Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!nrl-cmf!cmcl2!brl-adm!brl-smoke!gwyn
From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.sys.apple
Subject: Re: Multitasking GS?
Message-ID: <8048@brl-smoke.ARPA>
Date: 9 Jun 88 01:11:25 GMT
References: <8Wf-=Jy00V4McuU0C4@andrew.cmu.edu>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 15

In article <8Wf-=Jy00V4McuU0C4@andrew.cmu.edu> jm7e+@andrew.cmu.edu (Jeremy G. Mereness) writes:
>It would take a lot of memory, but its possible, isn't it?

It isn't really practical to use the SOFTSWITCH technique with 16-bit
programs.  However, with the memory manager and loader that the GS has,
most of the basic hooks are present for reasonable multitasking.  The
hard part is getting tasks to relinquish the processor so that others
have a chance to run.  SOFTSWITCH relies on the control-panel interrupt
for manual context switching; a 16-bit version would leave all the
program memory in place and save just the display memory and a little
bit of stack.  The memory manager takes care of parceling out chunks
of memory so that several applications could in theory be coresident.
However, many of them are "poor memory citizens" and hog all available
memory when they start up, preculding any further program loading
until they terminate.