Subject: Re: PDP-11 thoughts
To: Johnny Billquist <bqt@Update.UU.SE>
From: Tom Ivar Helbekkmo <tih@kpnQwest.no>
List: port-vax
Date: 11/15/2000 10:59:38
Johnny Billquist <bqt@Update.UU.SE> writes:
> And speaking of Unix. I suddenly can't remember for sure, but I think that
> the networking stuff runs in supervisor mode.
That's what 2.11BSD does, yes.
> One might ask why the supervisor mode even exist. The only point
> really is that this allows you a fast way to change your mappings,
> since you don't need to reload the MMU registers, and each mode has
> it's own stack pointer.
...and I've always assumed that this is the reason.
-tih
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