Morphing Palm to GB and back.

Palmboy is discontinued

The homepage of PalmBoy was actually With some luck, it still exists, please give it a try; there was so much more information than is presented here. This page just provides rudimentary stuff.

Because of several reasons, "PalmBoy" had to be renamed to "Phoinix", see its homepage. This is the current emulator, don't use PalmBoy any more! This page is for reference purpose only! Please update your bookmarks and links. If you followed a link from another web site, please inform the administrator of that site to update that link, too! Thank you all for being with me all this time, and you're welcome on the new pages!


Somewhen in 1999 my friend Till Harbaum came along and showed me his new toy - a "Palm III" PDA. Chatting began and carelessly I promissed to write a Gameboy emulator if I had such a PDA. He took me at my word and when he got his new "Palm IIIx" I had to start the work.

As an old Atari ST fanatic I decided to port some Pilot tools to this outdated system. The second main cause to develop on the ST was that their CPUs are equivalent. So I made STemBoy as core development project. To create PalmBoy I copied the emulator kernel and added the user interface and support functions.

This went until v.3.14159 which was made between december 2000 and february 2001. Then my Atari ST broke down and I got a Linux box. So I decided to change the PalmOS parts from assembler to C and leave STemBoy alone.

PalmBoy is put under the GNU General Public License.


To get the emulation as fast as possible nearly no checks are made and the memory protection had to be switched off. This leads to a potentially very dangerous program - every single byte of your Pilots databases and programs in RAM can be overwritten! Serious and heavy testing revealed no data losses, but it's a very good idea to hotsync your databases before trying the emulator with new games until you gain confidence in the combination of emulator and emulated game.

Download: Archive with compiled program and utilities, no games, 240KB. Archive with some converted free games, 42KB. Converters (Source/Linux/DOS/Mac/Windows), 113KB. Archive with source code and compiled program, 309KB.

Status, a brief history of versions:

v.4.0 beta2

The state of a currently played game is saved on exit. After relaunch, the game is continued.

v.4.0 beta1

All sources converted to be compileable with the GNU tool chain. The kernel is still assembler code, but all other parts are now coded in C.

v.3.3b (last public release)

Sorry! The bugfix had to be fixed...


The "bug" in the MBC1 code is corrected, hopefully! There are no more changes from v.3.14159...

v.3.14159 "¶ gotchu!"

This version emulates nearly everything I planned. Additionally it supports cartridges upto 4 Megabytes - anyone with a Pilot with more than 8 Megabytes RAM? The adjustment for the grayscale can be done with Grayhack, a module for X-Master (Freeware), or HackMaster (Shareware), or EVPlug (sorry, no reliable download source known). Till wrote another tool to convert Liberty databases to PalmBoy databases and more: Real Freedom. And yes, you may now hunt those pocket monsters...

Known bug:

v.3.1 United colors of screens

Now every Palm Computing® Platform with OS 3.0 or better should be capable of running PalmBoy. By changing the way to switch into grayscale mode the flicker on some newer devices went away - but the contrast went down a bit as well. Please read below in the notes about this!
You may now use the contrast or brightness dialogues while running a GB game to adjust the screen to your taste. Battery and other alarms should now come through, but I couldn't test this really.

Known bugs, aside from missing functionality:

v.3.0a All vis(it)ors welcome!

The bug which crashed Visors is catched and smashed! For users of OS 3.5 there's another correction: Palm introduced a new event that caused PalmBoy to return to the main menu after switching off and on. This is fixed, too.

v.3.0 "Aller guten Dinge sind drei."

Third big step: the interrupts, many games should run! The last main thing left not yet emulated is the serial interface. I've some ideas for enhancements, too...

Known bugs, aside from missing functionality:

v.2.0 Intermediate version to keep you stick at it

Second big step: the screen was nearly full emulated: background, window and objects. Even the palette registers and scrolling were taken into account. Still missing were the interrupts, therefore only few (free) games were playable.

v.1.0 The appetizer

This version only rendered the background - that's why only some games worked. All unimplemented input/output operations were reported as errors, this is silently ignored in the next version.

Known bugs, aside from missing functionality:

Horizontal Bar.

Who to blame:

Back to my home page.

Comments about PalmBoy: [email protected]

Other comments and such stuff go to: [email protected]