Date   : Wed, 24 Mar 2010 21:39:22 +0000
From   : tim.fardell@... (Tim Fardell)
Subject: Re-using floppies

Pete Turnbull wrote:
> 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.

Sorry a bit off-topic I know, but does anyone happen to know what 
format the Epson QX-10 computer used, and whether the discs would be 
recoverable on a standard PC drive?

My original QX-10 disks have been stored in a damp environment for a 
few years, and show visible deterioration, and the QX-10 drives can 
no-longer read them :-(