Date   : Wed, 24 Mar 2010 20:49:10 +0000
From   : pete@... (Pete Turnbull)
Subject: Re-using floppies

On 24/03/2010 19:32, Dr. David Alan Gilbert wrote:
> * Mike Pepper (profpep@...) wrote:

>> The Apple ][ and the ACT Sirius both used variable speed drives, making
>> copying something of a nightmare. I need to resurrect an Apple ][ soon to
>> copy up some old Apple Syntauri music discs, (Joy!)

Actually the Apple ][ used a standard fixed-speed 300rpm drive 
mechanism, but it uses custom Apple electronics to implement a unique 
GCR recording scheme, which is quite different to FM or MFM and 
difficult to decode on anything else.  The Sirius and some later Apple 
systems such as early Macs do indeed use variable-speed though. 
Commodore drives achieve the same end by changing the data rate on 
different parts of the disk.

While no standard controller can handle Apple GCR, there are other ways. 
  One obvious way to read Apple disks on a PC or similar system would be 
to use a Catweasel card, but I'm not sure what state the Catweasel 
software is in these days.  Another way is to use a Trackstar card, 
which is sort of like an Apple ][ on a PC (ISA) card, and allows file 
transfer, I'm told (never had one, never tried it).  However, despite 
various experts stating that you can't handle Apple ][ disks on a 
standard PC, I recall something on t'internet about a trick to doing 
exactly that a year or two back.  Needless to say I can't find that in 
my bookmarks, but I'll ask on ClassicCmp, if anyone is interested.

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York