trolfs@vax1.tcd.ie (Thomas Rolfs) (12/02/89)
W E L C O M E
T O
COMP.LANG.FORTH
The FORTH Programming Language Newsgroup
F O R E W O R D
-----------------
This is a monthly posting designed to introduce newcomers to
the comp.lang.forth group and to the FORTH community. Whether
you are a novice, intermediate or advanced Forther,
comp.lang.forth will give you the means to get in touch with
others who share your interests and needs, as well as
providing a forum for discussions and ideas on FORTH.
If you are totally new to FORTH and would like to find out
more about it, then you will find this posting especially
helpful.
Welcome to comp.lang.forth.
C O N T E N T S
-----------------
* Introduction To comp.lang.forth
* The History Of FORTH
* The FORTH Language - A brief description of FORTH
* Books On FORTH - Some recommended books on FORTH
* Getting FORTH For Your Computer
* On-Line Information Service (OLIS)
* Introduction to comp.lang.forth
---------------------------------
Needless to say, comp.lang.forth is a newsgroup which is
dedicated to discussions on the FORTH programming language.
These discussions cover:
+ Tips, hacks, and examples of programming
practises.
+ Ideas, proposals and problems for contemplation.
+ Using FORTH for common/special/bizarre
applications.
+ What the future holds for FORTH, ie Standards,
usage, new fields/applications etc..
+ Whole ranges of computer science topics, eg expert
systems, object oriented programming, interfaces
etc..
+ Hardware applications, FORTH chips, computer
architecture.
+ Anything else that's interesting.
Also found are:
+ Requests for help, information etc...
+ Light relief (:-)
+ News about happenings in the FORTH community
The amount of traffic which goes through the group is quite
low, but the quality of articles is very high. Of course,
this shouldn't deter new people from adding their input. Far
from it. One of the nicest things about the group is the
encouragement and support that newcomers to FORTH and the
FORTH community get (and I'm speaking from experience). So,
put finger to keyboard and let us know what you're up to or
if you have any questions about FORTH.
* The History Of FORTH
-------------------------
This is an extract from the F-PC User's Manual.
....
Forth was invented by Charles Moore in the 1960's as he
developed specialized tools for various applications. It was
formalized into a programming language for telescope
automation while Mr. Moore was with the National Radio
Astronomy Observatory. As this work was supported by public
funds, Forth was born as a public domain software package
which followed telescopes to many different countries. In
1972 Mr. Moore left NRAO to form FORTH, Inc. in order to
market Forth systems and services. Implementations developed
in FORTH, Inc. were proprietary and their usage required
license from FORTH, Inc. However, a copy of Forth for PDP-11
was released to DECUS, the DEC Users Group, which became the
only readily available public domain Forth for many years.
Forth Interest Group was organized in 1978 to encourage the
use of Forth on small personal computers, which gradually
became available for individual users. One major effort by
Forth Interest Group was the formation of Forth
Implementation Team lead by Bill Ragsdale to build figForth
and put it in the public domain for general distribution.
Because figForth was implemented on many microprocessors
based on a single model and released with complete source
listings, it became the de facto standard of Forth on
personal computers, eclipsing polyForth which was by then the
main product from FORTH, Inc......
The other major objective of Forth Interest Group was to
establish a standard definition of Forth as a programming
language. Forth Standards Team was organized in 1978. It
took the Forth-77 Standard developed by Forth users in Europe
and produced Forth-78 Standard. It was very unsatisfactory
and was almost immediately reworked into the Forth-79
Standard which was accepted by Forth Interest Group for
promotion. However, Forth Interest Group also decided that it
would not publish implementations and only encouraged Forth
vendors to provided implementations and support. The only
major public domain Forth supporting Forth-79 Standard was
MVP-Forth written by Glenn Haydon and distributed by Mountain
View Press.
Forth Standard Team continued the refinement of Forth
language and published the Forth-83 Standard in 1983. Again,
Forth Interest Group supported and promoted it, but did not
provided any implementation. Henry Laxen and Mike Perry felt
that the Standard could not spread without a faithful and
useful implementation. They implemented a comprehensive
model on 8080, 8086, and 68000 processors with fairly uniform
and transparent interfaces to the CP/M and MS-DOS operating
systems. This public domain F83 model found wide acceptance,
especially among IBM PC users after it was listed in the PC-
SIG catalog. ......
Dr. C. H. Ting
Documentation Coordinator
F-PC Working Group
* The FORTH Language - A brief description of FORTH (*)
---------------------------------------------------
If you have never seen or used FORTH before, then this
section will give you an ideal of what FORTH is like. It is
not intended as a complete introduction to FORTH, but simple
to give you a taster of what to expect. There are a lot of
very good books and articles which introduce and explain
FORTH much better than I can ever hope to.
**WARNING**
Before we go on, I feel it is my duty to warn you that the
following text, and possible consequences there after, may
lead the unsuspecting reader to become what is commonly
refered to as a "FORTH USER". If you do develop the urge,
don't panic. There are organizations available to give
support. This warning was sponsored by the "SAY NO TO FORTH"
Counsel. Remember: You have been warned ...
***********
OK. Now read on :-)
FORTH consists of basically 3 things:
1) a DICTIONARY
2) an INTERPRETER/COMPILER
and
3) a DATA STACK (holds integers): Also known as the
: PARAMETER STACK
The DICTIONARY is a collection of FORTH WORDS. WORDS are
equivalent to FUNCTIONS in C and are called (executed) just
by typing their name. New WORDS are created using existing
ones and are compiled one at a time. Therefore, once a new
WORD is compiled, it immediately becomes part of the language
and it itself can be used to describe new WORDS. This gives
very fast turn around times, due to the incremental
compilation, and makes FORTH an extendable language which you
can tailor to you specific needs [To get a better idea of the
philosophy behind FORTH, ie. the use of WORDS, read "Thinking
Forth" by Leo Brodie].
The DATA STACK is usually used for parameter passing between
WORDS. For example, in FORTH there is a WORD called "+"
(plus) which works by popping off the top two items from the
DATA STACK, adding them and pushing back on the result. An
example is given further on.
The INTERPRETER/COMPILER is itself a FORTH WORD called
INTERPRET. Put simply (ie. ignoring compilation), INTERPRET
checks for two things; numbers and names of WORDS. Numbers
are pushed on to the DATA STACK and WORDS, whos names have
been typed, are executed.
For example, if we want to add two integers and show the
result then we would type in the following:
123 56 + . <RETURN> 179 Ok
FORTH interprets from left to right, so that 123 and 56 are
first pushed on to the PARAMETER STACK. Then the WORD "+" is
executed. And Finally, the WORD "." (period) is executed.
["." (period) prints out the top item on the STACK]
This is a very simple example, just to give an idea of what
FORTH is like. There is *MUCH* more to FORTH than can be
covered here and some suggested reading material is given in
the next section. FORTH is well worth a look at, just for its
uniqueness alone.
(*) The description given here is very simplified and
brief. Hopefully, I will have a more complete and in
depth introduction to FORTH available from OLIS.
* Books On FORTH - Some recommended books on FORTH (+)
--------------------------------------------------
Recommended book for casual reading:
- "Thinking Forth,
a language and philosophy for solving problems"
By Leo Brodie.
Some books for reference:
- "Threaded Interpretive Languages"
By R. G. Loelinger.
- "F83 Source"
By H. Laxen & M. Perry.
Some Books for FORTH tuition (*):
- "Starting Forth", (2nd Ed.)
By Leo Brodie.
- "Mastering Forth" (2nd Ed.)
By Martin Tracy & Anita Anderson.
- "FORTH: A text and reference"
By M. G. Kelly & N. Spies.
(*) FORTH is best learnt if you have FORTH running on your
computer, while you read.
(+) Request the BOOKS_FORTH file from OLIS for a more
comprehensive listing of books on FORTH. See the Section
on OLIS.
* Getting FORTH For Your Computer
---------------------------------
Important thing to remember when getting FORTH for your
computer is that there are different DIALECTS of FORTH. The
important ones to remember are:
FigForth
Forth-79 Standard
Forth-83 Standard
Most texts on Forth will usually refer to these dialects when
giving examples of code, so if you are trying Forth for the
first time, make sure that you get a Forth implementation
that supports to one of the above. Some common ones are:
o F83 by Laxen & Perry - a PD Forth-83 standard Forth
o MVP-FORTH by Glen Haydon - a PD Forth-79 standard Forth
o FPC by Tom Zimmer - a PD Forth-83 standard Forth
At the moment I'm trying to get together info on good PD and
commercially available Forths for most makes of computers.
Until then, just ask comp.lang.forth for any help on getting
Forth for your particular machine.
* On Line Information Service
-----------------------------
****** O L I S ******
On Line Information Service
FORTH is not the an easy language to learn. Of all the
languages going it has to be, initially, one of the
hardest. It's a language which needs to be understood well
before real gains can be made from it. This understanding can
be very hard to achieve if you don't have a good
comprehensive knowledge base to draw from. The idea behind
OLIS is to provide this 'knowledge base' in order to help
novice and intermediate Forthers.
OLIS is a home grown mail server which resides in my account
at "TROLFS@vax1.tcd.ie" (192.35.207.59). Through OLIS, files,
containing information on different aspects of FORTH, can be
requested. Hopefully, these files will provide an easy no-
hassel way to find out more about FORTH.
OLIS is very new and limited in resources. There are few
files at the moment, but over time they will increase as I
take articles from here and there (mainly from
comp.lang.forth). However, I hope that the main bulk of
OLIS's 'knowledge' will come from people on the net, in the
form of small snippets of information.
To find out more about OLIS, just send mail to
"TROLFS@vax1.tcd.ie" with the subject line "OLIS:REQUEST" and
put the word "HELP" somewhere in the body of the message.
If you have any queries or comments, then just mail me at the
same address. - Tommy (OLIS Developer/Janitor)
DISCLAIMER: OLIS is in no way connected with Trinity College
Dublin. OLIS is run from my own account, on my
own time. TCD have no obligation to support OLIS
and can have OLIS discontinued at any time they
feel necessary.
--
Thomas Rolfs mail: 33 Beechwood Lawn, Dun Laoghaire, Eire. //
E-mail:TROLFS[Thomas Rolfs On-Line Forth Server - "OLIS"]@vax1.tcd.ie \\//+IV
-----------------------------------------------------------------------\X----
I want to live forever or die in the attempt
-- Unknown