Re: GA144 article

From	rickman <gnuarm@gmail.com>
Newsgroups	comp.lang.forth
Subject	Re: GA144 article
Date	2012-07-24 14:49 -0700
Organization	http://groups.google.com
Message-ID	<f36c6ee2-bfce-49fa-a200-c30391401e80@googlegroups.com> (permalink)
References	<12aeb4bb-d890-4054-be00-c8c2b25b80dd@k5g2000vbf.googlegroups.com> <20bfe8cc-640d-4c88-8fa7-1ae05de11762@googlegroups.com> <7xhasxwjqj.fsf@ruckus.brouhaha.com>

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On Tuesday, July 24, 2012 6:12:36 AM UTC-4, Paul Rubin wrote:
> Daniel Kalny &lt;dkalny@seznam.cz&gt; writes:
> &gt; The GA144 allows for up to 256 arrayForth words for one node. This
> &gt; seems to me more than enough for a definition of a single Forth word.
> 
> Have you actually tried programming it and found 64 words to be enough
> to do anything interesting?  Node to node communication is quite a pain
> after all.  
> 
> The &quot;up to 256 Forth words&quot; is misleading, since the GA has 18-bit data
> words and 5-bit instructions, so a lot of the time you get just 3
> instructions per word.  Maybe even more annoyingly, any literal constant
> (like 1 or -1) takes up an entire word for the immediate data, and also
> often several instruction slots.  Writing contorted enough code lets you
> fill more of the slots than you could writing straightforwardly, but
> afterwards (at least for me) leaves me feeling dirty, rather than like
> I&#39;d achieved something interesting.

I view these things very differently.  I am used to FPGAs where the basic unit is a 16 bit memory used as a 4 input look up table (LUT) and a FF.  The F18 nodes do a lot better than that!  I think the first FPGA from Xilinx only had 64 CLBs which at that time were likely just one LUT and one FF although I don't recall, that was some 20 odd years ago.  And yes, you had to do all your own floor planning.  The experts in FPGAs all knew the details of how the routing connected.  Now no one cares as they just write HDL and the morass of software tools gives you something good enough given the huge amount of resources available.  I have seen products shipped using only 10% of a $1500 FPGA.  

I think the word analogy to be a poor one.  Rather than thinking of a node as a Forth word, think of it as a functional element where the function is software defined.  I have written a boxcar averaging filter in some 16 instructions which will likely take around 6 or 7 words in memory, I haven't put it through the tools yet.  Actually I may have to rewrite it.  It seems the F18 instruction set does not include a swap instruction which I didn't expect.  Sort of like the way nobody expects the Spanish Inquisition.  So I need to rethink my work on this.  

Rick

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GA144 article Mark Wills <markrobertwills@yahoo.co.uk> - 2012-07-18 03:48 -0700
  Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-19 10:51 -0700
    Re: GA144 article Mark Wills <markrobertwills@yahoo.co.uk> - 2012-07-20 01:30 -0700
      Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-20 01:48 -0700
        Re: GA144 article Mark Wills <markrobertwills@yahoo.co.uk> - 2012-07-20 03:25 -0700
        Re: GA144 article Syd Rumpo <usenet@neonica.co.uk> - 2012-07-20 11:59 +0100
      Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-22 18:59 -0700
        Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-22 19:16 -0700
          Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-22 19:31 -0700
            Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-22 20:08 -0700
              Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-23 16:24 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-23 22:33 -0700
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-24 14:04 -0700
            Re: GA144 article vandys@vsta.org - 2012-07-23 03:34 +0000
            Re: GA144 article Bernd Paysan <bernd.paysan@gmx.de> - 2012-07-23 14:11 +0200
              Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-23 16:47 -0700
              Re: GA144 article "Clyde W. Phillips Jr." <cwpjr02@gmail.com> - 2012-07-24 20:11 -0700
          Re: GA144 article Richard Owlett <rowlett@pcnetinc.com> - 2012-07-23 02:04 -0500
  Re: GA144 article Daniel Kalny <dkalny@seznam.cz> - 2012-07-24 02:37 -0700
    Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-24 03:12 -0700
      Re: GA144 article stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-24 10:36 +0000
        Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-24 10:28 -0700
          Re: GA144 article Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-24 22:12 +0000
      Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-24 14:49 -0700
        Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-26 13:25 -0700
          Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-27 13:17 -0700
            Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-27 14:31 -0700
              Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-27 22:02 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-28 23:03 -0700
                Re: GA144 article marko <marko@marko.marko> - 2012-07-30 09:12 +1000
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-31 01:09 -0700
                Re: GA144 article marko <marko@marko.marko> - 2012-08-01 00:19 +1000
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-31 09:59 -0700
                Re: GA144 article marko <marko@marko.marko> - 2012-08-01 10:13 +1000
                Re: GA144 article Bernd Paysan <bernd.paysan@gmx.de> - 2012-08-01 00:59 +0200
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-31 16:54 -0700
                Re: GA144 article Luca Saiu <positron@gnu.org> - 2012-08-04 10:46 +0200
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-08-05 11:04 -0700
                Re: GA144 article Luca Saiu <positron@gnu.org> - 2012-08-06 02:02 +0200
                Re: GA144 article Mark Wills <markrobertwills@yahoo.co.uk> - 2012-08-06 02:16 -0700
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-30 08:23 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-30 21:33 -0700
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-31 01:51 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-31 11:48 -0700
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-07-31 14:54 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-07-31 16:09 -0700
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-08-01 12:57 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-08-01 14:16 -0700
                Re: GA144 article vandys@vsta.org - 2012-08-01 22:32 +0000
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-08-01 16:03 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-08-01 16:13 -0700
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-08-01 16:10 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-08-01 22:18 -0700
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-08-02 11:47 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-08-02 14:32 -0700
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-08-02 16:01 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-08-02 16:38 -0700
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-08-03 08:40 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-08-03 09:19 -0700
                Re: GA144 article rickman <gnuarm@gmail.com> - 2012-08-03 11:15 -0700
                Re: GA144 article Paul Rubin <no.email@nospam.invalid> - 2012-08-05 15:50 -0700
                Re: GA144 article Mark Wills <markrobertwills@yahoo.co.uk> - 2012-08-06 02:21 -0700

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