Re: usb disk controller to read c64 disks.

On Tuesday 20 September 2011, you wrote:
> >> The Kryoflux hardware idea is fine. Software support tends to lag. It
> >> can't read the back side of disks, for example.
> > 
> > and it will never be able to =) although they claim something like that,
> > you will have a very hard time to find a pc drive mech which can read
> > tracks below track 4 on the flipside. you will require the same drive
> > "hack" to read flip disks as you will need when working with the
> > catweasel (which works by exactly the same principle)
> 
> Could you elaborate some more on the problem that you describe (track 4
> flipside) or provide some pointers ?

leaving the index hole problem aside (this can be solved, and actually only 
matters if you want to flip disks in a standard pc mech), its a mechanical 
problem... on an actual "flip disk" (like what you get when you format both 
sides of a disk using a 1541 by flipping it), tracks are exactly at the same 
location on both sides of the disk surface.
now in a typical double-sided drive mech, the top head is offset by (about) 4 
tracks (also for example in a 1571) for - i guess - manufacturing reasons.
and if you seek to the outher edge of the disk ("track 1") the top head does 
not reach the position where the actual track 1 would be located on a flip 
disk, and moving even further is restricted by the drive mechanics (for 
obvious reasons, i guess). so to be able to read a "flip disk" in a double 
sided mech, you would need to find one where you can hack the mechanics to 
allow seek to "track -4".

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