Subject: Re: Breaking binary compatibility for /dev/joy
To: Jared D. McNeill <>
From: Perry E. Metzger <>
List: tech-kern
Date: 04/17/2002 10:32:25
I would suggest that you post a proposal for the new interface so that
people can get an idea of whether they think it is one that will last
without having to be rev'ed again. I'd also suggest checking what
other OSes (FreeBSD, Linux) do for this, so we don't become mindlessly
software incompatible. It is reasonable to be incompatible if there is
cause, but it is not useful to be incompatible gratuitously.

(BTW, why wouldn't USB joysticks end up with a /dev/ujoy with a
similar interface? I don't understand your USB comment.)

"Jared D. McNeill" <> writes:
> On Wed, 17 Apr 2002, Hubert Feyrer wrote:
> > On Tue, 16 Apr 2002, Jared D. McNeill wrote:
> > > I've added 4-button support to the analog joystick driver, but that
> > > required adding two more items to struct joystick (for the two extra
> > > buttons).
> >
> > Why just go to 4, not something like 16 or 32?
> It's a physical limitation of the old joystick interface (4 buttons only
> work if only one game pad is plugged into a controller, because it uses
> the bits for the second controller's 2 buttons as its 3rd and 4th).
> For more buttons, we have USB joysticks :)

Perry E. Metzger
NetBSD: The right OS for your embedded design.