On Wed, 21 May 1997 17:44:52 -0400 (EDT) 
 wonko@blackhole.arkham.net (Brian Hechinger) wrote:

 > this is such a scary statement.  just because Win95 can do it doesn't mean 
 > that a) it's possible for a "real" multitasking OS to do it and b) it's a
 > good idea.  keep in mind that Win95 is a kludged piece of junk.  i bet you
 > that Win NT (4.0 anyway) can't do shared IRQs.

...this is actually somewhat dependent on the bus.  PCI, for example,
will share IRQs, and it is safe for PCI to do so.  This is _not_ always
the case on ISA, and IT MAY DAMAGE YOUR HARDWARE.  Since it is _sometimes_
safe, NetBSD allows it.  As a general rule, though, if an IRQ is to be
shared, it must be share the same "type", i.e. edge with edge, level with
level, pulse with nothing.

Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                               Home: 408.866.1912
NAS: M/S 258-6                                          Work: 415.604.0935
Moffett Field, CA 94035                                Pager: 415.428.6939