This keyword switches-on PGPLOT's support for ReGIS graphics, making it possible to see GraphEnt's graphics from a whole series of ReGIS-capable VT terminals (eg VT125, VT240, VT241, VT330, VT330+, VT340, ...). To make things go faster (especially if you are calculating a Patterson function), consider adding a GRAMaxContours keyword, and increasing the value of GRACycles. You may also want to define the GRAWait keyword. Enjoy (and don't let anyone touch your VTs).