


      MMMMEEEETTTTHHHHEEEEUUUUSSSS((((7777))))                   ((((RRRRiiiiddddggggeeee))))                   MMMMEEEETTTTHHHHEEEEUUUUSSSS((((7777))))



      NNNNAAAAMMMMEEEE
           metheus - Ridge-supported color display


      DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
           ////ddddeeeevvvv////mmmmeeeetttthhhheeeeuuuussss refers to a device driver for a Metheus Omega
           440 display controller connected to the Ridge via the DR-11
           compatible parallel interface.

           The hardware parallel interface closely resembles the
           popular DR-11W Direct Memory Interface.  The driver provides
           machine-specific support for DMA transfers between the Ridge
           and the Metheus color display system.  I/O functions include
           writing commands and accompanying parameter values from user
           programs to the color display system, reading response data
           from the color display system into the user's data buffers,
           and issuing ioctl directives to control the device.

           If the application uses the basic _r_e_a_d(2), _w_r_i_t_e(2), and
           _i_o_c_t_l(2) system calls, the data will not be buffered.
           Instead, each write request will be sent to the device as an
           immediate DMA transfer.  DMA write transfers are started,
           and control is returned to the application, possibly before
           the transfer completes.  Thus a new buffer of data can be
           generated and a second write issued while the transfer
           completes.  Because of this write-ahead feature, an error
           may be returned for a write that really applies to the
           previous write request.

           Each read should be issued for the correct number of bytes
           the device will return, which usually depends on the
           commands encoded in a prior write.  Each ioctl is executed
           immediately by the driver.

           If the application uses the buffered _s_t_d_i_o(3) routines, data
           will be buffered in the application.  Care must be taken to
           flush the output to achieve proper graphical effects.

           The following _i_o_c_t_l(2) call is available:

                #include <sys/dr11io.h>
                ioctl(fd, command, arg);
                int fd, command, arg;

           The only defined value for "command" is:

           DR11RESET1:  Perform a cold (hard) reset of the graphics
           controller.


      DDDDEEEEVVVVIIIICCCCEEEE CCCCOOOODDDDEEEE
                                        _b_l_o_c_k-_t_y_p_e _o_r_s_t_a_n_d_a_r_d



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      MMMMEEEETTTTHHHHEEEEUUUUSSSS((((7777))))                   ((((RRRRiiiiddddggggeeee))))                   MMMMEEEETTTTHHHHEEEEUUUUSSSS((((7777))))



               _d_e_v_i_c_e _t_y_p_e      _m_a_j_o_r   _m_i_n_o_r       _c_h_a_r_a_c_t_e_r_-_t_y_p_e_f_i_l_e _n_a_m_e

               metheus   7      0..n    character   /dev/metheus


      FFFFIIIILLLLEEEESSSS
           /drivers/metheus  /dev/metheus


      SSSSEEEEEEEE AAAALLLLSSSSOOOO
           The Metheus Omega 400 manuals for details on the byte
           sequences to control the color display.











































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