Path: utzoo!attcan!uunet!lll-winken!lll-tis!oodis01!uplherc!sp7040!obie!wsccs!dharvey
From: dharvey@wsccs.UUCP (David Harvey)
Newsgroups: comp.sys.amiga
Subject: Re: Amiga UNIX
Summary: Virtual Memory?  Go back to school!
Message-ID: <547@wsccs.UUCP>
Date: 27 May 88 06:00:44 GMT
References: <211@laic.UUCP> <3663@cbmvax.UUCP> <1872@sugar.UUCP> <134@ssdis.UUCP>
Lines: 28

In article <134@ssdis.UUCP>, gsarff@ssdis.UUCP (gary sarff) writes:
> In article <4928@sdcsvax.UCSD.EDU>, hutch@net1.ucsd.edu (Jim Hutchison) writes:
> What?
> The amiga does scatter loading of executable images into its free RAM.  this is
> not the same to me as virtual memory, and all the processes are in the SAME
> address space, (along with the OS itself).  Real virtual memory would

True.

> give each process ITS OWN address space starting at some point (zero say).
> "Each process sees a linear address space based at 0..." How does the process
> "see" this?  Chances are on a busy amiga, it won't even get loaded into the
> same place(s) in RAM two times in a row, if a program prints the address of
> some memory structure, it will probably be a different address.  In a virtual
> system it would always be the same, today, tomorrow, and next year.
> 
   Not always true!  The virtual address will remain the same, but the
actual physical location in memory doesn't stand a snowball's chance in
h... of ever being the same, especially if there are a lot of pages
being swapped in and out. 

   Admittedly, this doesn't negate the fact that an Amiga programmer
must assume much rf the oesponsibility that the OS should handle. But
what can you expect from a system that is fitting into such a tiny space
as AmigaDOS is in?  Be reasonable!

						dharvey @ wsccs

These aren't opinions, they are facts!