Re: OS For IIGS

[markem@flash.net (Mark Manning)]

Ok, earlier I ranted and raved on here.  I'm feeling much better now but
I'd like to submit an addendum to what I've already posted.

Some people will dispute with me that a W'95 machine and a Mac is doing
Multitasking.  Granted, the generic, broad scope meaning of Multitasking
is that a computer can perform more than one task at a time (or actually
to SEEM like it is doing more than one task at a time).  In order to do
true Multitasking you'd really have to have more than one processor going
at one time.

So let's discount the need for a multiprocessor system and just stick to
the part about can it handle switching between various processes.  Again,
in the most general sense of the wording - yes.  It can.  Where my pet
peeve comes into play is that this is not always true of the Mac or W'95
computers.  And here is why:

Both the Mac and W'95 computers make their programs be the masters and the
OS be the slave.  What I mean is: Is that both the Mac and W'95 programs
have to contain a small bit of code (on the Mac it is a single call
statement) which returns control of the computer to the system.  If this
isn't included in the program though, the Mac (and W'95 does this too)
will simply allow that one program to take over the entire computer.  This
is not true with Unix based OS's.  Under Unix, the OS is the master and
the programs are the slaves.  Which is how it should be.  If you want to
test this out it is very easy.  All you have to do is to create a very
small program which does nothing but loop.  Like this:

c:

main() {  while( 1 ); }

Basic:

5 goto 5

Fortran:

5 goto 5

(You get the idea.)

Now, there are a few conditionals to the above.  First, you can not use an
interpreted language.  This is because the interpreters have the code
built into them to allow control to pass back to the system.  Second, you
have to make sure that no additional code which handles calling the system
is included by accident (Code Warrior I think does this if you have the
proper options set).

Compile it.  Run it.  Once you do - you will not be able to get control of
your computer back.  At least, using Turbo C, PowerBasic, Microsoft C,
Microsoft Fortran, CodeWarrior, Think C v5.0, and FutureBasic I could
not.  However, on my Linux box - I could.  It took a while.  I grant you
that.  It took a while because that program was sucking up CPU usage like
crazy.  But Linux could still give me back control so I could kill the
program.

This (to me) _is_ the test of a true multitasking OS.  And if it can't
handle it - then the OS isn't really multitasking.  It's timesharing. 
Which (to me) is different.  That is to say: A true multitasking OS
multitasks ALL OF THE TIME.  No matter what's going on, no matter who's
doing what, no matter how many resources are being used; you still can run
all of your programs on that computer and have all of them doing
something.

Now granted, a lot of PR work has gone on with the various computer
companys.  Those marketing guys can make you think an IBM PC XT can do as
much as a Pentium 500mhz system.  But if the OS isn't always in control of
what is going on inside of that computer - it doesn't matter what some
sales person, marketing guy, or PR man is over there yelling at you.  It's
just not true.  No matter what they say.  No matter how they might want to
put it.  The system is still not multitasking.

Ok, now I will return to lurk mode and everyone can bang away at what I've
said.  Have fun!  :-)