NetNews Usenet Archive 1992 #31/NN_1992_31.iso/spool/comp/sys/atari/8bit/5745

Text File | 1992-12-31 | 4.1 KB | 99 lines

Newsgroups: comp.sys.atari.8bit
Path: sparky!uunet!think.com!ames!nsisrv!nssdca.gsfc.nasa.gov!lanmaint
From: [e-mail] (Dave Yoest)
Subject: Re: FORTH-83 for Atari 8-bit; anyone interested?
Message-ID: <[e-mail]>
News-Software: VAX/VMS VNEWS 1.41
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Nntp-Posting-Host: nssdca.gsfc.nasa.gov
Organization: NASA - Goddard Space Flight Center
References: <[e-mail]> <[e-mail]> <[e-mail]>
Date: Thu, 31 Dec 1992 12:58:00 GMT
Lines: 85

In article <[e-mail]>, [e-mail] (Jeff McWilliams) writes...
>Pardon my ignorance toward Forth folks, but what was the language designed
>for, and what are the PROS and CONS for choosing FORTH over some other
>programming language?
>
>Jeff McWilliams
>


I haven't used Forth for many years, and this is an "off the top of my
head" answer, so I may be wrong.

As I recall, Forth was developed in the 70's by an astronomer. The
name Brodie keeps coming to mind, but that could be a book author.(I'll
look up the name if anyone really wants to know) From what I
understand, it was a SW tool he wrote to control the positioning of
large telescopes, and later got some use in the robotics disciplines.
It was very "bare bones", and you were supposed to write your own
routines for almost everything. In fact, every routine (called a
word in forth) became an extension of the language.

It was the main language I used on my 400/800's, I got the 800 back in
1982, and since I was never real fond of basic I got the VALforth
development kit. I heard rumors that VALForth was used internally by
atari as a game development language. Later A PD Forth calle FIG-Forth
was released and its core was as good as the Valpar Forth, but didn't
have all the neat pre-packaged routines for things like PM
graphics, strings ,trig,  and the like, so you had to write
your own. I kind of liked it because  Forth is an interpreted language
rather than compiled, so I could try out ideas without the
edit-assemble-debug-edit-assemble-debug cycles that were time
consuming with MAC65. (Remember, this is the early 80's before
Action!)

Then I switched to C , and did no SW development on my atari for the
last 5 years. Recently I started writing some small programs again (for
my kids), but I'm using LOGO instead of Forth. I just can't deal with
adjusting to Reverse Polish notation again.

Atari Logo is a very good implementation of LOGO, and I have free
versions of Xwindows Logo on my unix machine and there's a really
amazing free logo for MSwindows. Code portability from atari to
X-LOGO or MSWinLogo is very good. If you want to write simple programs
or teach your kids about computers, I highly recommend Logo.

Forth Pros:

  Its portable to other machines. Of course, you have to write good
  code in the first place if you want it to port easily. I ported most
  my stuff to the PC without a lot of work when I started using it as my
  work machine and made the ataris strictly fun machines.

  It's interpreted rather than compiled, so you get instant results.

Forth Cons:

  The biggest con was the reverse polish notation. I got used to it,
  but it wasn't natural. In my opinion, the expression 2 2 + . is not
  clear as " add 2 and 2 and print the result. Doing anything in basic
  then became a problem, because the command "20 LIST" in forth will
  list screen 20, and you get used to it working that way. Then you do
  something in basic, and want to see line 20, so you type "20 LIST" by
  habit. Then you get to remember what line 20 was supposed to be,
  and retype it.

  It's not as fast as Assembeler, and not that much easier to use than
  a good macro assembeler (once you get a few usefull macros in your
  library) For serious Atari 8-bit development, I think Action is
  probably a better choice, unless you plan to port to other machines
  that support Forth.




Dave Yoest
LAN Ops & Engineering Section Supervisor
NASA/Goddard Space Flight Center
Greenbelt, Md. USA  20646

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