Palm OS Gameboy Emulator in the works
Story by: Atomic212
March 29, 1999
A Palm Infocenter exclusive
So you want to play gameboy games on your PalmPilot? That may be a reality soon.
Considering the two devices similarities it's hard to ascertain why this hasn't been done yet.
Gameboy has an 8-bit z80 processor with a
clock speed of 4.19Mhz, and a 160 x 144 pixel screen with 4 shade greyscale. As a general rule
in emulation you need a system at least 3 times as fast as the original system to be emulated. Palm's
16Mhz dragonball processor should be enough to handle that task.
Palm Infocenter recently interviewed Maven, who is currently working on making Palm Gameboy a reality.
Maven is writting the emulator from scratch, others have tried to port the
Virtual Gamboy emulator to the PalmOS
but gave up on the task because of the palm's limited speed and memory. He is also writting the code
in assembler, since that's the only way to get enough speed for emulation (the C compilers are not very good at efficient code). Right now the CPU emulator has been built and is running without problems, his next step is to emulate the screen and sprites system. Maven plans to release a demo beta as soon as the ever popular
Tetris game is fully playable.
Stay tuned to the Palm Infocenter for more updates on this story, we will also have the demo
availible to download as soon as it is released. Read on below for exerpts from the interview.
Palm Infocenter: What will you call the emulator?
Maven: Actually, I've been calling it PalmBoy, but Palm Computing has informed me they consider that a violation of their trademarks, so I have to come up with a good name. I am open to suggestions, and maybe even a naming contest! (I just can't have the name 'Palm' in the name of the product)
How do you plan to implement the controls, such as the d-pad, A & B, etc.?
Also, do you plan to add support for the GoType keyboard?
The directional pad will be used by the PalmPilot's hardware buttons. Up/Down corresponds to the Palm up/down, right/left will be the scheduler/ phone book keys, and A/B will be the ToDo/Memo keys. This will probably be configurable by the user. Obviously, the design of the Palm keys isn't the best layout for joypad/buttons. Oh, well.
The start will be through the 'find' button. Other options, such as loading games will be available through the menu button, which will also pause the game.
At this point, I don't have plans to support any keyboards.
Will gameboy roms need to be converted into a .pdb format or some other method to transfer them to a pilot?
Yes, the ROM's will have to be downloaded into the Palm as a .pdb file from a desktop PC. I will have a conversion utility to put the ROM's in a format suitable for the Palm. At this point, I haven't tried any larger than 64k, although I'm sure it can be done.
When do you expect to near a completion date? Can we expect a beta?
Completion? "grin" I'm hoping to have Tetris running within the next week or two. Other games will take longer.
I will release a demo version when Tetris is fully playable.
Will games such as Marioland and Zelda be fully playable?
Or will the emulation will be up to speed or comparable to the gameboy?
As I have said, I am still nervous about the overall emulation speed. I may never be able to emulate the sound of the GameBoy, and I'm sure I won't be emulating any add-ons. I would like to emulate the Color GB (without the colors, of course) if I find the speed is sufficient- The Color GB's clock speed is double the standard GameBoy.
There is no reason why most GameBoy games shouldn't run if Tetris runs correctly.
What other palm apps have you developed or are planning?
I've actually played with a FlightSim program for the Palm. I am using the Emulator as a way to really learn 68k assembly language. Once I have that down, I hope to write other games/simulations.
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