Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!uunet!ogicse!qiclab!leonard
From: leonard@qiclab.scn.rain.com (Leonard Erickson)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Reading Mac diskettes on a PC
Message-ID: <1991May20.093104.11831@qiclab.scn.rain.com>
Date: 20 May 91 09:31:04 GMT
References: <16288@helios.TAMU.EDU> <1991May17.154148.6341@leland.Stanford.EDU> <1991May17.095903.314@biivax.dp.beckman.com>
Organization: SCN Research/Qic Laboratories of Tigard, Oregon.
Lines: 22

dahosek@biivax.dp.beckman.com writes:

<In article <1991May17.154148.6341@leland.Stanford.EDU>, aaron@jessica.stanford.edu (Aaron Wallace) writes:
<> Because Apple used a non-standard encoding method, and variable speed
<> drives, based on the old Apple II.  

<Actually, the II had straightforward 16 (or 13) soft sector
<formatting on its disks. It was the Apple Lisa (do any of those
<puppies still exist?) which introduced variable speed disk
<drives. They had special 5.25 disks with extra notches and slots
<and it sounded like it was singing when it wrote to the disk.

The encoding on an Apple II is *not* standard from any point of view except
Apple's. The used an oddball customized circuit instead of a standard floppy
controller. Thus, the disks are unreadable on "normal" equipment.

It'salso possible to do some weird and strange things with Apple disks
because of this. This is the basis of several copy protection methods.
-- 
Leonard Erickson			leonard@qiclab.uucp
personal:	CIS: [70465,203]	70465.203@compuserve.com
business:	CIS: [76376,1107]	76376.1107@compuserve.com