4 Nov
2022
4 Nov
'22
12:44 a.m.
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-diskette…
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(a)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.