Kirby Tilt n Tumble and GBA-SP

[CrazyImpmon]

I've decided to see what it would take to make this oddball GBC game work correctly with the new SP. The tilt sensor is in the chip on the very top of the cart, just a bit to the left (you should be able to see it easily) It is a ADXL202 X-axis and Y-axis tilt meter (basically pitch and roll sensor). I have bad news and good news...


Bad news: since there's only 2 output (X axis and Y axis) it's not going to be easy to flip it.

Good news: you can desolder the whole chip, rotate it 180 degrees and then wire the chip pins to the original pad. Since it's rotated 180 degree, it'll work with the SP. But it will no longer work with with GBA or GBC.

Alternatively someone could get the ROM of the game, hack in to add a menu at startup to ask if the player is using SP or GBA/GBC and if it's SP, flip the control and then play as normal. But you'd need an EPROM burner and the resulting modified game cart would have ugly black chip sticking out and it'd be a bitch to make the cart fir back in the GBC.

Another thing, for using the game with GBA Player for the GC, just take the whole GC and put it in your hand with the cart slot pointing away from you. Tilt and roll the whole 'cube to control Kirby.

[Bratwurst]

Originally Posted by CrazyImpmon

But you'd need an EPROM burner and the resulting modified game cart would have ugly black chip sticking out and it'd be a bitch to make the cart fir back in the GBC.

I haven't looked into this much but isn't there a one-shot flash chip or something with the proper pin number to be used instead? You can get some pretty thin ones.. only ones I have experience with are the AM29F400BB and AM27C010 though.

[CrazyImpmon]

You could try using SMD PROM instead but most home EPROM burner are designed for standard DIP package so you'd need an adapter to handle small SMD chips.

[Bratwurst]

I'm no stranger to adaptors.

Semi-related- any idea what sort of chip I might use to replace the program on a GBA cart? I have this homebrew project of mine.. already have a flash cart, but you know, the novelty of a dedicated cartridge with custom label art would be nice to behold.

[CrazyImpmon]

I'm not that much of an expert on SMD chips but flash ROM or EEPROM are typically 28xxx and 29xxx while EPROM are 27xxx I haven't used a PROM in oh about 10 years and I can't remember the number. I do know one thing, soldering in 20 or 3 tiny pins is a major pain in the rear plus there's a good chance the replacement rom is not pin compatible with original ROM chip. It's the case with NES, SMS, and Game Gear and there's no reason it'd be that easy with GBA and GBC.

You may need to look for a Gameboy dev web site for more technical (and accurate I hope ) information as well as finding a way to reprogram GB/C/A ROM if your intention is to change something other than graphics.

If I wanted to fix my Kirby game, I'd take the easy way by removing the tilt sensor chip, rotating it and adding in wires. Then hot glue the whole thing in place so it won't shift at later time.

[DogP]

Just a crazy idea... I've never actually seen the internals of a kirby tilt game, but could you put a switch on the cart that just flips the x and y axis' of the tilt sensor? IMO that'd be a little easier and more universal, but without seeing the internals I guess I couldn't say for sure. Maybe I'll have to pick one of these games up, it was kinda fun anyway :P.

DogP

[CrazyImpmon]

The switch idea won't work since there's only 2 lines (X and Y) and flipping them would get strange result. Tilting the GB/GBA forward would cause Kirby to roll to the left, tilting to the left would cause Kirby to roll forward, down to right, and right to down.

It's only good for a practical joke but that's all. And if you want to quickly find that game, just look for an abnormally large game cart *about 1/2" taller than normal GB cart) and ALL IN TRANSPARENT PINK.

[DogP]

No... sorry, that's not what I meant... I meant a switch that would flip the x and also flip the y, not swap them. Depending how the sensor is wired, I think that would be a easy mod.

DogP