Here's a progress report. The +5v power supply is made and seems top work. The connections have all been made on the Rio circuit board- no shorts. However, upon powering up the Rio with everything attached, the Rio's main power supply died. I never got a chance to test the digital out, because the failure was instantaneous. The fuse is still good. It bothers me that the Rio's power supply is so fault intolerant. Haven't had any luck finding what part went bad. I hate switching power supplies!

Anyway, I ordered two replacement supplies and will try to see what caused the other one to die. So far no real clues.

Stu