4-e

A project to send Super Mario Advance 4 e-Reader cards from one Game Boy Advance running 4-e to another running the game, using homebrew and decoded .bin versions of those cards instead of printed cards an an actual e-Reader.

It has been tested to successfully and reliably send demo, power-up, and level cards between mGBA multiplayer windows as well as real Game Boys Advance and Analogue Pockets.

I've written more about 4-e on my blog.

Usage

1. Build the 4-e.gba ROM or download it from releases.

2. Using gbfs-web, attach the e-Card .bin files you wish to use to 4-e.gba, and save a new ROM.

   • You can also use the standard tools from GBFS to create a GBFS file, then concatenate it to 4-e.gba. (These tools are also included in the "gba-tools" package in devkitARM.)

3. Link two Game Boy Advance systems with a link cable. The game must be player 1, and 4-e must be player 2.

4. On the first system, run Super Mario Advance 4.

5. On the second system, run your custom 4-e ROM.

6. Pick the e-Card you wish you send from the list. If your GBFS file only had one e-Card in it, it will be selected automatically. From this point on, you can cancel and reset by pressing B.

7. On the first system, start the e-Reader communication process. 4-e will connect to the game automatically and try to send your card.

8. When the game has finished, press any button on 4-e to reset so you can send another card if you wish.

Troubleshooting

4-e doesn't respond when I start communication

Check that your link cable is connected firmly and correctly.

• If you're using the official Nintendo link cable, it must be connected with the purple end to the game and the gray end to 4-e.

• If you're using the Analogue Pocket link cable, it must be switched to GBA mode, not GB/C mode.

Thanks

4-e wouldn't exist without:

• devkitARM

• gba-makefile-template

• GBATEK (specifically the section on GBA Communication Ports)

• GBFS

• mGBA