Re: How do I add firmware to a card?

[dempson@actrix.gen.nz (David Empson)]

Alex Freed <alexf@mirrow.com> wrote:

> "David Empson" <dempson@actrix.gen.nz> wrote in message 
> 1hsc1jh.1hqbl6aapwbr5N%dempson@actrix.gen.nz">news:1hsc1jh.1hqbl6aapwbr5N%dempson@actrix.gen.nz...
> >>
> >>   I wonder if the Unidisk could be used as a co-processor,
> >> doing non-disk access computations?
> >
> > In theory, yes. It would be a rather pointless exercise, unless you were
> > transferring a relatively small amount of data, doing a long and complex
> > calculation (with the Apple II doing something else at the same time),
> > then transferring back the result (also a relatively small amount of
> > data).
> >
> > The overhead of the data transfer wipes out any gain in having access to
> > a second processor, except when the computation time outweighs the
> > transfer time.
> 
> One application that comes to mind is on-the-fly encryption of
> data going to/from the disk. The usefullness of this in A2 context
> is a different story.

Even then, you don't gain much by doing it in the UniDisk 3.5, unless it
really is running at 2 MHz - in that case it would be able to encrypt
the data twice as fast as an unaccelerated Apple II.

One could argue that doing the encryption in the UniDisk is harder to
crack, because the code doing the encryption has to be downloaded into
the drive, but that code has to exist on the Apple II in the first place
to get it onto the drive, so reverse engineering would still reveal the
algorithm.

-- 
David Empson
dempson@actrix.gen.nz