\simplecolumns have served me well. However, it seems a bit shy to respond to \setupcolumns (although in file page-mul.tex the definition of \setupcolumns preceeds that of \startsimplecolumns).
For example, the following typesets 2 columns instead of 4; to set 4 columns \startsimplecolumns[4] is required.
\starttext
\setupcolumns[n=4]
\startsimplecolumns
\input tufte
\stopsimplecolumns
\stoptext

Can someone tell me if \setupcolumns has any effect on the typesetting of simplecolumns? 
Which parameters of those on \setupcolumns are effective in simplecolumns? Not all do, as for example rule=on seems to have no effect.

Hans van der Meer