Re: 3.5 inch floppy drive controller
If I have correctly understood your C5 has the same commands as for a tape drive, so the floppy controller emulates the old tape drive.
This controller looks more complex than the CPU.
Is your floppy controller wired to the X43 connector on the CPU?
Look at the X43 connector on the CPU, in the maintenance manual page 5.18 it says: wired from and to interface for cassette recorder, 5 V supply and signalling.
Unfortunately there is no description for the CPU connectors, one has to find out by measuring and back tracing with the opposite connectors which are described
in the manual only for the power supply points.
Here is the datasheet for the floppy drive:
It seems to be used in Amiga's and then the density is either 1 or 2 MB.
Repairing a drive: