[Coco] Drive issue

[Gene Heskett]

On Friday 13 March 2015 21:49:38 Daniel Campos wrote:
> Seeking counsel with the disk drive masters here. :-)
>
> I'm trying to dump some very very old disks that I grabed with a
> friend to my CoCoSDC, but I think I have a problem in my hands...
> I have a double drive unit that has two TEAC FD-55FV-13-U drives.
> These appear to be 720Kb drives (the fabled DSQD drives). I can DSKINI
> perfectly and SAVE and LOAD any DD disks on them BUT I can not read
> any disk originally created on a 180Kb drive.
> There is any way I can make these drives read correctly the disks
> created on an original CoCo drive ?

Those are 96 tpi drives.  The originals are 48 tpi. If everything else is 
in calibration then its a simple matter to double step the drive so it 
emulates the track to track spacing of the 48 tpi drive. I haven't a 
clue how to do that from rsdos, but its a piece of cake if using nitros9 
as its a set a bit option in the descriptor.  If you pull the nitros9 
repo with hg, then consult the file superdesc.asm file for a description 
of what you'd feed dmode /nameofdrive to set this double stepping flag.

> Thanks!
> Daniel

Cheers, Gene Heskett
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