Taken from Happyharddrive.lha on aminet:
5.1a) We will first deal with having no drive DF0:, as this is an easier solution, once you know what you are doing.
Get the ribbon cable from the floppy drive, and with a piece of wire, connect pin 10 to pin 2. You can just stick the wire into the holes, and that should make a connection. What this does is fools the amiga into thinking there is never a disk in DF0:, but that it does work. Once this is done, take the ribbon cable and fold it triangularly so that the cable fits underneath where the floppy drive was.
Technical background to 'No DF0: hack
This pulls DISKCHANGE low when DRIVE SELECT 0 is low. What this means is that when the amiga polls the disk drive to say 'hello, are you there and is there a disk in?' it says 'hello, yes i am and no there isn't.'
Originally we had tried just pulling READY low permanently, but this made READY low all the time for all drives.
This meant the amiga detected DF0, DF1, DF2 and DF3 whether they were there or not. Then we tried the same with DISKCHANGE, and this detected the right number of drives, but did not let any of them signal a disk.
So it was only when we found the drive pinouts in Dick Diederik's PCFloppy2Amiga project, that we could link DRIVE SELECT 0 straight to DISKCHANGE, thus allowing any external drives to be used, but disabling DF0 and avoiding any wait states.
So there you go, the easiest, cleanest and best solution.
-Paul
