We're back with the big #6 issue of our weekly QJ How-To Series, and this one here is a continuation of the discussion we jumpstarted last week on Copyright Issues and Homebrew. Let's pick up where we left off last week, shall we?

As life simulators go, nothing beats the old-school cellular automaton "game" Conway's Game of Life. The latest incarnation of the game, entitled "DSlife", finds its way on the Nintendo DS thanks to the efforts of developer Jeremy Ruten a.k.a. Elektro_Plankton. Find out all the new changes since our previous coverage of DSlife in our full article.

Download: DSlife 3.5
Download: DSlife 3.5 (source code)

Zettablade is letting everybody know about a short tutorial he has over at the forums which will be dealing with how to release your homebrew applications under a General Public License, or GPL/GNU.

A GPL allows a program's source codes to remain free and open-sourced - imagine all those mods for games like CSPSP, and you get the idea. It basically dictates that while any user may modify or even sell (yes, sell - DaX could have been a rich man by now) the original application, they are not allowed to restrict information on the app's source code.

Moving on, the tutorial will dictate the proper format for writing a GPL license, which should be placed specifically at the head of your src files or README. By doing so, anybody who decides to either use or customize your file will first have to agree to the license agreement, hence protecting the file's openness to the public. The tutorial also carries a sample format of a sample license, which should help you get started. Zettablade's guide awaits below at the QJ.NET Forums!

Discuss: PSP Development Forum

Yeah, yeah, we know it's been quite a while since Archeide last updated his SNES emulator for the DS, SNEmulDS. But as the old adage goes, good things come to those who wait. And with the alpha release of v0.4, avid users will find nothing but good things indeed!

But before we get to that, let us remind you that you'll have to patch this v0.4 Alpha release with your DLDI driver because SNES games are loaded from SNES directory. Alrighty then, what can you look forward to in this release? Well, the major change is really just the integration of the CPU engine of SnezziDS, but v0.4 Alpha also includes tons of other updates and additions which you can see in the...

Changelog:

• Implemented MODE 7
• Partial line by line engine for MODE 7 games
• Implemented MODE 3,4 (256 colors)
• Now SNEmulDS uses devkitpro 20 and libfat library from chishm with DLDI support, for better compatibility
• Improved ROM paging, reducing bugs for Large ROMs (> 3 Mo)
• Fixed memory leaks (And consequently, fixed famous “Unsupported Large LoRom” bug)
• Three level of speed hacks : no speed hacks, medium speed hacks, full speed hacks. Each level give various compatibility and speed enhancements.
• Fixed various bugs
• Now SNEmulDS sources are under GNU license, to be compatible with SnezziDS
  

If this is your first time to encounter and use this app, we highly suggest you check out the readme file included in the download. It includes all the info you'll need to know to put you up to speed, and more importantly, how to run this thing on your handhelds.

Download: [SNEmulDS v0.4 Alpha]

Jess Telford loves to set up dominos and knock them down, but just like everyone else, he hates the clean-up that follows. So, he came up with a brilliant idea - DS Dominos. Using the touch-screen feature of the DS, players can set up lines of dominos and watch them tumble one by one with just one quick tap. Unfortunately, the homebrew is still in development. The good news is Jess has released a tech demo of Spring Physics, which showcases a "single spring action upon two points, and the cumulative effect of multiple points joined together to make a string". It's just a small part of the DS Dominos game, but it's worth checking out.

Spring Physics is the simulation of tension forces between two or more connected points, as would be found in a spring, cloth, jelly, and soon, in the DS Dominos game.  The downloadable file contains the full source and the compiled binary. The modules can be plugged straight into any project, but as stated in the GNU General Public License, the code must remain Open Source.

Controls:

• Left Shoulder - Cycle through different 'Springs'
• Right Shoulder - Toggle gravity on/off
• Touch Screen - Use the stylus to drag nodes of the springs around

  

Download: [Spring Physics - Tech Demo]

Here's one homebrew application for the hardcore DS developer - DS Debugger v0.11. As the name says, the app allows developers to interactively debug their applications running on a real Nintendo DS. Created by Simon Hall, the app initialises the network, connects to the PC-side stub and installs the breakpoint-catching code. A function needs to be added to a timer or into a main update loop which polls for commands from the PC-side stub. This picks up commands to add breakpoints or read memory from the PC. Without this function, breakpoints can't be set.

On the PC-side stub, a Java application translates the complex commands from the GNU debugger (GDB) into simple operations which the DS stub can execute. The Java stub relays messages from the DS to GDB when things like breakpoints or illegal memory accesses occur.

If you're new to this sort of thing, you really have to go over the readme file. It's a long read but you'd feel better after knowing how the app works. If you already know how it works and you're just rarin' to test the app, here's a list of what it can do:

• suspend the program at user-defined breakpoints
• step individual instructions, assuming the program has paused at a breakpoint
• step whole lines of source code
• inspect memory locations - and assuming a symbol table is present in the original ELF - variables and other structures can be read and their values can be changed
• inspect the state of all registers in the user ARM execution mode - including the program counter, link register, stack pointer and status register
• evaluate all types of ARM branch and condition instructions, allowing you to follow the execution of code properly in most circumstances
• It has a blacklist function, which defines which functions shouldn't be stepped into (when a b/bl/bx instruction is encountered). This is useful to prevent the debugger from stepping inside itself, or functions used by the debugger. If you do step into the debugger, it will probably get into an endless loop and hang.
• It can break on invalid memory access, signalling a SIGBUS message to the host debugger.
• It can break when an invalid instruction is executed - this signals a SIGILL message to the host debugger.
• Both these exceptions destroy the original instruction in memory, so if you read the original opcode back from DS memory you'll get the breakpoint stub opcode instead. To get the real opcode, disassemble the ELF instead. If there's demand for having the real opcode left in memory I'll make the changes required to fix this.
• with minimal work, it ought to be able to co-exist with applications which use sgstair's wireless library

Of course, as this is a work in progress app, there are things it can't do (the readme file has the complete list), but I'm pretty sure Simon is keen on releasing updates in the future.

Download: [Wireless Debugger v0.11 for DS]

NDS Managedbuilder has been updated to v1.1.1. The latest release contains fixes for some minor bugs in the NDS Managedbuilder 1.1.0 (the first public release). It also has full date functionality. NDS Managedbuilder is an Eclipse CDT plugin for C/C++ development especially for the Nintendo DS target system.

Easy to use managed build system based on the GNU toolchain
- Supports C and C++ projects, also ASM Programming
- Different project types

- NDS ROM - ARM9 Sources + NDS Tool

- NDS ARM7 Code - ARM7 Sources + ObjCopy

- NDS ARM7 Library - generates a static link lib

- NDS ARM9 Library - generates a static link lib

Requirements:
- Linux and Windows XP OS
- Eclipse 3.1.x or higher (may also work with 3.0)
- CDT 3.0.x or higher

Installation:
- Install the plugin using the updater. Simply add the site to your update sites and search for new features to install
- Put devkitARM in your system PATH.

The author prepared a small presentation on how to use the basic features of NDS Managedbuilder and you can see it here.

Download: [NDS Managedbuilder v1.1.1]