Re: Apple II <-> Commodore 64/128 disks?

[nathan@visi.com (Nathan Mates)]

In article <5rtsap$p8v@clarknet.clark.net>,
William McBrine <wmcbrine@clark.net> wrote:
>The Apple II FAQ states that Apple disks are incompatible with IBM PC
>drives, and vice versa, because Apple drives use GCR encoding, where PC
>drives use MFM. This got my attention, because the Commodore 64's 1541
>drive also uses GCR -- and the 128's 1571 drive is a dual mode drive, so
>it can exchange data with PC drives. (The MFM mode was originally meant
>for use with CP/M, but can work with MSDOS disks, too.)

   The Commie drives have a microprocessor builtin, making them
capable of reading both MFM and a form of GCR. The Apple II 5.25"
drives are considerably 'dumber', requiring the host computer to take
care of most of the timing requirements, decoding, etc. Basically,
without rare addon hardware, the Apple II can't read other platforms'
disks. The C64 might be able to do more simply by starting with
better specs.

Nathan Mates
--
<*> Nathan Mates http://www.visi.com/~nathan/      <*>
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