(*) If you want a true READY signal, you'll have to find which pin on the square FDC controller it's produced. The READY signal will be steady at around +5 V when no disk is in the drive (motor idle) and will drop to 0 V about half a second after a disk has been inserted (motor at full speed).
Once the READY pin on the controller chip has been identified, you can connect it directly to the (otherwise isolated) pin#34 and skip the diode altogether.
Are you sure about +5V ?
I found a pin which has no voltage at all but loads Skweek without any problem.