A few years ago I made the "crashterizer" (http://xkeeper.net/crashterizer/); a online page that will take an image and turn it into a bunch of garbled mario 1 tiles, like this https://icosahedron.website/media/sWp2D0_4C6N0mMYft1s
before i put the source of it online, someone actually figured out the algo it uses (it isn't complex) and managed to write a message using it http://xkeeper.net/crashterizer/r/1429022942.4929.png https://icosahedron.website/media/ACmWopt-NBcD1BzZS7o
maple classic™ 
@Xkeeper ??????? how??
@Xkeeper but how would one figure that out without the source
@squirrel experimentation. this image came directly before it and shows every single tile laid out in reverse order http://xkeeper.net/crashterizer/r/1429022458.8547.png
@Xkeeper was the sample file 2040x8 or 255x1? is it just shades of gray?
@squirrel the output is the same size as the input (to an 8, one way or another). it was likely just a gradient from white to black, yes (the original doesn't exist)
@squirrel if you know how it converts source image -> mario 1 tiles, you can upload an image designed to output that.
think of it like something that rot13s every post: if you put in something rot13'd, it will come out normal. not QUITE the same, but close