Abstract: A floppy disk driver intended to protect the disk center hole from damage when the disk is mounted. The arrangement includes a speed detection circuit for detecting a relatively low rotational speed of the disk and a control circuit for speeding up the disk to a higher rotational speed for the read/write operation in response to the detection of the lower disk speed, whereby the disk is protected from damage by being rotated at the lower speed when its center hole is held between the collet and spindle.

Abstract: A waveform equivalent circuit for correcting the asymmetry of the rising and falling slopes of an isolated signal waveform retrieved from a magnetic recording medium so as to restore an acute, symmetric isolated waveform. In operation, the input signal is phase-shifted and attenuated, and then added to the input signal to produce a smaller double peaked waveform, which is modified with an inverted and attenuated version of the input waveform. The input signal waveform is subtracted from the modified double peaked signal waveform to diminish both slope sections, and an acute, symmetric original signal waveform is recreated.

Abstract: A magnetic head loading apparatus serves to load a magnetic head on the surface of a disc-shaped magnetic recording medium rotating continuously so as to perform the recording and reproduction of data. The magnetic head is shifted from unload to load position by means of a drive means. In order to prevent damage to the recording medium due to the collision of the magnetic head with the recording medium, the drive means is so controlled as to cause the magnetic head to decellerate as the magnetic head approaches the load position.