LABEL BOY
A label maker for the Game Boy (DMG-01) and the Game Boy Printer

Version 0.26, 5 October 2026
by Dr. Marcel Pflug, gameboymuseum.com


WHAT THIS IS
------------

This is not a game. It plays nothing at all.

It is a label maker. Put it in a Game Boy, connect a Game Boy Printer
with a link cable, and it prints whatever is typed into it: text in four
sizes, QR codes, EAN and Code 128 barcodes, lines and frames, on the
self-adhesive thermal paper of 1998.

Nintendo's printer arrived with software that printed photos from the
Game Boy Camera and pictures from a handful of games. It never had a
program that lets its owner decide what goes on the paper. This is that
program, twenty-eight years late and fully aware of it.

Nothing on the cartridge decides what a label is for. A shelf edge, a
box of cables, a jar in the kitchen or a price tag: the owner types it,
the machine sets it. Every code is calculated on the Game Boy itself.
No list of products or addresses is built in.


WHAT YOU NEED
-------------

    A Game Boy           built and tested for the DMG-01
    A Game Boy Printer   or a Pocket Printer, with fresh batteries
    A link cable         one that fits the DMG-01
    Printer paper        no longer made, so the preview comes first
    A flash cartridge    MBC5, at least 256 KB, and 32 KB of
                         battery-backed RAM

The 32 KB matter. Saved labels, the list for serial printing and undo
all live in the cartridge's battery-backed RAM, and a cartridge with
only 8 KB of it cannot hold them.


HOW TO RUN IT
-------------

The file in this folder is an ordinary Game Boy ROM. It needs no BIOS
and no extra files.

    Label Boy v0.26.gb

On real hardware:
    Write it to a flash cartridge and put it in a Game Boy. This is the
    only way to print.

In an emulator:
    Open it. Any emulator that supports MBC5 with battery-backed RAM
    will run it. Everything up to the preview works.

The ROM is 262'144 bytes and uses MBC5 with 32 KB of battery-backed RAM.


WHAT AN EMULATOR CANNOT SHOW YOU
--------------------------------

Printing. An emulator usually has nothing on its link port, and the
cartridge then reports that no printer answers. That is the correct
answer, not a fault.

The preview, on the other hand, is the label itself, dot for dot and at
full width. The printer receives exactly those pictures. What the
preview cannot show is how dark a particular printer burns them into a
particular roll of paper.


THE FIRST START
---------------

    Pick a template: up and down select a part, left and right change
    it, START prints.

That sentence greets you once, and it is most of the manual. A new
label starts from a template (blank, a shelf label, a numbered box, a
website QR code, a cable flag or a Barcode Boy card) and appears as it
will be printed. Small corners mark the part that is selected.


CONTROLS
--------

    Arrow keys      up and down choose a part, left and right change
                    a setting
    A               open, choose, type the text; on a setting, done
    B               back one step; in the keyboard, delete
    START           preview, then print
    SELECT          the next setting

The footer of every screen says what A does on the line the pointer is
on. Behind the last part of a label sit the places to add text, a QR
code, a barcode, a line or a list text, the label settings, the list of
parts and undo.

The same table is inside the cartridge under HELP.


WHAT IS INSIDE
--------------

    New label       six templates and the editor
    Continue label  the label you were working on
    Print again     the last label printed, without losing the current one
    Quick QR code   a code in a few steps: web address, Wi-Fi access,
                    contact card, phone number or any text
    Quick barcode   Code 128 for any text, EAN for shop numbers
    My labels       14 saved labels and the last one printed
    My list         up to 64 lines for serial printing
    Test printer    a check that uses no paper, a dot check, an
                    exposure ladder and the Test sheet
    Printer guide   9 articles about the Game Boy Printer
    Help, About     the controls, the settings and the notices


THE KEYBOARD
------------

Four pages, turned with SELECT: small letters, capitals, signs, and
umlauts with thirteen symbols drawn for labels, among them arrows, a
warning sign, a glass for fragile, an umbrella for keep dry and a heart.
Up from the top row reaches the text itself, where left and right move
the cursor.

Four saved snippets hold text typed once, such as the start of a web
address, and insert it with one key.


CODES
-----

QR codes are built on the Game Boy from what was typed, in sizes 1 to
10 and at all four levels of error correction. Umlauts and symbols are
translated to UTF-8 on their way into the code, so a phone reads them
as typed.

The QR assistant writes the formats phones understand: WIFI: for
network access and MECARD for contact cards. A Wi-Fi label can print
network and password underneath in plain text.

EAN-13 and EAN-8 get their check digit calculated. EAN numbers are
issued by GS1 to the companies that make the goods; for numbers of your
own, Code 128 takes any text and belongs to nobody.

A barcode that does not fit across the paper is turned by ninety
degrees and runs along the roll, where there is no limit to its length.


MORE THAN ONE LABEL
-------------------

A counter in the text prints one step higher on every copy. The list
mark goes further: it is replaced by the next line of My list on every
copy, so one label becomes as many name tags, drawers or jars as the
list has lines.

Between two labels the printer leaves a dashed cut mark, or feeds each
one to the tear-off edge. HELP, Settings chooses which, along with the
darkness and the label width.


PAPER, AND TESTING THE PRINTER FIRST
------------------------------------

Paper for the Game Boy Printer has not been made for a long time, so
nothing is printed without a preview, and the printer is worth testing
before it is trusted.

Test printer asks the printer four questions without using any paper.
The dot check finds heaters that have died in the print head, and the
exposure ladder finds the darkness your paper still needs. The Test
sheet prints eleven numbered labels, T1 to T11, one of each kind; SELECT
shows them on screen first.


BARCODE BOY CARDS
-----------------

Namco's Barcode Boy of 1992 reads EAN codes from cards and turns any
number into a fighter or a monster. The template Barcode Boy card
prints such a code with a new number on every copy. Whether the
printer's dots are fine enough for the reader has not been confirmed on
the device yet.


WHAT IS SAVED
-------------

Saved labels, the last one printed, My list, the snippets and the
settings stay in the cartridge's battery-backed RAM. In an emulator this
produces a .sav file next to the ROM; keep it and they survive. On real
hardware the flash cartridge needs a working battery.


VERIFYING THE DOWNLOAD
----------------------

    Label Boy v0.26.gb

    Size           262'144 bytes
    MD5            {MD5}

If those two do not match, the file is not the one that was published.


TERMS, CREDITS
--------------

See TERMS.txt and CREDITS.txt in this folder. The short version: free
to use and to pass on unchanged, not for sale, and every label made with
it belongs to whoever makes it. The same terms are on the cartridge,
under ABOUT.


CONTACT
-------

Dr. Marcel Pflug
info@gameboymuseum.com
https://www.gameboymuseum.com
