Ways to implement a selectable 3rd drive

[Jeff_Birt]

Thanks for the info about current draw, that helps. After looking through my parts bins I found I have some panel mount 8-pin DIN connectors (C64 power connector). I was able to sneak one in the filler for the fuse and conveniently the hole left by the top of the power switch is the perfect size for a USB-B connector. 

I guess now this leaves the extra three pins on the DB37 free. I get really motivated to make a small PCB to switch between and internal and external drive via a wire loop on the external FDD harness acting like a switch.

Thanks for your help!