[NTG-context] width (height?) or 90° rotated tabulate

Good evening all, the following example demonstrates my problem: ··8<····························································· \showframe \newdimen\tabcolsize \tabcolsize=.25\vsize \def\knuth{\input knuth\relax} \startbuffer[sometable] \starttabulate[|p(\tabcolsize)|p(\tabcolsize)|p(\tabcolsize)|p(\tabcolsize)|] \dorecurse{5}{\dorecurse{4}{\NC\knuth}\NC\NR} \stoptabulate \stopbuffer \starttext \placetable[here,split,90]{none}{\getbuffer[sometable]} \stoptext ··8<····························································· As you can see, I need some advice on how to restrain the tabulate float from flowing over into the right margin. What dimension do I need to set and to what value? Thanks for your time Philipp