Fun fact: The iconic Nintendo logo that scrolls up the screen when the Game Boy boots is stored in the bootrom built-in to the device, but that's not where it's loaded from. Instead, it's loaded from the cartridge, and then the bootrom compares that version to the internal data and refuses to boot if they don't match. This seems silly at first, why load the data from the cartridge if it has to be the same thing every time and you already know what it should be? The answer is DRM! By forcing developers to include the Nintendo logo in their cartridges, Nintendo could sue anyone distributing unapproved cartridges for intellectual property (copyright/trademark) violations. Unfortunately for Nintendo, the bootrom actually reads the logo data twice, once for drawing it to the screen and another time for checking it against the internal data, so with some clever hardware tricks you can make a cartridge that passes the check without displaying any protected material.
