NAME
        SetChipRev -- turns on the features of a Chip Set  (V39)

   SYNOPSIS
        chiprevbits = SetChipRev(ChipRev)
                                   d0

        ULONG SetChipRev(ULONG);

   FUNCTION
        Enables the features of the requested Chip Set if available,
        and updates the graphics database accordingly.

   INPUTS
        ChipRev - Chip Rev that you would like to be enabled.

   RESULT
        chiprevbits - Actual bits set in GfxBase->ChipRevBits0.

   NOTES
        This routine should only be called once. It will be called by the system
        in the startup-sequence, but is included in the autodocs for authors
        of bootblock-games that wish to take advantage of post-ECS features.

   SEE ALSO
        <graphics/gfxbase.h>