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From: Chris.Gehlker@p12.f56.n114.z1.fidonet.org (Chris Gehlker)
Newsgroups: comp.sys.mac.programmer
Subject: RE: Using parameter blocks in ASM
Message-ID: <31733.2760E203@stjhmc.fidonet.org>
Date: 8 Dec 90 05:29:23 GMT
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> How does one set up a parameter block in assembly. I need a pointer to
> the block and then need to set up the contents. Where can it be? Must it
> be in the application heap or can it be in the system heap?

I just do a moveq  #paramblocksize,d0
            _NewPtr
            move.l  a0,a3; or wherever to save the pointer.
Then I can address the elements of the parameter block as offsets from a3. 
You can also put them on the stack with a subq #paramblocksize, sp or do a
link a6 #-paramblocksize and put them in a stack frame.  Some parameter
blocks need to stay around after you exit your routine, however, so the
latter methods are not safe in all cases.

I don't think applications should put parameter blocks in system heap
but drivers, inits ect. may.  Just use _NewPtr,Sys if you want them in
system heap.

 

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