You can connect a DVD recorder's Line Input (typ. L1, L2 or L3) to one of the Comcast outputs and make a DVD copy much like a VHS tape...press play on Comcast and Rec on DVDR.
There are other features of DVDRs that make them slightly more complex than a VHS rec. if you choose to use those features. There also may be one or more settings on the Comcast box you need to make to get an output signal to the DVDR...some boxes have an "Out to VCR" or similar connection.
Some DVDRs have a Hard Disk Drive (HDD)...Philips DVDR3575H for one, $298 at Wal-Mart and other places...that makes time-shift recording of programs, transferring from STBs, and copying to DVDs much easier than a DVDR with just a DVD drive. High-quality DVDs cost ~30 cents each.
Thanks for the info but I should have given more into. I don't have a DVDR, I have a PC with DVD burn capability. The DVR has a USB port. Can I just connect that to the PC and have the DVR show up as another device, like an ipod?
I doubt "they" would make transferring DVR recordings to something you can make unlimited copies of that easy, but only way to know is hook up and see if the PC recognizes the DVR and can transfer an MPEG2 video stream...I believe virtually all STBs disable that function???
No you can't record from a USB port - the DVRs don't support that as an output, its not supported now and is only planned as an input anyway like for a keyboard. Even firewire outputs are encrypted.
You can only record from the DVR's analog video and audio outputs - like the composite (yellow RCA jack) or s-video outputs.
You would need an analog video capture device in the PC as well as software for encoding to DVD compatable MPEG2 format. Then you need software to create DVD format files and finally software to burn the formatted files to a DVD.
Its rather complicated if you haven't done all that before. Buying a cheap standalone DVD recorder for <$100 might be the easier way to go and doesn't require special knowledge.