Artist graphics registers (used in HP9000/712)
==============================================

Artist is the onboard graphics chip used in the HP9000/712. According to
HP, it's mostly compatible to CRX. On the 712, it spans the I/O memory
range 0xf8000000-0xf9ffffff. Unfortunately no documentation seems to be
available, but this is what i figured out by looking at the memory write
from the Bootrom/STI code:

.. list-table::
   :header-rows: 1

   - 
      - Offset
      - Size
      - Description
   - 
      - ``0x1004a0``
      - Word
      - VRAM offset (write index) for write FIFO registers
   - 
      - ``0x1005a0``
      - Word
      - Bitmask for WRAM write FIFO - only bits set both in the data and
        this bitmask will be changed
   - 
      - ``0x100800``
      - Word
      - Block mover source X=Bit31-16 Y=Bit15-0
   - 
      - ``0x100a04``
      - Word
      - Block mover size Width=Bit31-16 Height=Bit15-0
   - 
      - ``0x100600``
      - Word
      - Word mode VRAM write FIFO, with every write the number of X
        pixels is added to the write index.
   - 
      - ``0x100620``
      - Word
      - Byte mode VRAM write FIFO, with every write the number of X
        pixels is added to the write index
   - 
      - ``0x118010``
      - Word
      - foreground color used in block move operations
   - 
      - ``0x118014``
      - Word
      - background color used in block move operations
   - 
      - ``0x30023c``
      - Word
      - Used in selftest code, looks like signature testing result
        register?
   - 
      - ``0x380008``
      - Word
      - Unknown status register, returning 0x20000000 to make STI happy
   - 
      - ``0x380000``
      - Word
      - Unknown status register, returning 0 to make STI happy
   - 
      - ``0x380008``
      - Word
      - Unknown status register, returning 0x20000000 to make STI happy
   - 
      - ``0x0118406c-0x011847ff``
      - Word
      - Color map used by STI code - Strange offset address, maybe
        software configurable? One entry spans 32 bit, where Bit
        23-16=R, Bit16-8=G, Bit7-0=B