What is the undocumented routine TVRDC?
From a comp.lang.idl-pvwave post by William Thompson: The reason that TVRDC is undocumented is because it’s not needed any more. It doesn’t do anything that CURSOR doesn’t do. TVRDC is only retained for compatibility with older programs. In the old days, before X-windows, CURSOR was used to read coordinates off of line graphics terminals, and TVRDC was used to read coordinates off of image display devices. With the advent of IDL 2.0, the distinctions between different kinds of graphics devices were mostly removed, and both of these functions were merged into CURSOR.
