Here's something right out of the Apple II FAQ:
07.007 Can I read Apple II diskettes on my PC?
Yes. There is a way for some PCs to read Apple II DOS 3.3 and
ProDOS 5.25"
floppies which are not copy-protected.
By "some PCs" I mean that the PC must have two floppy drives (only one has
to be a 5.25" drive) and it must be running MS-DOS or Windows 95, 98, or ME.
(It won't work with NT, 2000, and XP).
You also need a program called "DISK2FDI". (For a link to the program, see
Csa21MAIN4.txt.)
DISK2FDI reads the Apple floppy and creates a disk image (.do) on the PC.
These images will work on most emulators.
https://stason.org/TULARC/pc/apple2/faq/07-007-Can-I-read-Apple-II-diskettes-on-my-PC.html
Oh yeah, I remember now:
http://www.oldskool.org/disk2fdi/
It requires two drives, where one drive has a PC-DOS formatted disk in it,
and then switches to the other that contains the subject GCR disk. Cool
hack.
Sellam
On Thu, Nov 3, 2022 at 5:16 PM Fred Cisin via cctalk <cctalk@classiccmp.org>
wrote:
> On Thu, 3 Nov 2022, Sellam Abraham via cctalk wrote:
> > There was a project someone did years ago where you can read GCR disks in
> > an unmodified PC drive by first inserting a PC formatted disk to get
> synced
> > and then swapping in a GCR encoded disk, then it can actually read the
> raw
> > pulses and they get decoded in software. I forget the website where the
> > project can be found but a web search will hopefully turn it up.
>
> There are some strange tricks that you can do to fool the system and get
> it to read some stuff that is NOT IBM/WD sector/track structures.
>
> For example, Amiga is MFM data stream, but without IBM/WD sector/track
> structures. You can fool the NEC FDC into seeing it, in several ways, one
> of which is to switch drives in mid read, and/or to read a "long" sector.
>
> I never succeeded with any of the tricks for Apple2 GCR.
>
>
> About 35 years ago, I did the file system code to use with an extra board
> ("Apple Turnover") to go between the FDC and the drive, for Apple2 disks
> (Apple-DOS 3.2 (13 sector), 3.3 (16 sector), Softcard CP/M, P System, and
> ProDos) It never worked well, and the publisher got in too far over their
> heads, and I had to have a lawyer shut them down.
>
