Can you convert your TiVo into a mass storage device or use it as extra storage for your new TiVo?

No, you cannot convert a TiVo into a mass storage device or use it as extra storage for another TiVo. TiVo devices are designed to function as standalone DVRs with specific software that does not support storage expansion or repurposing. While some TiVo models allow for external hard drives to be added for additional recording space, they cannot be used as general mass storage devices for other applications.