24-Bit Color Graphics Board Memory Mapping

[Jeff Rodriguez]

I would like to bypass SunView and the Pixrect library and write directly
to the CG8 24-bit color graphics board.  I am running SunOS 4.1 on a
SPARCstation 1+ with a CG8 board from RasterOps Corp.  The SunOS 4.1 man
page on "cgeight" provides the following.

    When using the mmap system call to map in the cgeight frame
    buffer, the device looks like:
      DACBASE: 0x200000  Brooktree Ramdac     16 bytes
               0x202000  P4 Register          4 bytes
      OVLBASE: 0x210000  Overlay Plane        1152 x 900 x 1
               0x230000  Overlay Enable Plane 1152 x 900 x 1
               0x250000  24-bit Frame Buffer  1152 x 900 x 32

Chapter 5 of the Sun manual on "Writing Device Drivers" talks about using
mmap to write directly to the frame buffer.  I have tried this
unsuccessfully.

1.  Has anybody tried writing directly to the 24-bit graphics board?
2.  How do you use mmap properly?
3.  Where can I get documentation on the Brooktree Ramdac?
4.  Where can I get documentation on the P4 register?
5.  Where is the storage for the gamma-correction colormap
    and for color1, color2, and color3, which are used by the
    overlay planes?

If you know any of the pieces to this puzzle, please let me know!  Send
e-mail to "rodriguez at ecevax.ece.arizona.edu" or post.

			Thanks,

			Jeff Rodriguez
			rodriguez at ecevax.ece.arizona.edu