>> NetBSD's curses isn't drawing in the lower-right corner,
>> to avoid scrolling, probably done by shifting a character into the corner.
> 
> Yes.  This is historical behaviour of our curses library.  It's probably
> sensible to remove this now.  Any terminals that can't handle it could
> have a capability added to their termcap entry.

Even if it's unsafe to draw in the bottom left corner (due to risk of
unwanted scrolling), one should be able to adjust the background colour
by positioning the cursor there and then using clear-to-end-of-line or
clear-to-end-of-screen (assuming the terminal has the back_color_erase
capability).

--apb (Alan Barrett)