marlin/buildroot/share/PlatformIO/boards/at90usb1286.json

{
  "build": {
    "core": "teensy",
    "extra_flags": "-DTEENSY2PP  -fsingle-precision-constant",
    "f_cpu": "16000000L",
    "mcu": "at90usb1286"
  },
  "frameworks": [
    "arduino"
  ],
  "name": "Atmel AT90USB1286 based",
  "upload": {
    "maximum_ram_size": 8192,
    "maximum_size": 122880,
    "require_upload_port": true,
    "protocol": ""
  },
  "url": "https://github.com/MarlinFirmware/Marlin",
  "vendor": "various"
}