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.
Original S1 (Recycle Heaven)
Series 2 (PLS, sold)
TiVo HD (XL, PLS, "652")
Juliet Basic (4XL, PLS)
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!