Robots w/Lasers » Java http://blog.davr.org Nintendo DS & GBA development, microcontrollers, and occasionally FPGAs Thu, 08 Jul 2010 17:22:28 +0000 en hourly 1 http://wordpress.org/?v=3.0 Partial MIDP support on the DS http://blog.davr.org/2008/06/09/partial-midp-support-on-the-ds/ http://blog.davr.org/2008/06/09/partial-midp-support-on-the-ds/#comments Mon, 09 Jun 2008 17:41:54 +0000 davr http://blog.davr.org/?p=78 ole has taken my KVM port to Nintendo DS and added some updates. I haven’t played with it much, but he lists the changes as follows.

R3: New features added by Ole:

  • fixed the CLDC implementation (timer, memory size, system properties)
  • added support for reading of the PNG images (code taken from the PhoneMe project)
  • implemented native functions for rendering the basic graphics primitives on the screen
    (lines, rectangles, triangles, images)
  • added support for accepting the JAD files in the application browser
  • added the core part of the Pstros MIDP library
  • added VideoTest example to show how to draw on the screen
  • added ‘_rebuild.bat’ to show how to build and preverify the class files.
    Note WTK installation is required.

This is quite interesting if it is able to run some MIDP-compliant games, but we’ll need to do some testing to see how the speed compares to your average mobile phone.

UPDATE: He’s made a few more updates since I originally made this post. Be sure to check out ole’s site for the latest info and download links.

]]> http://blog.davr.org/2008/06/09/partial-midp-support-on-the-ds/feed/ 5 Java for NDS? http://blog.davr.org/2007/08/08/java-for-nds/ http://blog.davr.org/2007/08/08/java-for-nds/#comments Wed, 08 Aug 2007 16:36:36 +0000 davr http://blog.davr.org/2007/08/08/java-for-nds/ I know what you’re thinking…”That’s a horrible idea and you’re a horrible person for suggesting it!”

The main problems with Java on DS:
1. Interpreted languages are slower, the overhead is bad on a slower embedded platform
2. No direct memory access. Almost all of the DS hardware is interfaced by reading and writing directly to specific memory locations
3. No primitive unsigned 8-bit types. What were they thinking?

But…I went ahead and did it anyway, just for fun. I didn’t start from scratch, I took Torlus’s KVM port to GBA and used that as a base for getting it to work on DS. Right now, when it starts, you pick a .class file, and it will run it! In addition, using KNI, I’ve written a basic wrapper around parts of libnds, enough to read input from the touchscreen/buttons, and to move sprites around.

Download here: java4nds_r2.zip — includes the compiled KVM.nds, some examples along with source code, and instructions on making your own .java files.

To use this demo, place kvm.nds, all the *.class files, and all the *.bin files on the root of your flashcart.
Run kvm.nds, then select a .class file to run. There are a few examples testing various stuff.
Don’t forget to DLDI-patch the kvm.nds

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