Re: [MiNT] Supexec taking one VBL?

[Petr Stehlík <pstehlik@sophics.cz>]

Thomas Reiss píše v Út 09. 09. 2008 v 19:21 +0200:
> The Amiga OS never had any memory protection and will never have mainly
> because of the message passing stuff - I can't get into more details,
> sorry. The MMU is however used by some debugging tools to detect
> unexpected memory accesses, etc.
> Of course, without any protection, you can access anything and trash
> everything you want but the OS provides such nice stuff as described by
> Miro that prevents you from banging the hardware.

The Amiga OS most probably does not *prevent* it (if I understand your
explanation above correctly) but makes it *unnecessary* and the Amiga
programmers are so smart/lazy/disciplined that are not trying to work
with the hardware directly.

That's actually the purpose of a good operating system - to separate
applications from underlying hardware by providing functions that do
what's necessary. Unfortunately TOS does offer just a few XBIOS
functions and those are either slow or buggy so programmers tend to skip
them and try to drive the hardware directly. 

It's obvious that if an OS like FreeMiNT wants to prevent applications
from messing with hardware it must first offer an API that will cover
everything (demo/game) programmers usually need. When this becomes part
of FreeMiNT then programmers might start using it and slowly start
rewriting old and creating new games and demos for FreeMiNT.

Another obvious thing (if we want to stay in this sci-fi land for
another paragraph) is that the API must be accessible in other major
systems used on our hardware (TOS, MagiC) so there should probably be a
library that the game/demo programmers ("coders" :) could link or
distribute with their 'products'.

Well, I'd suggest to check the libSDL (www.libsdl.org) - maybe it's
close to what they need. If not then I am afraid it's about 22 years
late for inventing a better XBIOS...

Petr