Tarbell is making me insane

15 Nov 2007

...
  This faster
signal might be better for the disk drive?  
 Potentially.  Remember FM floppy recording was passe' by the early
 80s with every one needed far greater space.  It want even a 
 consideration buy time PC 3.5" floppies hit the street. 
As I understand it, FM at 125bps  has (only) pulse spacings that can occur 
in MFM at 250kbps. The latter has some other spacing too, of course, but 
the point is that unless you're trying to be awkward, it's impossible to 
make a drive that will correctly handle any MFM data at 250kbps that will 
not also correctly handle FM data at 125kbps. (About the only way you 
could do it is if the drive tries to decode the data back to user bytes 
and then re-encodes them onto the disk in a totally different way. I know 
of know floppy drive that ever tried something like that!). 

There should be no problem at all in using a 3.5" DD floppy drive with 
the FM data stream that uou'd have sent to an SA400.

-tony

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Tarbell is making me insane