Help with DECwindows console output

[Ted Lemon]

nigiri% man pm

     RISC                                                             pm(4)

     Name
          pm - monochrome/color bitmap graphics

     Syntax
          device    pm0  at ibus?  vector pmvint

     Description
[...]
          The third minor device provides an access path for console output
          that does not disturb the graphics display.  The caller can open
          the device /dev/xcons.  When this device is open, the graphics
          driver redirects console device output to the input buffer of
          this device.  This mechanism disables console output on the
          screen and saves the output for later display. This preserves the
          graphic display integrity.

          Input and output on the first and third minor devices are pro-
          cessed by the standard line disciplines.
[...]