From: almesber@nessie.cs.id.ethz.ch (Werner Almesberger) Subject: Re: Device names (was Re: ttys2 not responding) Date: Mon, 13 Jul 1992 13:22:52 GMT
In article <710808938.F00117@remote.halcyon.com> Rob.Levin@f217.n3802.z1.fidonet.org (Rob Levin) writes:
> Well, far be it from me to splash water, doesn't the existence of
> /dev/fd0 and /dev/fd1 sort of render all this complication *moot*? Are
> there any situations where autodetect could *not* be used successfully?
> If not, are there any situations where one would *want* to use the more
> cumbersome forms simply for consistency purposes?
The auto-detecting floppy devices have been implemented with exactly
this in mind: reducing the need for fixed-format devices.
However, there are a few situations that they can't handle well:
- 360kB disks in 720kB drives (rare)
- 360kB disks in 1.44MB drives (very rare)
- 720kB disks in 1.2MB drives (very rare)
- situations, where the format has to be known before the first
access, e.g. low-level formatting
- floppy drives that have a broken media change detection
While I'm not sure, whether the fixed-format devices can handle all the
unusal formats I've listed (without kernel changes), they can at least
handle some of them. Of course, with the help of setfdprm, auto-detecting
floppy devices can use any format that is consistent with the design of
the device driver.
Because none of these problem situations are too common, it doesn't hurt
to have complicated names for the fixed-format floppy devices, as long
as it is more or less obvious what they mean.
- Werner
-- _________________________________________________________________________ / Werner Almesberger, ETH Zuerich, CH almesber@nessie.cs.id.ethz.ch / / IFW A44 Tel. +41 1 254 7213 almesberger@rzvax.ethz.ch / /_BITNET:_ALMESBER@CZHETH5A__HEPNET/CHADNET:_[20579::]57414::ALMESBERGER_/