Path: utzoo!attcan!uunet!portal!cup.portal.com!bcase
From: bcase@cup.portal.com (Brian bcase Case)
Newsgroups: comp.sys.mac
Subject: Re: Virtual memory init
Message-ID: <13871@cup.portal.com>
Date: 23 Jan 89 19:32:45 GMT
References: <1542@csuna.UUCP> <76000334@p.cs.uiuc.edu>
Organization: The Portal System (TM)
Lines: 26

>Furthermore, nobody believed that VM could be implemented so quickly
>on the macintosh, once there was a PMMU.  Well, Connectix has done the
>R & D necessary to solve the problem.  They should be applauded.  $295
>is cheap when you think of the risk they took.

[Hi Don!]

Right, and it still hasn't been done.  Connectix hasn't done real
virtual memory:  Mac applications must still be assigned and wired-down
to places in the 8 MByte memory space.  When they are paged out, they
can only be paged back into the same place.  The applications do not
see their own 8MByte partition, they must still share.  There is no
protection.

This might be virtual memory, but it certainly is not what is meant
when the term is used to describe the facility in other contexts.

Note, I am not knocking what they have done, rather I applaud it!  But
they have not done what will be done when the MacOS of the future allows
pre-emptive multitasking, private, large address spaces, protection,
interprocess communication, etc. etc. etc.  They have done a brilliant
thing!  But it is no substitute for the years of work needed.

As far as paying so much for so few bytes of software, the fewer the
better since the connectix software itself is also stealing from that
8 MByte "virtual" space....