(I also need to give PNX a try one of these days, I
have a spare SA-4000
drive that I plan to use for this purpose when I get the nerve to swap
it out...)
I never really liked PNX. It's a personal thing, but for me the fun of
the PERQ is the fact that you can modify the microcode. There is of
course no hardware protection on the control store, and the mcirocode is
not zwitched on a process switch under PNX (or I assume any other OS,
there is no form of memory manager for the control store).
There;s little problem modifyiung the microcode on a single-tasking OS
like POS, but on a multi-staking one you've got to be darn cvareful
differnet processes don;'to change the same thigns in differnt ways. In
the end I decided I'd run unix on other machines and use the PERQ for
that which only it can do.
-tony