Subject: Re: Audio and Floppy drivers
To: None <,>
From: Olaf Seibert <>
List: amiga-dev
Date: 02/15/1994 10:47:39 (Brad Pepers) wrote:
> I'm not sure about the audio drivers but I am working on a floppy
> driver. I have it kind of working (will read data most of the time)
> but its in pretty rough shape right now. I had asked mw (did you
> get my mail?) and ... (can't remember who else) for some floppy
> driver code someone else has done. I was hoping looking at someone
> elses code would help me see whats wrong with mine. No word back yet.

I don't know if it would be of any help, but you could take a look at
my messydisk.device, part of MSH 1.30 (available from aminet ftp sites).
It uses trackdisk for stuff like seeking, but it does (under 1.3) its
own disk DMA, which works fine. It then proceeds to do its own pc-style
MFM decoding, so for Amiga format disk you'd have to do that somewhat
different. If you're interested, I could contribute some twice as fast
MFM encoding/decoding functions, the same as those in the commercial
edition of MSH, and miscellaneous small bug fixes.

> Tracks are only read properly once out of every five or so tries (I
> think it is something to do with the sync not working).

The wordsync is used in MSH, and its use is rather simple. Just put
the sync word in the DSKSYNC register and set the WORDSYNC bit in
the appropriate control register. That's all there is to it. But
be sure to request a read of about (1 track + 1 sector), because
the first sector you get might be incomplete (there is a sync after
the sector header, at least in pc formats, so you might have a whole
sector without its identification).

___ Olaf 'Rhialto' Seibert       D787B44DFC896063 4CBB95A5BD1DAA96
\X/ There are no lemurs in this post