Skeetendo

TCG disassembly

That's impressive. I will probably see what I can contribute soon. Feel free to contribute the the tcg disassembly. I haven't touched it in a while, just because i finished what I was mostly interested in; music, cards, decks, text and graphics. And I get bored with just dumping asm.

Here's something fun: https://youtu.be/wL2qeDQjozQ

Eventually, I think it would be cool to make a "Pokemon Pinball Gen 2" game.

I've started writing a tool that will edit stage tiles and collision maps.  Here's an early screenshot of the collision mask functionality:

In Pokemon Pinball, there is a bonus reward where two Pikachus can save your ball in the bottom corners of the stage.  When they are in the act of propelling the ball upward, a raw audio clip is played that sounds like "Piiiiii-Kaaaaaaa".  It turns out that both Pokemon Pinball and Pokemon Yellow Version share the same code that plays audio clips.  Additionally, Pokemon Pinball borrows two Pikachu sound clips from Yellow Version.

In the ROM, the actual sound data is stored as 1-bit pcm.  "pcm" stands for pulse-code-modulation, which is a fancy way of saying "sound wave amplitudes".  Since the pcm is only 1-bit, each sample in wave is either maximum or minimum amplitude--"on or off".  Of course, this results in a very low-quality sound. That's okay, because the GameBoy wasn't designed to play pcm audio.

Then how does Pokemon Pinball/Yellow play the pcm data?  The playback routine writes volume data to the GameBoy's wave channel (channel 3).  The logic goes like this:

1. Read single 1-bit pcm sample

2. Write either 100% or 0% volume to the wave channel

3. Wait a set number of CPU cycles

4. Repeat until the pcm data is over

Now that we know the audio's data structure (1-bit pcm) and how the game interprets that data, we should be able to do two things:

1. Convert the 1-bit pcm data from the game into a .wav file

2. Convert an arbitrary .wav file into 1-bit pcm data tha the game can understand

Converting 1-bit pcm data into a .wav file is trivial, and it turns out converting a .wav into a 1-bit pcm stream is also pretty straightforward.  This allows us to use .wav files in the pokepinball and pokeyellow projects.  At compile time, the .wav files are converted into the 1-bit pcm format using a python script.

Here are the .wav files ripped from the games:
https://github.com/pret/pokeyellow/tree … achu_cries
https://github.com/pret/pokepinball/tre … ound_clips

This also allows you to replace any of Pikachu's cries in Pokemon Yellow, for example, with your own recorded voice.  Here's me testing that out:
https://www.youtube.com/watch?v=pChFdI2NnjQ

Here's a fun animated gif showing the ROM coverage of pokepinball over time: http://i.imgur.com/ZR6a7EW.gif

I changed the Pokedex so that it shows you the ball that you caught the pokemon with:

Pokemon seen/owned flags are just stored as flags, so I had to update the logic for that data to store the pokeball type when capturing a pokemon.

This disassembly is nearing "completion", meaning there are only 19 INCBINs from baserom.gbc remaining.  I've been working pretty hard on that recently--I think there were ~300 INCBINs 3 months ago.  Once the baserom.gbc dependency is removed, I'll work on taking moving stuff out of main.asm, since it's currently 53,000 lines long.  After that, I'll probably make some fun hacks with it to weed out any possibly-missed hardcoded pointers.