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Re: MISC-d Digest V97 #33


On Tue, 5 Aug 1997, Jeff Fox wrote:


> He also objects to programmers relying on the features of ANS
> Forth when they have "machine Forth" available.  Chuck felt
> that MuP21 had stacks that were big enough but he has more
> than tripled the size of the on chip stacks and insists that
> they are now big enough.  This is part of the reason why he
> prefers a BEGIN structure to a FOR NEXT or DO LOOP.   Not
> only may there be less computational overhead in the loop,
> but also fewer stack items are used.

There is one problem I see about using the machine stacks for everything,
and this is multitasking -- I'm very curious how does Chuck solve it.

If you allow yourself the freedom to multitask at any word boundary, You
are left with the fact that you have to spill the stacks to memory.  If
they are "big enough" for structured programs, they might be actually "too
big" to save and restore every time.

I agree that small hw stacks are great fro structured programming, anless
you multitask. 

Well, I know that Chuck says that people should use special purpose
coprocessors to multitask :-) 


--
Penio Penev <Penev@pisa.Rockefeller.edu> 1-212-327-7423