The responses to my previous message are appreciated: as a newbie
here, I am reassured by the explanations for the absence of DT and
Screen from the 1.6.1 package binaries.  Evidently the choice between
DT and Screen is largely a matter of taste, but it is very desirable
to be able to do one's own compilation!  For me, this may mean
non-trivial efforts to reclaim enough disk space, which I will ask
about in a separate thread....

-- 
John