The layout of the data of a Bob's image is different from that of a
VSprite because of the way the system retrieves data to draw Bobs.
VSprite images are organized in a way convenient to the Sprite hardware;
Bob images are set up for easy blitter manipulation.  The imagedata
pointer is still initialized to point to the first word of the image
definition.

    Note:
    -----
    As with all image data, a Bob's imagedata must be in chip memory
    for access by the blitter.

The sample image below shows the same image defined as a VSprite in the
"using virtual sprites" section above.  the data here, however, is laid
out for a Bob.  The shape is 2 planes deep and is triangular:


            <first bitplane data>

  mem        1111 1111 1111 1111    Least significant bit of sprite line 1
  mem + 1    0011 1100 0011 1100    Least significant bit of sprite line 2
  mem + 2    0000 1100 0011 0000    Least significant bit of sprite line 3
  mem + 3    0000 0010 0100 0000    Least significant bit of sprite line 4
  mem + 4    0000 0001 1000 0000    Least significant bit of sprite line 5

            <second bitplane data>

  mem + 5    1111 1111 1111 1111    Most significant bit of sprite line 1
  mem + 6    0011 0000 0000 1100    Most significant bit of sprite line 2
  mem + 7    0000 1111 1111 0000    Most significant bit of sprite line 3
  mem + 8    0000 0011 1100 0000    Most significant bit of sprite line 4
  mem + 9    0000 0001 1000 0000    Most significant bit of sprite line 5

            <more bitplanes of data if Bob is deeper>