Hi,

Thanks for the nice explanation.  I wasn't trying to be 
short, just my faulty memory again :-)

cheers

bruce

On Tue, Apr 20, 2004 at 01:17:07PM -0400, Nyef wrote:
> On Tue, Apr 20, 2004 at 03:10:45PM +0000, Bruce O'Neel wrote:
> > Hi,
> > 
> > I don't think the floppy has been solved.  I seem to remember that
> > some docs were released that would explain how the hardware worked,
> > but, no one actually did the work.
> 
> It's actually a little more complex than that.
> 
> Some people actually have the official Apple documentaion, but have
> been asked not to distribute it too widely. Haven't heard much from
> them about actual floppy drivers, though. I think maybe they have
> lives or something. ;-)
> 
> I, some time ago, did my own research and wrote up the documentation
> that is at http://www.dridus.com/~nyef/documents/swimnotes.txt (but
> is now a little out of date as I learned some stuff since then).
> 
> I also tried to write a floppy driver (the code for which is around
> -somewhere-, but I forget where). It involved a major restructuring
> of the IWM driver to work in support for the SWIM chips and so on,
> but while I didn't break the IWM support (or the 800k disk support)
> I never did get it to read the address mark from a 1.44 meg disk.
> 
> This was some time ago. Specifically, it was before 1.6. Problem
> is, trying to do this sort of development on an '030 is rather
> frustrating, especially when you don't know exactly what's going
> wrong, and trying to figure out how the hardware worked by poking
> at it with Pocket Forth wasn't going very well...
> 
> Anyway, there things stayed for a while. Then I got the bright idea
> of taking the IOP code from the universal ROMs and using -that- and
> a 6502 emulator to get a look at the SWIM chip from another angle.
> Looking at the emulator code, I had gotten part of the interface
> for communicating with the host working, and the SWIM initialized
> by the control code, but hadn't gotten much beyond that. I also have
> some unreleased documentation on the IOP interfaces based on the
> IOP interface code in the Linux kernel, the IOP code (what little
> of it there is) in the NetBSD kernel, and my own investigations.
> 
> I think what it amounts to is that the people with the real docs
> are too busy with other stuff, and I occasionally take a stab at it
> but keep losing interest and moving on to other stuff, and nobody
> else has really been attacking the problem (hey, sort of like the
> standalone boot stuff, which I still have to tidy up and release).
> 
> I'm getting the impression, however, that whatever happens we've
> missed the window for getting this stuff into 2.0, even if
> everything is figured out and made working over the course of the
> next week (which probably isn't going to happen even if we haven't
> missed that window).
> 
> --Alastair Bridgewater

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