From: Shawn Jefferson (shawnjefferson_at_24fightingchickens.com)
Date: 2003-09-16 01:30:08
On Tue, 16 Sep 2003 00:38:44 +0200, you wrote:
>
>On Mon, Sep 15, 2003 at 03:26:42PM -0700, Shawn Jefferson wrote:
>> How is the atari stack pointer (sp) calculated, I took a look in the
>> source and I can't really figure it out. Shouldn't it somehow be
>> calculating the end of RAM ?
>
>APPMHI is set to MEMTOP. The library constructors may decrease the value in
>APPMHI, if they need more memory. One of the last constructors is initsp,
>which initializes the stack from the value in APPMHI. So sp is set to MEMTOP
>minus "what is needed by the library".
Ok, so MEMTOP is set by the machine, which means that if I do this in
a configuration file:
RAM: start = $2E00, size = $7BFF, file = %O; # $7BFF: matches
upper bound $A7FF
and try to reserve the memory above A800 for some stuff, then the
stack is going to be right in the middle of that stuff ?
Should I be avoiding the memory used by the stack, or should the stack
be placed differently (at the end of the RAM from the config file?)
--
Shawn Jefferson
--
Shawn Jefferson
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