>I'm working on a game and I've got a problem.
>Now, the game is in 128 colors + 128 shaded 
>colors. The last bitplane is for shading...
>Now, the bitmap is 768 pixels wide. I don't
>need the shaded bitmap to be that wide, that's
>my problem. I would like that last bitplane to
>be just 320*256 pixels.. Now setting this up
>aint a problem with CludgeBitmap but how do
>I show this darn thing? I want to be able
>to scroll the first 7 bitplanes leaving the
>last still..

There are no simple Blitz2-functions for it. However it's not impossible
though. You'll have to alter the CopList. If you want to scroll up, then
there's no problem at all. Just alter the BPLPTHx and BPLPTLx with 40 bytes
and the pictures starts to scroll. But scrolling one bitplane to the left
or right  isn't really possible on the Amiga hardware :(  The BPLPTH and 
BPLPTL can be set in number of bytes. This won't give you verry smooth
scrolling results. Therefore there are two scrolling registers. These registers
allow you to change the display offset by 16 bits. This way the screen seems
to scroll smoothly. This is the same technique as used on the good old CMB64.
But as I already said, there are only two scrolling registers. One for the EVEN
and one for the ODD bitplanes. So if you want to scroll bitplanes 1,3 and 5,
bitplane#7 moves along with the scroll, and starts to bounce left to right.
This is why Dual-playfield only uses only ODD or EVEN bitplanes for a playfield