>>   And I'm quite very certain of this now:
>
> And even more so now.  In dec_3max_intr(), the interrupt bits are
> extracted and masked to get the active interrupt request.  They are
> then dispatched in two switch statements - which will work as long as
> there is only a single interrupt active in the group of interrupts in
> each switch arguement.  If two or more interrupts are active, the switch
> statement will fail, and the interrupt will not be processed.

The 'double switch' scheme is derived from what ULTRIX does.   I suspect
that it might be an issue of enclosing do {} while loop.

Tohru Nishimura