```
kldload acpi_ibm
# try various features...
systctl dev.acpi_ibm.0.kbd_backlight=2
morse -l "SOS" >/dev/led/kbd_backlight
sysctl dev.acpi_ibm.0.kbd_backlight_ledon=2
systctl dev.acpi_ibm.0.micmute_led=1
systctl dev.acpi_ibm.0.micmute_led=2
morse -l "SOS" >/dev/led/micmute
echo "0" >/dev/led/micmute
```