Re: O.K. So the abort pin isn't connected. Now...

[jpenne@ee.ualberta.ca (Jerry Penner)]

gdesroch@slate.mines.colorado.edu (DESROCHERS GARY FREDERIC) writes:

>    Then what actually happends when I access an address that does not
>exist.  Again this is on a IIgs.  I would like as in depth as you can give
>me.  Either that or any reference to IIgs documentation.

Nothing happens except the machine thinks it has accessed a correct
memory location.  You will get some funny number in a register if you
did a load.  Other than that you probably won't get any side effect.
Depending on your memory card, accessing "memory" that doesn't exist
may get you the value of some existing memory several pages lower.
That's the way it works with my GS Ram Plus if I access anything over
2.25 Megs, which is my machine's memory size.  Accessing locations
between $F0/0000 and $FD/FFFF gives you either the bank number or the
page number (check yours out with the monitor).

In any event, you will _never_ get a trap or interrupt from the
computer or its operating system.  The only abnormal thing that will
happen is you will either read garbage from the location or the
location will not be set to what you wrote there.
-- 
Jerry Penner   jpenne@ee.ualberta.ca   or   jjp@myrias.ab.ca