Gaming on Thermal Receipt Paper is Possible, Not Practical

A YouTuber named smill just finished a playthrough of Minecraft using only a receipt paper for visuals. He turned off his monitor, took screenshots of the game one by one and fed them straight into the printer. Each frame came out on a strip of thermal paper, a long blurry record of his adventure. By the end he had defeated the Ender Dragon, so you can finish the game this way if you have the patience and a stack of paper rolls.

Thermal printers work by heating special paper with tiny elements in the print head. Dark pixels get hot spots that darken the surface, light areas stay white. No ink ever touches the paper. Smill hooked up a basic model to his PC via USB and built a simple app to handle the rest. The program grabs a screenshot of Minecraft every second or so, resizes it to fit the narrow paper and converts the colors to black and white patterns the printer understands.

Too many frames and the print head overheats from constant heating, so speed is key here. Smill settled on one frame per second after experimenting and found that higher speeds caused jams or distorted output. Early runs used printed Twitch chat messages or camera views to calibrate the timing. For Minecraft this meant 0.5 to 1 FPS in practice, so gameplay was an anxious wait between updates.

Viewing those prints required some ingenuity, so Smill built a DIY respooler out of plastic blocks, chains and wheels. It wrapped the output paper back into a loop so he could flip through the frames like a hand cranked flip book. Multiple rows of paper were stacked during longer sessions but jams occurred frequently especially during hectic moments. He navigated by staring at the blocky monochrome graphics, listening to the game sounds (sheep bleats or enderman hisses) and relying on muscle memory from previous games.

Minecraft is a game that can work with a blocky look, but after a while, things start to go wrong. Your inventory slots simply fade into nothing on the interface, forcing you to click blindly to create tools or sort things out. Dark sections, such as the Nether, will simply burn out your printer because they are so black, and then you reach the End, where everything is just this pristine sky and the dragon vanishes completely. Smill was creative enough to employ hitboxes in debug mode to make the boss appear as a faint silhouette.

The coordinates on the F3 screen were nearly useless for printing, therefore he had to rely on the assistance of other speedrunners to understand the pathways for his seed. Paper was another issue; it ran out quickly, taking around 10 to 15 minutes each roll, or 600 to 900 images. Smill had purchased ten rolls but only used five while attempting to resolve issues with his printer and software. He had a run cut short in the Nether by a ghast fireball, and another messed up at the End when he spent all of his beds on crystals. But he eventually managed to put something together with a super-optimized world seed, fast portals, and a significant amount of stuff.

Smill’s printer app began as simple as you might think, with only one button to transmit anything to the printer. But he soon began to add automated timers and improved contrast to his hotbar. Not that anybody can see his code just yet, but if you know the fundamentals of programming, you should be able to recreate it using certain printer control and screen capture libraries. Simply connect the hardware, feed screenshots through with a one-second delay, and watch the paper fly out.

It’s similar to what Bringus Studios did with Doom: they sent the game frames to an Epson thermal printer and just waited up to four seconds every output to get the demon entrails on paper. It slowed movement significantly, but players were still able to evade and take potshots by simply glancing at the growing strip. Both designs simply employ the printer as another display, allowing the PC to continue running the game at full speed in the background while the paper serves as the only window.
[Source]