Game Boy Printer

The Game Boy Printer was a little thermal printer on the end of a link lead, and a surprising number of games could use it: the Game Boy Camera above all, but also Pokémon’s Pokédex, Link’s Awakening DX’s photo album, Super Mario Bros. Deluxe’s calendars and cards, and more.

As of v0.11.0 it is in the room. The game sends the picture down the cable exactly as it did to the hardware, the paper feeds out of the slot line by line as it prints, and when you tear it off you are holding the print, and it is saved as an image file.

Setting it up

1. Download the printer’s core. Open CORES → BIOS / Extras, pick Game Boy (or Game Boy Color), and download the Game Boy Printer row. The printer runs a small emulator of its own, so it needs this once.

2. Spawn the printer. It is on the Game Boy’s and the Game Boy Color’s spawn cards, next to their link leads.

3. Cable it to the Game Boy. The printer’s EXT.IN socket on the back is the small one, so:

   • from a Game Boy Color, use the CGB-003 lead (small at both ends);
   • from an original Game Boy, fit the DMG-14 adapter into the Game Boy’s large socket first, then run the CGB-003 from the adapter to the printer. That is how the printer was sold outside Japan.

4. Switch the printer on with its POWER switch, and the Game Boy too.

5. Print from the game. In the Game Boy Camera: open a photo, press SELECT, and choose print. Every game puts it somewhere different.

Either Game Boy core works on the other end of the lead, whether Gambatte or mGBA.

The paper

The print comes out of the slot as it burns, and stays there, hanging out of the printer, until you take it. Print several times and the strip just gets longer, the way a roll does.

• FEED advances blank paper.
• To tear a print off, take the paper with the trigger. (Not the grip, and not a brush of the hand: a print should never be thrown away by accident.) What you are holding is the print, as a picture at the paper’s real size, and you can put it down anywhere in the room.
• Switching the printer off tears off whatever is hanging out first.

Where prints are saved

Every torn print is written as a PNG:

Platform	Folder
Windows	%USERPROFILE%\retroxr\prints\
Linux / macOS	~/retroxr/prints/
Quest	prints/ in the web file manager

The image is the printer’s 160 dots across, centered on the real paper’s width.

The sound is a best guess

You will hear the stepper motor and the print head. Nothing published describes what the real MGB-007 sounds like, and there was no unit to record, so the sound is synthesized from how the mechanism works. A recording of a real one would be very welcome, so please see contributing.

Over netplay

A printer cabled to a Game Boy joins that Game Boy in a netplay session, and every player prints the same paper. To press FEED or tear the paper off, you need to be the player holding it. Everyone needs to be on v0.11.1 or later, with updated cores. See netplay.

Known limits

• On mGBA, pulling the lead out while a netplay session is running can stall the session. Plugging in and printing are fine; on Gambatte, so is pulling it.
• Only a handful of printing games have been tried so far. The Game Boy Camera and Super Mario Bros. Deluxe are known to work. If another game will not print, please report it.