I used to have a Digidesign-branded expansion chassis (7-slot, SBS) and there was a cable for connecting the chassis to a host card that I found recently. So while finding that and looking at my old inventory, I discovered a similar cable, but not quite. Check the image below:
https://i.imgur.com/wLphONX.jpg
^^^ this cable is identical to the SBS chassis cable, but the one pictured is wider and has more pins (80) as compared to the SBS 7-slot cable (68 I'm guessing).
Does anyone know what this cable is? Maybe it's for a 13-slot SBS chassis, or something simiar.