On Mon, 29 Oct 2012, Tony Duell wrote:
  I instaleld a version 2 -- the one with the ASIC --
for somebody many
 years ago. It had the conenctors as you describe, and I seem to rememebrs
 a couple of jumpers that you had to set depending on which connector when
 to the controller and which to the drive (the 'manual' confusing referd
 tho it as XT and AT settings, of course the XT-clone I was puttign it in
 had a header plug not a cerd edge on the controller, so it used AT-style
 cabling, which is what confused us for a bit). Anyway, from tracing the
 tracks on the board, ti appeared that these jumpers formed a reversiong
 switch. One signal (perhaps WD?) was intercepted by the board, tjhe
 jumpers swithcd and input and ouptu pin on the ASIC to the correct
 connectors. 
That answers BOTH what the inadequately labelled/documented switch was
for, AND whether it could be installed to the middle of an unbroken floppy
cable (NO.)