Rhapsody memory,was Re: Memory on the Mac

[Adrian Hey]

On Sun 12 Apr, Michael Schuerig wrote:
> At 21:30 Uhr +0200 11.04.1998, you wrote:
> > Have I missed something here?
> 
> Yes, the most important thing: Brent was talking about the Rhapsody
> _Blue Box_. That is the Mac OS compatibility "box" running as a
> separate process on Rhapsody proper. I know very little about Rhapsody
> memory handling. About the only thing I know is that Rhapsody _is_ BSD
> Unix with OpenStep (Yellow Box) on top. Put differently I expect memory
> handling to be excellent.

I suspected this might be the case. The 'Blue Box' memory map Brent sent
us seemed so depressingly similar to the current Mac it _was_ hard to
believe that this was done for any reason other than to retain MacOS
compatibility. Clearly Brent hadn't anticipated that there would be at
least one dummy (me) who didn't already know that. Still, I think anyone
planning to use Clean in the 'Blue Box' (I take it this will be possible)
had better beware of virtual memory.

Also, I think most of my 'observations' about the disadvantages of
relying too much on the dubious benefits of virtual memory are just as
applicable to 'Yellow Box', or any other colour box.

Is UNIX memory handling excellent? I have never programmed for the UNIX
environment. But from my experiences of using UNIX apps on workstations
I can't say I'd noticed much excellence. They seemed pretty slow and clunky,
and they crashed a lot. But, perhaps I was using the wrong software on the
wrong platform running the wrong UNIX dialect. Buggy apps may crash, but
if they bring down the whole OS that does not indicate excellent memory
management to me. (Mind you, even my beloved RiscOS is far from perfect
in this respect.)

One thing still puzzles me though. If Rhapsody is really just UNIX with
knobs on, then there shouldn't be any great difficulty in porting Clean
to it. Most of the necessary compiler features (relevant CPU's supported)
and libraries for UNIX (Linux/Sun OS/Solaris) already seem to be there
(albeit still version 0.8). But, as usual, I'm probably overlooking
something. Perhaps the most of the libraries need re-writing due to
GUI differences.

So, I take it that if I ran half a dozen 'Yellow Box' apps at once I
wouldn't see any smoke coming from my hard disk after all. I think
now it's me who's guilty of wishful thinking, unless I bought _loads_
of RAM. Do you think 64Mb will suffice?

Btw, since writing my first message on this subject I have visited the
Apple website to see if I could get a better idea of how Rhapsody really
was going to manage memory (I.E. what was the underlying mechanism that
the 'Blue Box' used). But, alas, it was in vain. Even the 'developers'
pages seemed to be mostly marketing hype, so I gave up. I always get
cynical in response to marketing hype.

I think this will be my last communication on this subject (but that's
not a promise). Rhapsody memory management has very little relevance to
Clean at present. If it becomes relevant to Clean in the future it will
be too late for me gripe anyway, if I don't like it.

Regards
-- 
Adrian Hey