PURPOSE: To decrease the number of terminals which are used to a microcomputer, by combined-using the same input terminals of the microcomputer, for both the output signal of a cassette detecting circuit and the command signal supplied from a stop switch.

CONSTITUTION: The stop command signal (a) delivered from a stop command input circuit 2 is fed to a terminal A of a control circuit 1. Thus the circuit 1 stops the running of a magnetic tape. In case a cassette is not set at a prescribed lower position when no signal (a) is delivered, the signal (b) given from a cassette detecting circuit 3 is fed to an input terminal A of the circuit 1. As a result, the running of the magnetic tape is also stopped by the control 1.