Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!hoptoad!tim
From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Re: Spleen venting (was: Re: 32-bit OS)
Message-ID: <8396@hoptoad.uucp>
Date: 27 Aug 89 01:22:50 GMT
References: <1456@draken.nada.kth.se> <10910003@hpislx.HP.COM>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Eclectic Software, San Francisco
Lines: 34

In article <10910003@hpislx.HP.COM> bayes@hpislx.HP.COM (Scott Bayes) writes:
>> Is this point so hard for you to understand -- that 16 bits is a low
>> limit which very many real programs will hit in the real world, while
>> 32 bits is a high limit which most real programs can treat as an
>> effective infinity?
>
>Except for file systems. It's only 2GB (4 GB unsigned), and bytes are
>a reasonable file system resolution level. My own OS will run up against
>the 32 bit boundary soon, what with big discs, magneto-optical discs, etc.

Yes, pretty soon we're going to be needing 64-bit file systems.  That
should last another decade or three.  (Then someone will figure out how
to do three dimensional optical storage crystals and even 64 bits may
not be enough.)  Current optical disks are already starting to push
against the 32-bit limit -- fortunately, a lot of it can be kept
internal to the OS.  A 4 gig limit on individual file sizes is livable,
it's only the overall file system that will need larger numbers.  (And
even then, with most real systems, blocks are represented not by a
single number, but by a pair of numbers in polar coordinates, so it may
be possible to live with pairs of 32 bit numbers for quite a while.)

>Tim is right: once the long boundary is hit, an application can't do
>diddly with a quad, unless we support it in the OS routines.

Yes, and I'm surprised that so many people have missed another of my
main points -- you *can* hack around 16-bit limitations, but you
shouldn't *have* to.  The more such hacks there are in a program, the
less elegant and so the less maintainable the program becomes.
-- 
Tim Maroney, Mac Software Consultant, sun!hoptoad!tim, tim@toad.com

"Our newest idol, the Superman, celebrating the death of godhead, may be
 younger than the hills; but he is as old as the shepherds."
    - Shaw, "On Diabolonian Ethics"