Access Cable TV on computer without TV tuner card

Setup: I am Comcast and subscribe to both Cable TV and internet services. I watch cable without a cable box and have a motorola cable modem for internet.

Question: I want to watch my cable (and record if possible) from my computer without having to split the cable and purchase a TV Tunner card. Is there any way to download a special program or get my enternet browser to view the cable stations coming into my modem?

thanks,
Steve