Only points in common are the radio and a laptop without serial ports.
I use RT Systems w/ their USB cable to program the 880. I have the same software and cables for other radios and they all work well together.
I made a data cable from information on the net and have used it with DRATS. It uses a serial 9 pin connector seems to work OK.
I use Edgeport's Inside Out USB converters. I agree that the converters depending on chip sets, drivers and your OS can be a problem. I am using XP Home SP3 on a HP DV1000 laptop and the combination has played well with all the different radios I have had connected. The Edgeport is a premium priced device and this one is a 4 port with 25 pin connectors. I also have a 2 port with 9 pin connectors.
Recently the operation system on the laptop got screwed up so I decided to reformat and reload. Something I was dreading especially making sure I had a good driver install for the Edgeport. The converter is key to using the PC for radio operations. It went much better than expected! The operating system was able to find the driver I needed on the net. So if you find a working Edgeport without the driver, it seems the company has put it on the net for access.
I hope that helps.
The road goes on forever and the party never ends...