Hello !

> I AGREE!!!! When I get my PowerMac (a CHRP or PPCP or whatever) w/ ISA,
> I'm going to look at options for adding a second CPU, in the hopes
> of getting NetBSD up on a multi-head. :-)
> 
> There's a lot of work between here and there. Maybe one step would be
> to agree on some sort of semaphore system, or some general framework
> for SMP, even if it's a ways off.

As much as i know about realtime-os, it is a very good idea to use
semaphores. Think it is the only possibility for some things.
Not even SMP.

> I'm not sure about the SMP SE/30, though, as I'm not sure if the accelerators
> have the hardware to let both CPU's run at once, and can coordinate boot
> up. I'm not sure how exactly an SMP machine boots.

I think this won't work at all, because the accelerators for 68k-macs
disable the onboard cpu. And I think the accelerators don't have the
curcuits to support two cpu on one bus. But this only what i believe i
don't know it exactly.

I've read about an accelerator for the 6100, 7100 and 8100 that will made
this Macs to an SMP-machine, but don't know where i read this.

> > Also, some things simply require guaranteed real-time response from the
> > system (e.g. writing a CD-ROM with a CD-R drive, or schlepping bits to an
> > audio device for playback) to work really right. We're going to have to
> > clean up not just the device drivers (frankly, it won't be enough, long
> > term, to simply say, "Well, then, don't use the tape drive when you're
> > writing a CD-ROM!"), but also modify the scheduler so that, aside from the
> > entirely too simple "nice" facility, the system can guarantee an
> > arbitrary-sized CPU time slice at particular intervals to one or more
> > processes. There have been quite a few papers given at USENIX over the
> > years on this topic.
> 
> Have you been reading current-users? :-) There's been a thread about
> getting libpthreads into the kernel, and also one about CD-R support
> (which might mean some sort of real-time process a la Linux), in the
> last week. Also, there are a number of folks who have multi-headed
> boxes (i386's and I think a Sparc) who have posted before. There's
> definitely interest out there.

That would be really cool, to burn a CD while i work with the mac. :-)

Bye,
	Christoph 

Christoph Ewering         eweri@uni-paderborn.de
Husarenstrasse 48         Fon: 05254 12555
33104 Paderborn           www.uni-paderborn.de/Admin/eweri/