Well... My 850 came with a 9 pole to 25 pole serial cable... Would a "regular" 9 to 9 pole serial cable work? Or would it be preferable to get a 25-to-9 pole adapter? Personally, I'd prefer the "straight" route without adapters, but if the cabling of the 850 serial cable is "special", that won't work of course.
Calling... I'm located in Europe, calling might be pretty expensive, so if there's a different way to get a power supply for the 50, I'd be very interested :-)