Re: A89: Starting out assembly, need help
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Re: A89: Starting out assembly, need help
>
>In a message dated 11/30/98 4:06:13 PM Eastern Standard Time,
>TurboSoft@aol.com writes:
>
>> > have this effect: move.w #10,-(a0) will decrement a0 (the pointer) by
a
>> word
>> > and then move the word 10 into the new (a0).
>
>if it moves #10 into the new a0 AFTER it decrements a0, what's the point of
>decrementing it in the first place?
if you put a word into (a0-2), then it will fill the two bytes before a0.
This is what you want to do when you push something to the stack. since a7
points to the byte where the currently pushed object is, you want to have
the newly pushed object before that, and a new stack pointer pointing to the
new top of the stack.
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