The external floppy drive that I was using with my CDTV died and replacements were a little expensive (ok, they weren’t that bad but I was impatient). So I figured, how different could an Amiga FDD be from a PC one?
Turns out there are a couple of differences, the signals on pin 2 and pin 34 are reversed (Density Select, Ready Change) and the drive needs to identify as DS0 if it’s the internal drive on a normal Amiga or the external drive on the CDTV (PC drives don’t because they’re generally picked up using cable select).
How this works will vary depending on your drive, but for my Sony model it was very simple. It requires two wires, two track cuts and a jumper change.
Basically we need to cut the connection that pins 2 and 34 are on, and then put a wire from 2 to a solder point that was pin 34‘s original destination and between 34 and a solder point that was pin 2‘s original destination.
You should be able to work out where they are from the pictures, be careful when cutting to only cut the one track and don’t cut yourself.
If you want to revert the drive you can just run a wire between the pins and their original solder points.
The jumper is at the back of the drive, next to the motor. If it’s on 0 and 1 (nearest the motor) then it’s set to be DS0, if it’s on 1 and 2 then it’s DS1. If you want it to be internal on an Amiga or external on a CDTV then it needs to be DS0, if you want it external on an Amiga then set it to DS1.