If you press INFO and scroll down to O))), that will list what all the tuners are on.
In Tivo menu, settings & messages, account & system info, DVR diagnostics...
That will list what each tuner, cable card, tuning adapter is doing.
Series 2 (Retired, sold)
TiVo HD 1TB (157 HD Hrs, PLS, "S3HD")
Roamio, Oh Roamio!
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!