How-To: MacOS X Firewire HDTV recording - AVS Forum
MacOS X is currently the only viable solution for recording HDTV via firewire using an emulated D-VHS deck. With a properly setup system you can record and playback cable and OTA HDTV with no loss in picture quality or sound. As for as alternatives, there is a beta product called Firebus for Win XP but it is extremely buggy and the development status is unclear. The beta is also incidentally closed if your interested. Some have also reported some success recording with Linux but it is far from plug and play. For the moment the Mac is the best choice for the task. Below you'll find the requirements and and some instructions for getting started recording HDTV with a Mac.
http://www.macosxhints.com/article.php?story=20040426151111599 - Record and playback high definition TV signals
http://seth.mattinen.org/notes/hdrec.php -
I've just started this project, so these notes will be updated as I progress towards creating a working HDTV recorder out of an old Macintosh. I'll be using MacOS X for the operating system and FireWire (IEEE 1394) for the transport connection between the HD tuner and computer. A recent article on Slashdot presents other recording methods if you don't have a FireWire enabled tuner.
Apple FireWire news: soon, more AV/C support! - http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=269141
Macintosh FireWire Software - http://home.comcast.net/~macpvr/