from Bill Sommerfeld <sommerfeld@orchard.arlington.ma.us>:

> bah.  it has on-line help available, in the form of

> !man ed

Problem is that where ed is likely to be used is when booting installation 
kernel using diskettes, CD or possibly DOSBOOT, and then vi and man are not
available.  So the user types ed (file name including path), sees a number and
cursor on the following line, and is really in the dark.