Date: Sun, 3 Oct 1999 00:33:57 +0200 (CEST) From: Wilko Bulte <wilko@yedi.iaf.nl> To: freebsd-hackers@freebsd.org Cc: freebsd-hackers@freebsd.org Subject: Re: 2.88Mb floppies Message-ID: <199910022233.AAA56167@yedi.iaf.nl> In-Reply-To: <199910021904.VAA16526@dorifer.heim3.tu-clausthal.de> from Oliver Fromme at "Oct 2, 1999 9: 4:59 pm"
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As Oliver Fromme wrote ...
> Wilko Bulte wrote in list.freebsd-hackers:
> > As Oliver Fromme wrote ...
> > > I once programmed low-level FDC stuff under DOS, so I'm a bit
> > > familiar with this... The difference between 1.44 and 2.88 Mb
> > > floppies is that the latter use 36 sectors per track and twice
> > > the data rate (1 MBit/s). So the entry should look like this:
> > >
> > > {36, 2, 0xff, 0x1b, 80, 5760, 1, FDC_125KBPS, 2, 0x6c, 1}
> > >
> > > Actually, there should be a #define FDC_1MBPS FDC_125KBPS
> >
> > Eh, I guess you mean:
> >
> > {36, 2, 0xff, 0x1b, 80, 5760, 1, FDC_1MBPS, 2, 0x6c, 1} ?
>
> No, FDC_1MBPS is not defined (that's why I said that it
> _should_ be defined).
> Actually, FD controllers use a 2bit flag to indicate the
> transfer speed, and traditional controllers interpreted those
> four values as 125, 250, 300 and 500 kbps. Newer controllers
> dumped the 125 kbps support and interpret the same bits as
> 1000 kbps. So using FDC_125KBPS is OK.
Ah.. talking about confusing. It's been a long time since I
had to design a FDC on a SCSI adapter card. Project got scrapped too :-(
> Beware, I have not actually tried this with FreeBSD, and there
> might be bugs that prevent using 2.88 Mb floppies.
I hope to give it a quick try next week.
--
| / o / / _ Arnhem, The Netherlands - Powered by FreeBSD -
|/|/ / / /( (_) Bulte WWW : http://www.tcja.nl http://www.freebsd.org
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