You know, it would be a lot easier to help you if you'd be less oblique about what it is you're trying to do.
Maybe something here will help you. Unless you supply more information there's just no where else for this thread to go, pretty much.
ftp://ftp.netbsd.org/pub/NetBSD/misc/wrstuden/Apple_PDFs/
I would attempt to help explain what PH0-3 are for but I'm just stumped at what level to go to in order to reply to a statement like: "What are all these modes and stuff? I don't get it...". To really oversimplify, when you're using a "smart" floppy drive like the ones in a Macintosh (vs. the old raw stepper motor interface drives like the Disk II) they're essentially address lines for selecting a which bit to read or write in the drives' status/control register. (Does that help, or is that just gibberish?) Granted that description in based on the *IWM* documentation, but: The only difference apparent from scanning the SWIM documentation is in ISM mode it's possible to set the Phase0-3 lines to be inputs as well as outputs, but at no point I could find in the document does it explain *why* you would set them as inputs. Whether that functionality is actually used or if it's just something the hardware can do (possibly to allow the use of "dumber" floppy drives without status registers?) might be something someone could answer if you'd be more clear about *WHY YOU WANT TO KNOW*.
(If you could find a technical manual for an Apple Superdrive floppy that would also probably answer the "output only or R/W" answer as well. I'm sure it's out there, but I know it's not worth my time looking for it at this juncture.)
Maybe something here will help you. Unless you supply more information there's just no where else for this thread to go, pretty much.
ftp://ftp.netbsd.org/pub/NetBSD/misc/wrstuden/Apple_PDFs/
I would attempt to help explain what PH0-3 are for but I'm just stumped at what level to go to in order to reply to a statement like: "What are all these modes and stuff? I don't get it...". To really oversimplify, when you're using a "smart" floppy drive like the ones in a Macintosh (vs. the old raw stepper motor interface drives like the Disk II) they're essentially address lines for selecting a which bit to read or write in the drives' status/control register. (Does that help, or is that just gibberish?) Granted that description in based on the *IWM* documentation, but: The only difference apparent from scanning the SWIM documentation is in ISM mode it's possible to set the Phase0-3 lines to be inputs as well as outputs, but at no point I could find in the document does it explain *why* you would set them as inputs. Whether that functionality is actually used or if it's just something the hardware can do (possibly to allow the use of "dumber" floppy drives without status registers?) might be something someone could answer if you'd be more clear about *WHY YOU WANT TO KNOW*.
(If you could find a technical manual for an Apple Superdrive floppy that would also probably answer the "output only or R/W" answer as well. I'm sure it's out there, but I know it's not worth my time looking for it at this juncture.)