said by norbert26:TIVOs will not receive any digital channels without a cable card not even in the clear ones. Without a cablecard it will only get analog which does not apply on FiOS .
Just to build on what Zero and jcondon8 said, this is not true at all.
You can do a manual channel scan on a TiVo setup without a CableCARD and it will find any clear QAM channels. The issue is that guide data will not be mapped to the channels correctly. If you have a hacked TiVo 3 or HD, I (along with others' previous work) wrote a script that will map your channels to the TiVo guide data.