old brother machine advice needed

I have an old brother machine (585) which still works fine. Also have
an attched ribber (586) However have lost the manual for the ribber
and need a bit of help using it. how do i set it for circular/tubular?
there are three sliders on it, one on the botton edge that goes from P
to R and to on the carriage, both go from N to P-R. predumably i set
ot on half pitch and then make the knit carrige knit on one direction
(push in part button?) and the ribber carriage in the other but what
combination of the sliders will do that.

thanks in advance.