Re: Color Forth hardware stacks

[wmor1@xxxxxxxxxxxxxxxxxxxxx]

> From:          Christophe Lavarenne <Christophe.Lavarenne@inria.fr>
> On Tue, 5 Aug 1997, Penio Penev wrote:
> 
> > 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.
> 
> This induction is right, but it has two possible conclusions:
> - either "have your stacks in memory",
> - or "don't allow yourself the freedom to multitask at any word boundary".

One of the good features of Forth procesoors is that stacks can be 
kept out of memory and speed up execution (as main memory is more 
devoted to instructions).   On a side issue  this brings up another question if we 
have non changable code seperate for data memory why not seperate 
them as well, so that the main buss is freed more ( but probablt only 
a slight increase because of sequence).  I think that Chucks idea in 
the SH-Boom, of caching the caches to memory) was good.  So the 
required miminuim depth for normal stack operations is kept on chip 
and extra stack space is cached out (also used in the SC32 from 
Silicon Composers), 
with a limited number of high speed task with their own onchip stack 
space, slow non-critical tasks can go directly from memory.  This is 
the sort of stratergy I have looked at in instruction set 
stratergies, and now we are getting the technology to afford the 
space to do it (on a big enough chip die).  To sum up large stack 
area on chip devided between tasks with overflow requirements being 
cached to memory.

About colour Forth, nice idea but as Andrew Houghton pionts out, a bit 
useless for colour blind people.   Another topic is that while good 
for clarifying syntax, how are we supposed to print it on a b&w 
printer?

Wayne.

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Wayne Morellini  <wmor1@student.monash.edu.au>

Post Graduate Student Representative.
Rusden Campus, Deakin University, Vic, Australia.

GradDip Media Studies (Current), Bach InfoTech (Distinction)
& AD Business(Computing).
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