Whoa.
In my grade school years, I made many maps of my imaginary world. By high school, I was putting them into my computer, one 16x16 grid at a time. Had to make sure the edges matched up. Then I wrote code to print them on the Epson MX-80 dot matrix. The poster-board I tiled them on was still in the basement, though many of the squares were falling off.
It was easier after I coded a moving 64x64 buffer.
Oh that is a blast from the past - I had an Epson MX-80 printer as a kid connected to my first PC. Many fond memories of trying to make muti-page prints from it... And the dot-matrix sound is still embedded deep in my brain.