEXT: CLOSE 15
2060 PRINT"OK, THANKS!"
2070 END
2080 :
3000 PRINT#15,"M-R";CHR$(0)CHR$(28)CHR$(1):GET#15,A$:A=ASC(A$)AND16:RETURN