Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mandrill!gatech!bbn!rochester!cornell!blandy
From: blandy@marduk.cs.cornell.edu (Jim Blandy)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Suggestion for 1.4
Summary: Protected memory would be nice, but...
Message-ID: <18191@cornell.UUCP>
Date: 10 Jun 88 13:31:07 GMT
References: <8806021714.AA12190@jade.berkeley.edu> <611@myrias.UUCP>
Sender: nobody@cornell.UUCP
Reply-To: blandy@crnlcs (Jim Blandy)
Organization: Cornell Univ. CS Dept, Ithaca NY
Lines: 32

In article <611@myrias.UUCP> cg@suncg.UUCP (Chris Gray) writes:
>And now the blue sky: I've heard a weak rumor that 1.4 will be able to use the
>68851 MMU to provide protected address spaces. Any form of this, even if it's
>not the default, would be great.     [ stuff ]

Do we REALLY want protected address spaces?

It seems to me that a lot of the most interesting ideas out here
(ARexx, something about Message Brokers, etc) involve fiddling with
other people's address space.  It's one thing to insist that messages
and message ports be public; that's easy.  But everything a message
refers to needs to be public as well, so the receiver can access it.
And gee, libraries need to be public, and if a program patches itself
into library vectors then it would need to be public (assuming we
don't add lots of deprotection baggage to library calls), and...

I strongly agree that one haywire program shouldn't crash the system.
You should be able to crash as much as you like, in any way you like,
without disturbing other tasks (well, I don't LIKE crashing... :-).

But boy, do we get a lot of mileage out of our open address spaces..
While memory protection would be nice, it seems that a lot of the
power and simplicity of the Amiga would become restricted.  I'm not
talking about combatibility with old programs; I'm asking - do we want
to give up the advantages of an open address space?

Or is there a neat way to get around these problems (wouldn't that be
superb) that I'm missing?
--
Jim Blandy - blandy@crnlcs.bitnet
"insects were insects when man was just a burbling whatsit."  - archie
My opinions are my own, not Cornell's.