Messages in this thread |  | | Date | Tue, 29 Aug 2000 07:33:22 -0500 (CDT) | From | Jesse Pollard <> | Subject | Re: SCO: "thread creation is about a thousand times faster than on |
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> > On Mon, Aug 28, 2000 at 06:52:18PM -0400, Alexander Viro wrote: > > > > > > On Sun, 27 Aug 2000 yodaiken@fsmlabs.com wrote: > > > > > Again, it's a possible, but pointless feature. You want fork/exec > > > in the presence of a file system and memory protection. But since > > > > Funny. I didn't know that -11/20 had memory protection... > > PDP-11 had good memory protection. I think PDP 8 may even have had it. > None of this newfangled paging b.s. though.
Yes and no. It depends on which system you had. If memory serves:
11/05 - no 11/10 - no 11/20 - optional (not usally provided) 11/30 - optional (depended on configuration) 11/35 - included (may have been optional) 11/40 - included (may have been optional) 11/45 - included (all versions higher than 45 included MM built in)
Then there are the LSI versions:
LSI 11 - no LSI 11/34 and higher - yes (11/34M equivalent - the M was memory management)
In the PDP-11/45 (the first version to have MM) memory management was an add-on capability and was available without.
Many of these systems were used in embeded configurations. The PDP-10 used an 11/20 as an IO/communications controller, and had an optional mm unit to be able to address the 18bit range of the PDP-10 (and DecSystem 10). It was optional because the PDP-10 didn't always have the memory that would demand it.
The 11/30 was used in some aircraft equipment.
The 11/40 was used where the embeded system needed floating point. I think that was in custom autopilots (not seen often).
------------------------------------------------------------------------- Jesse I Pollard, II Email: pollard@navo.hpc.mil
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