A program executes 10,000 instructions. It alternately reads data from the floppy and writes data on the floppy after every 1000 instructions. The user carelessly removes the diskette when the program has completed 3100 instructions and insertes a different diskette. If this mistake is unchecked, it will result in reading wrong data and overwriting the second floppy. Hence, the operating system should detect this abnormal situation. Suggest a hardware support (present in the controller/device/ interface) that can be used to alert the operating system.