I have seen the other topics on Java for Nspire, and they all seem to be dead. So I will create a new one to keep the idea alive 

I hope the following will encourage greater interest in the idea of Java for the Nspire, and possibly lead to this idea becoming a reality. I have had some experience using Java ME for Lego robotics, and I am somewhat surprised that something similar is not available for the Nspire yet. The Nspire is the first TI calculator that can support a JVM with reasonable resources to spare, so why not?


Can the Nspire handle it?

A JVM (Java Virtual Machine) implementation called Lejos has been available for the Lego Mindstorms NXT robotic brick for years already: http://lejos.sourceforge.net/. I will use the Lego NXT as a basis for comparison with the Nspire.

The NXT's specs compared to the original Nspire non-CAS:

	NXT	Nspire
Processor:	ARM7 @ 48MHz	ARM9 eq. @ ~150MHz
RAM:	64kB	16MB
Flash ROM:	256kB	20MB

The Lejos project chose to implement Java ME instead of SE for obvious reasons. Java ME is probably the most we can hope for.

Minimum system requirements for Java ME:

RAM:	8MB
ROM:	5MB

(from http://www.oracle.com/technetwork/java/embedded/resources/me-embeddocs/index.html)

Note that these specs are for Linux. The Nspire's simpler OS should leave even more room to spare. Can the Nspire handle Java ME? I think so.


Is it practical on a time/effort basis?

Sure. The Lejos team did it for a much more limited platform, and did it well. Their implementation has garbage collection, threading, exception handling, synchronization, and many of the other features expected out of Java. Much of the core Lejos JVM and classloader can be reused for the Nspire. The LCD and input classes can be customized for the Nspire's hardware. (Color support on the CX)


Why Java? Isn't Lua enough?

Java's performance will definitely be better, possibly much better:

• Lua is dynamically typed, while Java is statically typed
• Lua programs must be parsed into tokens/bytecode before execution, Java programs are precompiled into bytecode ready for execution
• Nspire Lua interpreter was written by TI (automatic performance hit! )

Even without Jazelle or JIT, Java should be fast enough for most purposes.

Lua is more of a scripting language, while Java is more of an application language. Lua is easier for beginners to pick up, while Java is a more efficient language for experienced programmers. Plus, more people should be familiar with Java, since it is more likely to be taught in CS courses and has a more C-like syntax.


There will be no shortage of Java programs that can be ported to the Nspire (excluding you-know-what ). Thousands of MIDlets, or mobile phone apps, can be easily ported. With a suitable compatibility layer, we should even be able to run some applets. Java for the Nspire would unlock massive potential.

Why Java? Isn't Lua enough?

Java's performance will definitely be better, possibly much better:

• Lua is dynamically typed, while Java is statically typed
• Lua programs must be parsed into tokens/bytecode before execution, Java programs are precompiled into bytecode ready for execution
• Nspire Lua interpreter was written by TI (automatic performance hit! )

There is already C and assembly support on Nspires through Ndless, and those programs are precompiled and not written by TI. But I am sure you already know it since you are probably not going to write your JVM in Lua nor in Basic but probably in C or ASM

Anyway, that seems to me a good idea. SDL was ported to the Nspire series and now I hear people saying "you can use nSDL for your program". Maybe your project will bring some "you can use nJVM for your program", who knows ? That would bring some activity out there for sure since not everybody knows C and some people prefer Java

and I am somewhat surprised that something similar is not available for the Nspire yet.

It's not surprising at all: the fact is that hardly anybody cares about the Nspire

But your idea could bring more activity, so it should be pursued

YES! YES! DO IT!
In learning java next month, and that would be awesome if I could use it in the nspire too!

It's the standard lua, just without io and system libs, and some extra libs by them

IOW, it's significantly two-way incompatible with Lua on pretty much other platform.

But yeah, porting some Java framework + library ought to be possible on the Nspire, and unlock some potential (at least once in a while, when native code development is available to users).

IOW, it's significantly two-way incompatible with Lua on pretty much other platform.

While true, it not really significant because basically every Lua platform is different .. just take a look at Love2D, Corona, implementations of Lua in games ..
None of those are compatible with each other, none. Also, the TI-Nspire API is pretty close to the one of Love2D (both event based, similar working structure) so porting stuff between those two platforms isn't that hard.

Anyway, I'm going too much of topic here. Sorry for that ^^

They die out fast because poeple just dont have enough time to work on it.
I do have to admit that having java would be nice...
also, nice necro

Qwerty's post actually gives a pretty good explanation.

I'd also add:
Although java would be nice, there are other good options available (C, ARM ASM, Lua). This being the case, java is not seen as a necessity.

Any implementation of Java would require ndless, and TI is constantly updating their OSes. Each update seems to block ndless. This is somewhat discouraging to prospective programmers. The mentality is "Why invest your time if it will all be for nothing?" C and ARM assembly (which also require ndless) already struggle with popularity, I fear Java would be the same.

Time. Such an undertaking is a big commitment, for a few individuals it would be a large undertaking. I think if this were to be pursed, a decently sized team would be a must.

Also, the necro is fine, as it is relevant to the topic. No need to start another thread.