HDTV questions


I have some questions about HDTV. Every individual at best buy, circuit city, and soundtrack gives a totally seperate answer, and magzines seem to skip over alot of this stuff.

I live in colorado, Comcast is our digital cable company, and they are now advertising HDTV with thier service.

1) If you have a dish or cable company that sends an HDTV signal, to you need to buy a HD decoder to see HD? Or do the cable boxes do the decoding?

2) Do you need an HDTV to use progressive scan?

3) What types of inputs are requred for progressive scan? the RGB? or does Svider work as well?
slappy
The difference between HDTV and HDTV-ready is weather or not the TV has an on-board HD decoder right?

Without the decoder you use the cablebox as a decoder?
On some HD tv's you can delete unwanted inputs. This you would use to cycle between the 2 inputs in use versus having to switch thru the 6 or seven total provided on many tv's..Tom