I am in the planning stages of a similar project myself. I will be building a homebrew computer around a 20mhz Z80 (Yes there's 20 mhz now!) and would like to directly interface a 3 1/2" floppy drive. I have no need for PC compatability (In fact if i could just write a block of data say 32k or so and read it back later that is all I really need) I do not wish to use any form of controller as the whole point of this project is to homebrew as much of the system as possible for challenge/education purposes.

If anyone could email me any tips/information on floppy interfacing, it would be appreciated. As it stands right now all I have to work with is the pinout of the 34 pin cable. I have not been able to find any information as to theory of operation/etc.