You do not need to load the advanced terrain dll like that...at least, I do not. (I use DBPro 1.063, but I think that has been the case for awhile now.)
You did not load the texture and detail images...here. This is still really messy, and does not work very well, but...please continue. I would suggest using the values that the sample you are using provides for tiling, scaling, etc. until you get a more workable bit of code up and running. It is difficult to get anywhere when all you get is a black screen, isn't it? I will go ahead and tell you that you should get a skybox in there
Rem Created: 11/3/2006 7:07:36 PM
Rem ***** Main Source File *****
rem load dll "AdvancedTerrain.dll",1
global land as integer = 1
sync on : sync rate 0 : hide mouse : backdrop off
SET DIR "data"
bump$="heightmap.bmp"
land$="texture.bmp"
detail$ = "detail.tga"
load image detail$, 1
load image land$, 2
MAKE OBJECT terrain land
set terrain heightmap land,bump$
set terrain scale land, 1,2,3
value=5
set terrain split land,value
set terrain tiling land,value*6
set terrain light land, 1,0.5,0.75, 1, 1, 1, 1
set terrain texture land, 1, 2
build terrain land
set camera range 0, 0.5, 5000 rem There is more to camera setup.
do
rem Do something here....
update terrain land
sync
loop
That should get you going anyway.