Newton Toolkit tips and tricks

This page provides tips for using Newton Toolkit as well as information about undocumented bugs and other details.



NTK officially requires a Macintosh with at least a 25 MHz 68030 processor and 8 MB of RAM. I do not know whether it will run with anything less. It also runs fine with Classic on Mac OS X, but see the Newton FAQ for details.


NTK requires Windows 95 or newer. It can also run on Windows 3.x if Win32s is installed.

NTK seems to not run on 64-bit Windows versions (it closes right after starting up), but runs fine on 32-bit Windows XP and Windows Vista. The only problem is that downloading packages causes errors for packages larger than about 5 kilobytes. This can be worked around by using another package downloader, such as Newton Press, but it makes debugging harder because then you have to frequently connect and disconnect the Inspector.

For serious Newton OS development, I recommend using Windows 98 in a virtual machine, or a Macintosh emulator.

ReactOS, as of version 0.3.17, seems to run NTK just fine.



Probably the easiest way is to download the NewtonDev archive. It contains the last version of NTK (1.6.4), as well as the Newton C++ Tools, documentation, and more. Warning: the GlobalData file in that distribution is quite bloated; see below.


You can get NTK from UNNA (version 1.6.1 is the last for Windows). There is also example code for it.

Using NTK's NewtonScript interpreter

NTK is not just a NewtonScript compiler. It is an interpreter as well. However, this functionality is not exposed by default.


See the NTK manual on page 5-29 for information on the GlobalData file. Personally, I use {key: 36, control: true} (Ctrl-Enter); {key: $e, command: true} (Command-E) is also a good choice.


Create a file called GlblData.f in the folder where you installed NTK and paste the following code into it:

protoEditor:DefineKey({key: 0x6B /* numpad + */}, 'EvaluateSelection);

Restart NTK and you will now be able to execute NewtonScript code by selecting it and pressing the + key on the numeric keypad. The output will appear in the Inspector window.

(Source: Bob Ebert in comp.sys.newton.programmer)

This works because NTK compiles and executes the contents of that file each time it starts. You can also, for example, set printDepth to 0 to get nice compact listings of arrays and frames:

printDepth := 0;

You can also of course define functions inside it (either using DefGlobalFn or assigning them somewhere else), for example:

vars.LoadTextFile := func(Filename)
	// Takes a filename of an ASCII text file and returns a string with its contents.
	// Windows-only because Macintosh NTK doesn't have LoadDataFile.

	local ASCII := LoadDataFile(Filename, nil);
	local Len := Length(ASCII);
	local String := MakeBinary(Len * 2 + 2 /* NUL terminator */, 'string);

	for i := 0 to Len - 1 do
		String[i] := ExtractChar(ASCII, i);

	return String;

You can also execute NewtonScript code directly from a file at any time with the global function Load.

See the C code produced when compiling a native function

Native functions are actually first translated to C and then compiled to machine code. Walter Smith explains this in comp.sys.newton.programmer.

NewtonScript grammar

At least the Windows version of NTK contains a NewtonScript grammar (starting around offset 2210A8h) which is mostly identical to the one in The NewtonScript Programming Language.


Access to an array through a path expression

Example: [1, 2, 3].(-1)

NTK checks whether the index is too high (and returns nil if it is), but not whether it is too low. It is possible to crash NTK with this.

This happens in both Macintosh and Windows versions. The Newton OS behaves correctly in this case and returns nil.

Assignment to an array through a path expression

This should throw an exception, but doesn't:

A := {B: []};
A.B.(0) := 1;
<Binary, class [2: NIL, b], length -12>


It is possible to crash NTK by calling the global function RemoveSlot if the first parameter is a frame and the second parameter is not a symbol.

This bug seems to be only in the Windows version. In the Macintosh version, it does nothing. In Newton OS, it throws an exception.

First published on .
Last updated on .

Table of contents

Contact me