In article <5.2.0.9.2.20030305125134.00b667a0@mail.b.astral.ro> you write:
>A couple of years ago I have read on your site that the Apple architecture 
>(the Mac) has a major design flaw regarding the measuring of time, flaw 
>which shows up only in xxxBSD, and not under the Classic MacOS (I can not 
>find that article any more).

<http://www.netbsd.org/Ports/mac68k/faq/faq-3.html#ss3.17>

>Can you tell me more about that ? Was there any action from Apple regarding 
>this fault ? Did they correct it starting with some model ?

My understanding is that the problem affected most 68K Macs, and that it was
caused by the clock interrupt having the lowest priority rather than (as
would be usual) the highest.  Some Quadras had a fix for this problem which
allowed the OS to switch the interrupt routing to "Unix mode" (intended for
A/UX) in which the interrupts were in a sensible order.

I don't believe this has ever affected Power Macs, since their interrupt
priorities are handled entirely in software and can thus be set sensibly
from the start.

-- 
Ben Harris                                                   <bjh21@netbsd.org>
Portmaster, NetBSD/acorn26           <URL:http://www.netbsd.org/Ports/acorn26/>