Re: EDD Plus Project

[sicklittlemonkey <Nick.Westgate@gmail.com>]

On Jan 13, 3:53 pm, "Bryan Parkoff" <nos...@nospam.com> wrote:
> >> I deobt Apple II Disk Drive may work with PC via USB. It depends on the
> >> exact timing. You need to run on real Apple II in order to work with
> >> copy-protection schemes.
>
> >I'm sure you're correct about limitations of .NIB. But I would think
> >that anything that a real apple II could do, some firmware running in
> >a USB device could do just as well? What I imagined was a little box
> >with a connector for a disk ii cable on one end, and a USB connector
> >at the other. There would also be a little button on the box. When you
> >press the button, the microntroller starts the disk drive spinning,
> >then reads in each (full/half/ or quarter?) track in turn, and builds
> >up a .nib or .2mg or whatever format file which is stored on a flash
> >drive which is also embedded in the box. When the box is connected to
> >a USB host (e.g. a PC) then the file stored on flash is visible.
>
>     I know what you mean.  It is like to load all bits in one track and
> store it into RAM buffer before RAM buffer is ready to be transmitted
> through USB cable.  It is impossible to send the commands to Disk II
> controller card through USB cable.  The Disk II Drive and Logic Sequencer in
> the Disk II controller card require exact timing.  RAM buffer will not work.
> It can only work on real Apple II machine.
>     You can't imagine if you attempt to simulate copy-protected scheme in
> the Apple II emulator, some copy-protected scheme does not match the exact
> timing.  It will fail.
>     If you are smarter enough, you may try to overcome the limitation.

Jonnosan is talking about imaging the disk only. I think it would be
quite feasible to capture the disk data accurately enough for
processing into a .NIB (or successor) format.

Timing is not so critical as you think - this is exactly what the Disk
II controller card is designed to deal with. Think of the clock
differences between NTSC and PAL, or drive speed differences. Even the
EDD+ card uses a 7M clock that lacks the 65 (long) cycle jitter that
the Disk II controller is exposed to.

Cheers,
Nick.