I still have an RCA VCR that does that (not that I have a cable signal to feed it anymore). The manual makes some vague references to how it works, but I'm gue

I still have an RCA VCR that does that (not that I have a cable signal to feed it anymore). The manual makes some vague references to how it works, but I'm guessing it's pretty similar to your Panasonic. It was fascinating to watch (well, hear, more accurately) exactly how it did it too. Once a timed recording finished, it would rewind the tape to the start of the recording and "watch" the show at high speed. When it encountered a commercial it would slow down, rewind a bit, and somehow mark the start of the commercial segment on tape, speed up for a bit and somehow mark the end. When playing back it would turn the screen blue and fast-forward through the previously marked commercial segments automatically. The accuracy was very impressive.