GRAF(7)             RISC/os Reference Manual              GRAF(7)



NAME
     graf - RS2030 Graphics Display Driver

SYNOPSIS
     #include <sys/grafreg.h>

     graphics display on RS2030

DESCRIPTION
     The graf driver supports output to the RS2030 display using
     a set of shared memory interfaces. The graphics output is a
     frame buffer that is directly memory mapped, such that when
     you write to the memory associated with the display the
     screen is updated with the new pixel.  Currently the display
     is 256 colors (8 bits) or 16 level gray (4 bits).

     The two shared memory id's can be acquired by the following
     example calls:

     buf_id = shmget(GBUFKEY, GRAPHICS_FRAME_SIZE, 0666);
     reg_id = shmget(GREGKEY, GRAPHICS_REG_SIZE, 0666);


     The constant GBFCKEY can be used in place of GBUFKEY if you
     wish to have the graphics memory cached.  Once the id's have
     been acquired the actual shared memory segments can be
     attached to the virtual address space with the following
     example calls:

     buf_addr = shmat(buf_id, GRAPHICS_FRAME_ADDR, 0);
     reg_addr = shmat(reg_id, GRAPHICS_REG_ADDR, 0);

     This setup gets a shared memory segment attached to the
     current process.  Please refer to the MIPS 2030 Technical
     Reference Manual for the actual memory map for the graphics
     board.

     The keyboard driver is used to update the color map so as to
     avoid a screen "tear".

FILES
     /dev/keybd

SEE ALSO
     kbd(7).
     shmget(2), shmop(2) in the Programmer's Reference Manual.









                        Printed 11/19/92                   Page 1