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From: ckp@grebyn.com (Checkpoint Technologies)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Amiga Resource tracking & Protection.
Message-ID: <19462@grebyn.com>
Date: 14 Mar 90 16:37:44 GMT
References: <208.25f3c82b@waikato.ac.nz> <1410044@hpcvca.CV.HP.COM> <19460@grebyn.com> <492e3b6e.1a5bf@moth.engin.umich.edu>
Reply-To: ckp@grebyn.UUCP (Checkpoint Technologies)
Organization: Grebyn Timesharing, Vienna, VA, USA
Lines: 39

In article <492e3b6e.1a5bf@moth.engin.umich.edu> chrisl@caen.engin.umich.edu (Chris Lang) writes:
>In article <19460@grebyn.com> ckp@grebyn.UUCP (Checkpoint Technologies) writes:
>>In article <1410044@hpcvca.CV.HP.COM> charles@hpcvca.CV.HP.COM (Charles Brown) writes:
>>	I prefer a dual-standard OS. Let it run unprotected programs (and
>>when they crash, the whole OS and computer crashes) and
>>protected programs concurrently.  Allow programs written for 'protected mode'
>>to be run on a machine without an MMU, and consequently without protection.
>
>What is the point of having memory protection if only SOME programs are
>protected?  I don't see how you can call them "protected" since they are
>NOT.  An unprotected program can crash a protected one?  Doesn't sound much
>like protection to me.

	Most Amiga's *can't* run protected programs.  No MMU.  Cost
$$$ for hardware (typically a 68030) to fix it, and most people won't.

	Most developers *won't* write programs specifically for a
68030 Amiga.  Bad business move; too few machines.

	(This'll be hashed for quite a while but I'm certain the
final conclusion will be:) You can't protect the existing Amiga software
base.  There is too much reliance on shared memory without any
formalism, and programs use direct access to IO features like the custom
chip registers and interrupts.  The only way is to write new programs to
use new protected-mode features.

	(My own conslusion) There's no possibility that a 68030-only
AmigaDOS protected environment will be successful. Hence my suggestion
of a new environment which developers can write programs for, and in
an MMU-equipped environment they'll be protected.

	A new protected environment that replaces the current
OS and only runs new protected-mode programs will fail and bring
the Amiga down with it.  This would eliminate the Amiga's software
base.  Booting one or the other environment would discourage people
from using one or the other, and you can bet the protected
environment would be the one to suffer.  Therefore I conclude that
this new protected environment must co-exist with the current
environment.