


      METHEUS(7)                 (Bull-SPS9)                 METHEUS(7)



      NAME
           metheus - Bull-SPS9-supported color display


      DESCRIPTION
           /dev/metheus refers to a device driver for a Metheus Omega
           440 display controller connected to the Bull-SPS9 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
           Bull-SPS9 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 read(2), write(2), and
           ioctl(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 stdio(3S) routines,
           data will be buffered in the application.  Care must be
           taken to flush the output to achieve proper graphical
           effects.

           The following ioctl(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.





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      METHEUS(7)                 (Bull-SPS9)                 METHEUS(7)



      DEVICE CODE
                                        block-type orstandard
               device type      major   minor       character-typefile name

               metheus   7      0..n    character   /dev/metheus


      FILES
           /drivers/metheus  /dev/metheus


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









































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