Re: [CAD_CAM_EDM_DRO] EMC? Jon ?

On Sunday 24 July 2005 07:35 am, caedave wrote:

> Thanks Alex, you saved me having to write all that.
>
> I shall be keeping mine (couple of projects in mind)
>
> Forth has lots of Port I/O Words (commands) and register shifts and rotates
> so writing the comms part of a program is easy. It also has full support
> to call other language compiled programs and routines.

If that stuff is in there, I must've missed it somehow...

I guess that's the point I was getting at, there. I don't recall any
indication of calling external code, but there's a complication I'd rather
avoid if at all possible because it means a whole other set of tools to deal
with.

> Just got to re-learn the Reverse Polish Notation methode again of doing
> the maths and learn all the new Windows (GUI) handling stuff that's been
> added since I last played.

Don't need any GUI stuff for this environment!

> Google search of "Forth" will through up a few sites with FREE downloads
> of the program (open source) and tutorials, and a yahoo groups search on
> the same has some groups, a couple of which are in the hundred plus
> membership.

Did the google thing a while, back, and what I got didn't seem to address
this particular point. I'll have a look at yahoo groups, though, dunno why
I didn't think of that. :-)

> Dave M.
>
> ----- Original Message -----
> From: "Alex Holden" <alex@...>
> Subject: Re: [CAD_CAM_EDM_DRO] EMC? Jon ?
>
> > On 23 Jul 2005, at 23:14, Roy J. Tellason wrote:
> >> (Never saw a Jupiter ACE, though. :-)
> >
> > They're pretty rare now; probably worth a few bob.
> >
> >> So I looked into it, and while there's a fair amount of programming
> >> capability in there, it was real difficult for me to see how this
> >> could be
> >> used in any sort of a control application. Maybe that was particular
> >> extensions that were written for it or something? In any case,
> >> I'd like to
> >> implement some stuff using it, but need to find more info, if any
> >> of you
> >> guys know of any.
> >
> > Forth's popularity is waning now (the UK Forth Interest Group
> > recently announced they will no longer be publishing a journal), but
> > there are still plenty of die-hards around who claim that Forth lets
> > them be several times as productive as C programmers. Forth has some
> > unusual features which make it well suited for low level control type
> > applications. The language, the development environment, and the OS
> > (typically with multitasking ability) are all part and parcel of a
> > traditional embedded Forth system. Despite this, the systems are
> > usually very small (much smaller than a comparable C based OS and
> > toolchain). Forth systems are traditionally interactive- you connect
> > a terminal up to them, write snippets of code, and immediately try
> > them out. The language is very extensible- in effect you write a
> > Forth program by inventing your own words (describing them using
> > sentences of simpler built-in words or words that you have already
> > invented yourself) and then eventually making a top-level sentence
> > out of your invented words. This interactivity and extensibility
> > encourages bottom-up development, which is great when the main
> > purpose of the program is to interface to hardware, as in most
> > embedded control systems. Forth is also usually pretty fast - not as
> > fast as C, but much faster than a BASIC interpreter, and the code it
> > produces is generally very compact indeed - much more compact than
> > compiled C code (part of this is due to the development philosophy
> > which encourages the use of lots of very short reusable words).
> >
> > The way I see it, Forth is a useful tool for low level stuff (eg.
> > interactively debugging a new piece of hardware), but it can be
> > difficult to understand other people's Forth code (especially if they
> > haven't bothered with comments), and high level stuff can get ugly,
> > especially all the manual data stack manipulation.
> >
> > There are also a couple of companies which sell expensive
> > professional Forth development systems for embedded systems which
> > include a flashy GUI and optimising compilers that produce code about
> > as fast as compiled C code. They're intended to compete directly with
> > the high-end C development systems.
> > http://www.forth.com/
> > http://www.mpeltd.demon.co.uk/
> >
> >> I think an outboard box with 8-bit parts running Forth might make
> >> one heck of
> >> a nifty addition to a CAM setup... :-D
> >
> > There's lots of ready-built Forth hardware around, including more
> > powerful stuff like tiny LPC2106 (60Mhz 32 bit ARM with 64K of RAM
> > and 128K of Flash) based boards:
> > http://www.mpeltd.demon.co.uk/tiniarm.htm
> >
> > --
> > ------------ Alex Holden - http://www.alexholden.net/ ------------
> > If it doesn't work, you're not hitting it with a big enough hammer