Xdigit

[PoKung Lin]

Hi Ken,
	To uncomment any code under function display_backdrop() does not
make the raster display work. There are basically two version of this
function. Each part of the code are commented separately. With you and
other people's responses now I believed that this part of the functionality
of xdigit is still under the developement.

	Thank you for all the people response to my question.

	PK Lin
	E-mail: pklin at cerf.net
	Tel: (617) 942-1655