Here is a file you can use in the Device Manager for your DR-880.
I do not use my external devices through USB, only MIDI.
In order to receive more help, you will have to provide more detailed information. (Also, in case you are unaware, MIDI and Audio are two different things, and are not really interchangeable.)
On your MIDI Track, is DR-880 (whatever the name says, that represents the DR-880) selected under the routings?
Do you see MIDI activity on the Transport when tapping the pads on the DR-880?
If you open the Key MIDI editor and tap the keys on the vertical keyboard (with the mouse cursor on the MIDI note numbers in the DR-808 manual), can you hear the DR-808 play the corresponding drums?
Please provide screen shots of various screens. The more area the shots cover, the better. Small cut-outs suck, if you want good help. 