dual boot ds cartridge?

[stuntpenguin007]

If I could find an eeprom of sorts that ran off of 3.3V and had 4 i/o's could I program it with a small homebrew program and wire it directly to gnd, +3.3V, and i/o 1-4? it would have a switch to change between the mask rom with the game on it and the homebrew app.

ds cartridge pinout found here http://darkfader.net/ds/files/cartridge.txt" onclick="window.open(this.href);return false;

I know I could just get a flash cart for homebrew - in fact I have one... but what I plan to do is make a game save editor built into the cartridge.

So is there any address latching fancy stuff I don't understand I'm missing here or should that work? I guess I don't really expect it to work, and I'll end up getting shot down by 20 people... but oh well

[palmertech]

A save game editor? For what game?

Beyond the reasons it would not really work, I doubt you have the skills to make the software needed.

[stuntpenguin007]

I've done a small amount of ds coding, and the game is pokemon platinum. You can just edit the save with a hex editor to modify values like money (if I were to use hex comparison to find the values) so I don't think it would be too ridiculous of an app - in fact I could attempt to make it now and use my slot 2 card to try it out.

I'll be gone this weekend thouhg so I don't expect to get very far, that is if I can figure it out.

[palmertech]

My DSTT allows you to edit cheat codes, you could easily make one that bumped your money a certain amount every time you did a certain key combination; If I remember correctly, there are 3 keypress sequences it will recognize off the bat.

[stuntpenguin007]

are you suggesting that I just make a cheat to do it? I'd like to work on my coding skills even if this just blows up in my face.

Right now I'm trying to get an alpha version going. I've found that in a 512kb save the hex value for money is located at 0000007C, 0000007D, and 0000007E. By starting with 0000007E and working your way backwards you get the hex for money.

example: Say those 3 offsets were AC 4C 00. You read them from right to left 00 4C AC and convert it to a decimal and thats how much money you have.

In the alpha I plan to have the user select how much money they want by using the d-pad. When their ready they can hit start and it will display the hex form on screen.

So overall it won't even touch the save file but It'll be a step in the right direction. After all, it's going to be an alpha version.