[This followup was posted to alt.comp.periphs.videocards.ati and a copy
was sent to the cited author.]
I've got a ATI AIW 8500 card. It only allows 125 channels.
DirectV has lots of channel above that I can't watch with
this card. Anyone has a recommendation for a better card or
a solution?
They are two different things. The built-in tuner of your card only
does ANALOG signals on a cable system. Only 125 are defined (and these
days, the highest used is typically 75-78). The rest are used for
digital channels, modems, etc, depending on the available bandwidth on
the cable system. Digital channel numbers (at least on a cable box or TV
with CableCard installed) are assigned electronically, and don't conform
to any universal standard. They can and do change the frequency
occasionally. Comcast is moving toward digital simulcasting of the
analog channels. Digital and analog channels are being moved around and
even deleted to make room.
Your DirectTV is totally different. It's a satellite system, and
requires a SATELLITE tuner to pick up the digital signals. Everything is
highly compressed, and channel numbers really have no relation to actual
frequency. Like digital cable channels, numbers are assigned for human
convenience, not by frequency.
To get your DirectTV into your computer, you must be using either RF
(typically channel 3 or 4), or video inputs. This means the satellite
box has to do the tuning.