accessing video cards

[allenb@cs.uoregon.edu]

I am trying to write directly into video memory from lisp.  When I
get the baseaddr from the gdevice record it returns a large negative
number rather than a pointer.  I presume that this is because Lisp
does not recognize 32 bit addresses.  Does anyone know how to coerce 
this number into an address that will allow me to do block moves to
the video card?

Allen Brookes