Rawtyo and cursorpos

[GZ at MIT-MC (Gail Zacharias)]

Not only is cursorpos not always sufficient, it is often unreliable.
For example, contrary to its documentation, (cursorpos 'b) when in column
0 will *NOT* just wrap around to the right margin but move up one line also,
at least on a Teleray.  Same for 'x. (I would assume that accounts for the
rubout-past-continuation-line bug in lisp read functions).  Additionally,
when the previous line was a continuation line ("!" in last column), 
(cursorpos 'b) seems to sometimes move past the !, sometimes not, sometimes
not move at all.  Basically at this point I don't trust (cursorpos) to
do anything for me in the borders of the screen (first/last line/column).