Why must we buy Peavey's Legacy BOB cable instead of using a ots serial cable.  I don't have a problem buying them, I just am curious about the difference.

The terminations of our cable are much better.  The communciation rate is much, much higher on these cables than would ever be expected on a standard serial cable (more like CAT5, which is why we changed the cable to CAT5 with the 8802 BoBs).
Scott