Newt Turtle Info

The first version of Newt (Newt 1.0 in Oct 93) was a turtle-graphics environment. "Newton Turtle" and "NewtTurtle" seemed a bit too long, so I shortened its name to Newt, given its amphibious similarity to its Logo cousin and also its non-turtle uses. For exploration of Newt's "turtle personality", familiarity with Logo concepts and turtles would be useful though not necessary. Although Newt does not "understand" any of the Logo dialects directly, it does provide turtle commands, and an optional module for manipulating Logo-style data structures, i.e., words and sentences. Despite syntactic differences between NewtonScript and Logo, you can borrow ideas and translate code from Logo materials and books, e.g., Abelson & diSessa, books on fractals, etc.

Exploring Newt's Turtle Personality

First, install the NewtDraw plug-in, and then start Newt. See general user interface information.

Try the following (also see the NewtTurT interactive tutorial):

This quick tour should give you a basic idea of some of Newt's capabilities. Although there is a more information in this file describing Newt's interface, there is almost none regarding NewtonScript syntax or Newt's methods. If you would like real documentation and many more examples, register!

Newt Drawing

Newt's drawing area appears when you select it from overview, use Newt Controls, or evaluate an expression using drawing methods. You can use the following gestures to operate on the Newt closest to the start of the gesture (if you have multiple Newts).

Newt moves to location of pen using current Pen setting, preserving heading.
Newt sets heading to orientation (mod 45 degrees) of line. If Newt is already headed in that direction, it draws a line of same length (rounded to mod 10) of your gesture.
same as Erase
Hold down on a Newt until you "hear a squeak and get a fat pen" (actually the "hilite" gesture). Then, drag to a new location before lifting pen. Newt moves to new location without drawing.

Use the Save button in Eval Controls to save the current drawing in the Notepad under the current folder tab category. Newt currently "remembers" the current drawing when you close and re-enter Newt Drawing.

Newt Controls

Select this floating, draggable palette via overview. It is located initially at the top of Newt Drawing. and contains the following controls: Erase, Home, Pen, Color, Newt?, Times button & field, Dist button & field, Deg button & field. Like keyboards and Eval Controls, it can be dragged by its bottom border.

The value in this field (default: 0) can be used as a times variable in the Eval field. The Times button uses this value to create an iteration, e.g., if Times=4, Dist=40, Deg=90, tapping on Times tells Newt to :go(40) then :turn(90) 4 times, i.e., making a square -- the NewtonScript is written to the Eval field where it is executed immediately (and you can edit it later if you like). Tap Deg to turn, then tap Times or the Eval button again to see what happens.
The value in this field (default: 0) can be used as a dist variable in the Eval field. The Dist button uses this value for distance, e.g., if Dist=20, tapping on Dist tells Newt to :go(20), moving 20 in the "forward" direction, i.e., along Newt's current heading. This draws a line if Pen is non-zero. A negative value for dist just means go "backward". To give you some idea of scale, Newt's default drawing area on MessagePad is roughly 228x310 (on a MP100). Newt clips at its drawing boundary.
The value in this field (default: 0) can be used as a deg variable in the Eval field. The Deg button uses this value for degrees, e.g., if Deg=90, tapping on Deg tells Newt to :turn(90), turning right (clockwise) by 90 degrees. A negative value just means turn left. Newt will "mod" your number to prevent dizziness.
Newt erases drawing area, and remains with same position, heading and pen.
Newt teleports to center, sets heading to 0 ("up"), preserving pen setting but without drawing.
Newt sets pen thickness used in drawing (default: 1) and grows or shrinks in size. 0 means Newt just moves (no line)
Newt sets pen pattern used in drawing (default: black). Currently, this color is not available in saved Notepad drawings (everything is black).
If checked (default: yes), Newt appears with its tip at current x,y position, pointing in current direction, and "xor-ed" so that it does not interfere with drawing.
(for NOS 2.0 only): do you want to refresh the screen after every line? (more up to date, but slower)