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Re: [colorforth] Musings on SEAForth

Jeff Fox wrote:

Or gforth in windows.  And yes there is someone working on the site.
Thanks! I haven't even bothered with gForth on Windows -- SwiftForth is so much better. 


In 1988 Chuck said 16 bits wasn't enough for addressing enough
data to do something as large as VLSI CAD.  So he made the ShBoom
which was 32-bit.  In 1990 he said that 32 bits was overkill and
that 20 bits of address was enough for the CAD system and that
he could reduce all costs by 3/8 by going from 32 to 20 bits.
He designed MuP21, I21 and F21.  In 2000 he decided to make a
chip that could have a reverse pinout of an 18-bit fast cache
sram so that it could be mounted back to back with an 18-bit
fast ram.  RAMS came in 8, 16, and 18 bit sizes.  Having spent
a decade with 20/21 bit architecture he decided to try 18 bits
for the parallel design.  You can kind of think of it as an
18-bit slice if you want and you could think of the latest
chip as being a 720 bit wide chip

I think part of it is that Chuck rebels against the 8-bitness
you see in C.  He says C has to carry that burden but he
doesn't.
Ah ... yeah, if you can't get 24-bit RAMs then 18 it is, since it's better than 16 or 8. So is an 18-bit address wide enough for VLSI CAD? 


The ROM component in cores is for booting and for having routines
that can be called from RAM to reduce the size of programs in RAM.
ROM is much smaller and cheaper than RAM.
So is the ROM pre-set to something by default, or does each SEAForth customer have to have a custom ROM designed, tested and built? 


The closest thing you will see to *automatically* generating code
is taking parallel objects from a library and dropping in into
a design and having them placed, routed, instantiated, and
having their data flow mathematically verified for you.
That's pretty nifty if you can actually do it. I hope I can get a simulator in the near future and try some of this out. :) 


One can use parallel processors to do sequential things
efficiently if they can be programmed in pipelines and
you can also do other things in parallel very easily.
Yeah ... I wasn't in the room when the guys at FPS invented/discovered software pipelining, but I *was* in the building when they taught a Fortran compiler how to do it. :) 


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