Here's what I want to do:
- Rip out the CDRW and add in the 80GB drive.

If you just want to replace the factory drive, you don't have to remove the CDRW. It is in theory possible to bring Central up on a blank drive by booting from the supplied reinstall CD. This procedure will, I expect, void your warranty.

You can't use two drives in a Rio Central; the software doesn't look for a second drive; it probably refuses to start if the CD drive isn't available; and there's only one IDE channel.

I don't see any discussion concerning HOW to access the Linux OS externally on the Rio Central.. can I just plug it into the COM port like my empeg and type 'q'?

Consumer units don't have serial ports. But you can just plug in a USB keyboard and press Ctrl-Alt-Del. It brings up a shell on console.

Peter