Z80 home brew with FDC

------REPLY------ Hi Alexis, Rich, Thanks Rich! Yes, Rich has the right command sequence but you also need to send the C, H, R, N to the i8272 for each sector during the execution phase. It is not very intuitive but I got it working last night on my test bench and confirmed it is working with Dave Dunfield's IMD program (Thanks Dave!) and the Catweasel with CW2DMK (Thanks Tim!). For some odd reason it also requires a leading $00 to format correctly which I don't understand either. Basically, it is like writing a sector but you feed it sector metadata as it goes around the track formatting sectors. Note, during execution phase it is not like feeding the MSR/data registers like during the command/result phase. The whole NEC765/i8272 process is kind of screwy IMO and I am struggling to get my brain around it. I have sample code if you'd like to see it but it is an awful mess right now. As for the data separator, I am using an FDC9229 although you could use a FDC9239 I think. The chips are still available but not exactly common. You have to look but you can find them. I have some pointers if you'd like. Actually, Alexis, you'd be the perfect guy for building your own Z80 home brew FDC as you already have done most of this on your other projects. You did an awesome job on your home brew 8080 a while back and your other projects have been great too. Your experience would be a lot of help to the project in putting out a design that not only works but is reliable and flexible.