All PCRs only have an analog audio out from the factory. The digitial output is a modification done by other people. You don't need the digital out to run the PCR, but it does noticibly help the should quality.
Thanks for the info, just bought one. I guess my next question has to do with how do i get the digital signal into my PC? I found the adapter in either a TOSlink or coax form. But i need to figure out a digital input
Take my advice: Do not try to build a system that includes EVERY feature. Start with the basics, build it to a bug free state, and THEN add on.
Just get a sound card with a digital input. There are a number of products that will meet your need at soundblaster.com If you plan on recording from your XM PCR I would stay away from the USB based ones though, I've had bandwidth problems using these when trying to record and play music at the same time.