• Adafruit_Thermal library for Arduino.
• LCD Assistant — optional bitmap conversion utility for Windows.
• Processing language — needed for bitmap conversion for Mac or Linux (and optionally Windows). DOWNLOAD VERSION 1.5.1, not the 2.0 beta.
• Thermal Printer User Manual.
• An older version of the Thermal Printer User Manual.
• Thermal Printer Product Sheet.

Firmware Changer

If you'd like to risk it, you can revert/change the firmware using this tool that is from the manufacturer. We haven't tried it. It's completely utterly unsupported and you may break your printer. We won't replace it if it stops working due to a firmware change!