Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!cmcl2!adm!smoke!gwyn
From: gwyn@smoke.brl.mil (Doug Gwyn)
Newsgroups: comp.sys.apple2
Subject: Re: Back to the GS MMU hack
Keywords: multitasking, mmu, unix gs
Message-ID: <15243@smoke.brl.mil>
Date: 19 Feb 91 02:45:23 GMT
References: <27bef335.4e12@petunia.CalPoly.EDU> <1991Feb18.045719.22698@ux1.cso.uiuc.edu> <27c00f84.4155@petunia.CalPoly.EDU>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 10

In article <27c00f84.4155@petunia.CalPoly.EDU> rbannon@mira.acs.calpoly.edu (Roy Bannon) writes:
>What does VM have to do with pre-emptive multitasking?

Absolutely nothing, with the exception that it would introduce a new
cause for preemption: "segmentation violation trap".  However, that
is not needed for multitasking; it would have two main uses:  to
allow dynamic reallocation of stack and heap when a task expanded its
data requirements, and to catch programming errors that result in a
sufficiently wild misreferencing of memory locations.  Personally I
don't think these advantages would justify the cost of the hardware.