intro.txt
8/11/95
Newt 3.1
(c) 1993, 1994, 1995, S. Weyer, All Rights Reserved Worldwide.
weyer@netaxs.com

- Introduction
- Newt in the News
- For Further Info
- Programming WARNING -- Newt and You
- NewtonScript
- Personal History, Credits
  

Read Newt.1st first.

Copyright S. Weyer 1993, 1994, 1995, All Rights Reserved Worldwide.

Newt is shareware. It may be freely distributed via online services and
bulletin boards if it is unmodified and includes the files described in
Newt.1st. It may not be commercially bundled or redistributed on CD-ROM,
floppy disk, PCMCIA, networks or other media without my permission. Please
continue reading for help, examples, warnings and other information.

=====
Introduction

Newt allows you to developing applications using NewtonScript, run and test
it, and save it as a packagte directly on your Newton.

NewtonScript (NS), Newton's built-in, object-oriented (o-o) language, shares
ancestry with dynamic o-o languages like Smalltalk, Self, Common Lisp, and
ObjectLogo. NewtonScript is the same language that is used by Apple's Newton
ToolKit (NTK). For more advanced users, familiarity with o-o concepts and
constructs would be useful; for others, Newt should serve as a brief
introduction to these ideas.  There is some information on NewtonScript
here, and more in the Newt manual (available to registered users).


Newt 1.0, the first version of Newt, was a turtle-graphics environment (this
is available now via an optional NewtDraw plug-in -- see turtle.txt).

Newt 2.0 introduced rudimentary capabilities to create dynamic views and
stand-alone applications that could later be run or transferred using RUNewt
[no longer needed]. Users interested in building applications could consider
Newt a portable prototyper, or as a learning step toward building more
complex, complete and industrial-strength applications via NTK on Macintosh
(and eventually Windows). See examples.txt for a list applications that can
be built in Newt (and that are available to registered users).  See Getting
Started in using.txt.

Newt 3.0 provides the ability to create real packages directly on the Newton
(this requires the NewtPack plug-in -- see packages.txt).


=====
Newt in the News

Newt 1.0 received an early positive review in the first issue of the (now
defunct) DoubleTap newsletter. "Building Native Newton Applications with
Newt" appeared in PIE Developers, Vol. 2.4, July 1994; pp.14-18.  Erica Sadun
reviewed Newt's turtle personality in the same issue. _protoReality 1.3 --
the NANUG newsletter, available as a Newton book -- features an interview
about Newt. _protoReality 1.3 & 1.4 have articles with my daughter on using
Newt to draw letters.  Serg Koren has posted a Newt 2.4 review (in Paperback
format) to newton.uiowa.edu/submissions, CIS, AOL and eWorld; it's available
on the World Wide Web via:
  http://www.netaxs.com/~archimag/revw.html
 
"Newt" is often used by the monosyllable-challenged to refer to a Newton.
"Newt is neat" could refer to the Newton itself and/or to this wonderful
application -- I will always mean the latter. Show Newt to your friends to
help achieve the worldwide goal of "Newt on every Newt"! So that Newt can
appeal to many families and orientations, it is gender "newtral" (in order to
reproduce more Newts, however, it has not been "newtered"); users should
probably not call themselves "newtists".

In other literary references, there is of course Shakespeare's famous drink
recipe: "eye of newt, ...". For crossword puzzle fans, "eft" is an old term
for "newt". Newts have hatched aboard the space shuttle Ñ "one small step for
a newt, a giant leap for newtkind". Tabloids will probably suggest a
connection between Newt and Elvis. This is likely, given Elvis' early career
as a "lounge lizard". However, the FBI has conspiratorially censored this
from the latest Newton ROMs [in early Newtons, you could set the Country
field of your Personal Preferences to Graceland, though this "Easter Egg"
could later interfere with dialing. A picture of a newt reappeared briefly
whenever you woke up your Newton. Other wakeup pictures can be obtained by
adding two or three spaces after your Address]. You should discount any
tabloid allegations suggesting any relation between Newt, football great
Knute Rockne, Newt, Wayne Newton, Olivia Newton-John, Newton Minnow, or last,
but not least, U.S. Speaker of the House Newt Gingrich.


=====
For Further Info

Since I provide little description of Newton syntax, other functions, or
curriculum ideas in this introductory file, I strongly recommend that you
stay reasonably close to the examples that I provide, register Newt to obtain
a more detailed manual and sample sources, wait for NS books to be published
(there is an introductory book by McKeehan&Rhodes for $30 with demo version
of Mac NTK), and/or buy the NTK and docs from APDA for $300. Take a look at
the NewATut and NewtTurT Newton books, which are interactive tutorials. PDA
(formerly PIE) Developers magazine is a source of practical programming
information and examples (cds@netcom.com).  Join the NANUG user group -- fun
and useful (marku@aix3.ema.com).

>> See newt-faq.txt for Frequently Asked Questions about Newt, NTK, etc.

>> See register.txt for Registration information/form

>> See examples.txt for Current List of 165+ Examples

>> See using.txt for information on installing and using Newt

>> See changes.txt for revision history and possible future features

>> See my home page for the latest info:  http://www.netaxs.com/~weyer

>> Contact weyer@netaxs.com if you have further questions


=====
Programming WARNING -- Newt and You

Exploring "mathematics microworlds" and doing problem solving by writing
programs are "powerful ideas" (Seymour Papert) and require some active
participation by you the learner -- taking risks and making mistakes. For
example, Newt allows you to execute arbitrary NewtonScript expressions. This
can be a formula for enlightenment or disaster. So, remember that this is
your Newton with your information and listen to your mother's advice about
backing up your system and hanging out with strange functions.

Using common sense in following examples and suggestions, and limiting
yourself to documented commands, you should reap many benefits and long hours
of enjoyment from using Newt. At the same time, "a little learning [about
programming] is a dangerous thing" (with apologies to Alexander Pope). I
would caution against experimenting with random functions or methods. "Gee, I
wonder what xxx does" might yield a simple error box, or it might zap a frame
or soup in your system.

At the same time, given the litigious nature of our society that yearns for
risk without responsibility, I feel compelled to add the following warning
(repeated in other variations several places later):

  >>> WARNING: USE THIS PACKAGE AT YOUR OWN RISK! <<<

=====

NewtonScript

Syntax
If you have already tried the examples and expressions outlined in under
Exploring Application or Turtle, looked at the examples applic0.nwt,
applic2.nwt and graphic0.nwt, then you should have a rough idea of what
NewtonScript (NS) syntax is like and several of Newt's commands. In NS,
programs or scripts are defined as "methods" on objects. Methods describe an
object's behavior or actions. Objects in NS are called "frames" (perhaps they
should have been called "newtrons"), which inherit attributes and behavior
from other frames, usually called "prototypes". Newt is a prototype or kind
of view. You tell Newt to do things by sending it a "message", e.g., go. This
message consists of a frame (Newt implicitly), a colon (:) separator, the
method name, and parentheses with zero or more parameters (values for
variables) separated by commas. For example, :go(50). A frame also has
"slots" (named attributes) that contain values that you can access, such as
times, dist, and deg. You can just use the slot name if it can be found via
inheritance, or frame.slot if you want to be more specific.

WARNING: IF YOU USE OTHER SYSTEM FRAMES, METHODS, AND FUNCTIONS BEYOND THE
ONES I HAVE DESCRIBED HERE, IN MANUAL, AND IN EXAMPLE FILES, YOU DO SO AT
YOUR OWN RISK.

For further information on NewtonScript syntax and view frame slots and
methods, NTK from APDA includes manuals, and other books will be published.
The Newt Manual provides a summary of syntax and built-in functions, along
with additional Newt methods for registered users.

Errors

In the unlikely event that an error occurs during Eval or Save, Newt pops up a
helpful error message and/or cryptic code. You can add another plug-in (ErrCnst)
that provides a complete list of error message. There is a Newton book
(newton.uiowa.edu/newton/software/books/error-book.hqx) that lists errors
from the NTK docs. If you have a Macintosh, the Newton LowDown DA
(newton.uiowa.edu/newton/software/hqx/misc/lowdown-da.hqx) may be useful.

Things to try: check your syntax against those in examples, check spelling for
method and variable names, missing or extra punctuation or values, garbage
from stray gestures, check number and type of arguments (e.g., float vs.
integer), and in general use your "newtle". If you think it is really a
problem with Newt, send me mail describing what you had entered, and I will
try to respond asap.

The 80+ page manual provides basic coverage of NewtonScript syntax and many
built-in functions. It also documents methods for creating applications,
customizing Newt, drawing with it, and accessing other system functionality.
Description and examples of specific system prototypes are provided in
separate files (see examples.txt).

=====
Personal History

I first implemented a screen turtle on an IMLAC display computer, accessed
from BBN Logo on a DEC PDP-10 at Stanford circa 1973. Subsequently, I
implemented other versions in Lisp, and used others in Smalltalk and
ObjectLogo. My long-time interests in children, learning and programming
environments, plus two small NTK examples, Dot2Dot and InspectorGadget, with
a little creative juxtaposition, started me down this path. Experience with
using and implementing object-oriented browsers and toolkits in Smalltalk and
Lisp and numerous user requests led to the Newt 2.x enhancements to support
application development. When I am not working on Newt at home or trying to
have a life, I am consulting, currently for pharmaceutical companies, on
"enabling technologies", in particular, pen-based systems.

Credits

Newt 3.1 was developed with NTK 1.5.1; some parts (plug-ins) of Newt were
developed with New itself. Newton and Newton ToolKit are trademarks of Apple
Computer. Kudos to Apple for creating an exciting product (Newton), and
powerful object-oriented language (NewtonScript) and development environment
(NTK). I look forward to new versions of NTK, documentation and examples. 
Manual created with FrameMaker 4.0 (from Frame Technology); electronic
version with Acrobat 2.0 (from Adobe), and various Newtonbook versions using
BookMaker.

My family contributed the evening and weekend time for me to explore this;
Ellie and Kristina helped with testing, Maria with proofreading. Finally,
thanks to the users and testers who have given me feedback and encouragement.
I hope that Newt can continue to evolve into an environment that meets your
needs.