[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Way to read Apple II disks on a PC?



Bryan Parkoff wrote:
"Sean Fahey" <a2fan@hotmail.com> wrote in message news:_7oMe.3157$Hn3.2339@newssvr23.news.prodigy.net...

"Ed Eastman" <noone@nowhere.net> wrote in message
news:ddspoj$ogj$1@unlnews.unl.edu...


It was pointed out that I could read the 'back' of an A2 flippy diskette
if I opened the diskette and turned the media over inside the jacket.

You can't just flip the drive over?
<ducking and running>

You can't. If Apple II disk has data on both sides. It is because PC drive has to detect the top disk's hole as the hard sector locator. PC drive should be able to read both sides at this time. I believe that EDI software tells the head arm to read top side and bottom side. I am sure that it is not always reliable. It may have gone wrong and data may be corrupted, but it is not always guarantee to be perfect.

Bryan Parkoff



Unfortunately, the heads are not directly above/below each other on a PC drive but are offset by a few (half) tracks, meaning you can't read the first track or two of the back of the Apple disk using the PC drives second head.

We have the same problem on the Commodore disks, which are similar in that they both use GCR and 300rpm double density disks. The syncs and weak bit handling are different enough to make the drives incompatible, but we have the same problems reading the backside on a PC drive.

Pete Rittwage
C64 Preservation Project
http://rittwage.com/c64pp