Date   : Sun, 17 Oct 2010 13:54:24 +0100
From   : mike@... (Mike Tomlinson)
Subject: Fw: DD & HD Floppies

In article <AANLkTi=sb6nLwsSW44tpmBwcgVHoMo59YLXF-xXOh-
c9@...>, Dave Curran <bbc@...> writes

>    Silly question, but I'm just taking a step back from this and 
>    thinking that instead of adapting HD disks to work in DD drives, 
>    what are the chances of getting standard 1.44M HD drives to work on 
>    the BBC??

IIRC, it could theoretically be done but timings would be very tight.
The disc controller chip would need to be changed for an HD-capable one,
which precludes using existing DFSes.

>    The ideal would be adapting one of the DFS's to work with 1.44M 
>    disks - unless any of them do already? Otherwise some hardware mod 
>    to use HD drives and disks as if they were DD drives and disks.
>    Double all the track steps and perhaps even repeat every write on 
>    the next track to increase the chances of DD compatibility?

DD and HD both use 80 tracks, so double-stepping wouldn't solve
anything.  

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