Re: Reading apple disks on PC

[pausch@saaf.se (Paul Schlyter)]

In article <yLtQa.13001$D%1.10374@nwrddc01.gnilink.net>,
Michael Pender <mpender@hotmail.com> wrote:
 
> I've been told that it is 'impossible' to read Apple-formatted 3.5"
> disks on a PC because of the difference in formats.  However, since
> there are tools such as TransMac, MacDrive 98 and MacOpen 2000 that
> can read Mac 3.5" HD floppies on PCs, the argument that it is
> 'impossible' seems a little less persuasive.
>
> If there really is a limitation that prevents reading Apple-formatted
> 3.5" DSDD disks on a PC's 3.5" drive, I would guess that it is
> related to the variable spin rates of the Apple's 3.5" drive.  Can
> anyone point me to a reference on the variable speed drives?
 
The incompatibility in disk format which makes it impossible to read
Apple disks in standard PC hardware is at the lowest-level encoding:
the Apple II used GCR whihe the PC uses MFM.  Early Macs used GCR
too; later MFM disks were used by Mac but a lot of Macs have floppy
drives capable of reading GCR disks too.  PC floppy drives have
never been able to read GCR disks and will never be.
 
That's why it's impossible to read Apple II disks on a PC although
it can be read on many Mac's: you just cannot write software to read
an Apple II disk on a PC (assuming standard PC hardware is used).
 
Of course there's a way around this: get hardware for your PC which
is capable of reading GCR disks.  In this case you must get a floppy
disk controller which can handle the GCR format -- do a web search on
"Catweasel" for a company which manufactures such floppy disk
controllers.  They're somewhat expensive though.....    ...or build
your own hardware...... :-)
 
However, short of getting new hardware for your PC, there's no way
to read an Apple II disk on your PC.
 
-- 
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