HelenOS sources
KC_N1 126 uspace/drv/hid/adb-kbd/ctl.c [0x53] = KC_N1,
KC_N1 156 uspace/drv/hid/atkbd/atkbd.c [0x69] = KC_N1,
KC_N1 139 uspace/drv/hid/usbhid/kbd/conv.c [0x59] = KC_N1,
KC_N1 149 uspace/drv/hid/xtkbd/xtkbd.c [0x4f] = KC_N1,
KC_N1 210 uspace/srv/hid/input/ctl/sun.c [0x70] = KC_N1,
KC_N1 190 uspace/srv/hid/input/layout/ar.c [KC_N1] = '1',
KC_N1 219 uspace/srv/hid/input/layout/cz.c [KC_N1] = '1',
KC_N1 198 uspace/srv/hid/input/layout/fr_azerty.c [KC_N1] = '1',
KC_N1 199 uspace/srv/hid/input/layout/us_dvorak.c [KC_N1] = '1',
KC_N1 193 uspace/srv/hid/input/layout/us_qwerty.c [KC_N1] = '1',
HelenOS homepage, sources at GitHub