Floppy disc reader/writer status report

Rob wrote: I'm near Leeds (the one in Yorkshire, not the one in Kent). I've got an 80T drive already - all I really need is a 40T to complete the set. And that's just because 40T drives have a larger head - the whole "40T reads 40T discs better than an 80T unless they've been formatted/written in an 80T" thing. I've just done Dave Dunfield's 300RPM hack on my YE-Data drive (after some multimeter probing) and it seems to be working. I still need to fit it into a PC and see if it can read a BBC floppy, but you can certainly hear the difference in speed (and see it in the index pulse delay on a scope). It should do. You'd just need to change the read clock rate as the data rate slowed down, assuming you were using a standard 300 or 360RPM drive. The same goes for the oddball Amiga (IIRC) drives that change speed depending on head location - you just need to slow down the read clock so that the slower tracks don't overflow the track timing counter. I'm going to try and add some logic that clips the timing counter at 0x7F if it tries to overflow - that should make it a little easier to find out if the read rate was too slow. Equally, lots of low values mean you've probably got the read rate too high. AIUI, the Catweasel doesn't do this.. :) I'd want to get a couple of 'blank' discs formatted on the machine to play with before reading out the contents of the discs. That way the algorithms and timing can be perfected without risking ruining irreplaceable media (the 'binder absorbing moisture and losing grip' issue and so forth). -- Phil. | (\_/) This is Bunny. Copy and paste Bunny classiccmp at philpem.me.uk | (='.'=) into your signature to help him gain http://www.philpem.me.uk/ | (")_(") world domination.