Re: Hardware musings

["mdj" <mdj.mdj@gmail.com>]

Mark McDougall wrote:

> I'm not familiar with Apple II protection schemes, but I do recall some
> early PC protection schemes involved the creation of a floppy with some
> sort of hard error that could *NOT* be duplicated on a standard end-user
> floppy disk drive. I can't recall the exact details, but it may have
> involved physically altering the media surface in a specific place/manner?!?

Not sure of how such things were done, but the PC drive is somewhat
more 'intelligent' that the Apple II unit, and essentially incapable of
writing 'bad' data by itself.

The Apple II's essentially 'soft' design means that much lower level
disk information is software visible. The upshot of this being that any
erroneous data that could be written by some as yet undiscovered disk
duplicator could be approximated by an actual Apple II drive.

Matt