> Well, for now I'm just going to shut them all off and see if that solves some
> of my problems.
> 
> What interrupts, if any, does the kernel shut off when you go into a system
> call? The Mac side driver seems to shut off everything for good measure when
> you switch modes. I really think it's a resource sharing problem, prob. the
> RBV chip can't handle SCSI *and* deal with video if it's in the middle of
> one or the other.

I don't think the kernel disables any interrupts on entering from a syscall.

The SCSI drivers run at splbio, which is spl2, so your code won't (shouldn't)
get to run during an SCSI access. With just serial characters flying
around, you should be able to shut off interrupts for 52 us w/o problems.
For longer than that, we might start loosing bytes at 57600.

The current serial driver is designed to get the bytes and stash them
away (in the ring buffer), letting the kernel come along later and read
them when you (it) aren't in the middle of something. I'm interested to
know of any conflicts here.

Take care,

Bill