k6lcm turned an original Nintendo Entertainment System into a flight tracker with NES Radar, which sends live aircraft positions through the second controller port at 9600 baud. The project uses no radio hardware, so the console needs only a cartridge, a cable, and a nearby computer.
NES Radar on GitHub
NES Radar is open-source under the GPL on GitHub, and Levi tipped the project, which puts it in the middle of a current wave of air traffic visualizers. The software can accept an ICAO code such as KATL and draw traffic on the console, so a user can point the system at a specific airport instead of staring at raw data.
Second controller port serial link
The key trick is the second controller port, which NES Radar treats as a serial port while a nearby computer runs a Python script that fetches aircraft positions. That setup keeps the NES itself free of a radio receiver, and it also avoids the need to stuff extra networking hardware into the cartridge.
The ROM cart holds the software, but the cartridge does not contain an ESP32 or a PicoW. That detail strips the build down to the parts that actually matter for the display path, while the computer handles the internet side and the NES only renders what it receives.
8 sprites at KATL
The software is limited to 8 sprites, so a busy airport such as KATL will not fit every aircraft on screen at once. That limit is the real constraint for anyone judging the project as more than a novelty, because the console can show a live view only within its sprite budget.
A similar trick was used for satellite tracking on the NES some years ago, and NES Radar follows that idea with ADS-B and free APIs for airplane trackers. The unresolved question is how much traffic it can realistically display beyond the 8-sprite limit when the airspace gets crowded.
