Getting Along (was: Re: Joe Kohn to moderate csa2 (was: METAL is now FREE!!!!!!)

[Jim Murphy <murph@apple.com>]

In article <C5pI5q.Eyr@news.iastate.edu> Ian Schmidt, irsman@iastate.edu
writes:
>Of course, Jawaid wants the GS to be a powerful multitasking computer,
and
>the Apple guys want it to be a powerful single-tasking computer.  Since
>neither side is likely to give, of course friction will result.  SI and
TM

     Wait a second. I was party to this discussion on GEnie, and neither
Matt or myself ever said we don't care for multitasking (in fact, I think
it's rather cool and plenty useful). What we did say, however, is that
attempting to redefine fundamental rules this late in the GS game just
won't work. For example, anyone can both load and store data in unlocked
blocks so long as they don't make any GS/OS or toobox calls and expect
the block to remain in the same location. This has been a fundamental
truth since the GS was released, and many, many programs rely on being
able to do this.

     However, this presents problems when you use a preemptive
multitasking system when you can be switched out when you may have been
accessing an unlocked block. There are quite a few solutions to the
problem, but the one that seems to be the simplest, "lock all blocks when
using them" won't work with 100% of the software that exists, because
they aren't being revised to comply with a redefinition of a fundamental
truth.

     From my perspective as GS system software engineer, we have to take
a rather conservative view on making changes in the way the GS
environment works. With a core base of applications that people rely on
daily, but aren't going to be updated, we can't do things that would
suddenly cause them to break. In fact, there are many instances in the
system software where we do things to make older applications even _more_
compatible (for such instances when they did illegal things, or relied on
certain non-guaranteed behaviour).

     So, _that's_ why I frequently argue that "you can't do that". :-)

(Sheesh, I wish csa2.programmer existed so we could have lots of
discussions like this. :-)

Jim Murphy          Apple II System Software Engineer         
murph@apple.com

"it's a perfect day for kiss and swell,	        - The Cure, "Doing the
Unstuck"
    for rip-zipping button-popping kiss and well..."