CGTHREE(4)            OpenBSD Programmer's Manual (SPARC)           CGTHREE(4)

NAME
     cgthree - 8-bit color frame buffer

SYNOPSIS
     cgthree* at sbus?
     cgthree* at obio0 (some sun4m models)
     wsdisplay* at cgthree?

DESCRIPTION
     The cgthree is a color frame buffer, available as an SBus card or on-
     board on some sun4c and sun4m workstations.  A small number of frame
     buffer SBus cards, not manufactured by Sun, are cgthree-compatible and
     will also be recognized by the cgthree driver.

     The cgthree driver interfaces the frame buffer with the wscons(4) console
     framework.  It does not provide direct device driver entry points but
     makes its functions available via the internal wsdisplay(4) interface.

DISPLAY RESOLUTION
   Sun frame buffers
     If the cgthree frame buffer is used as the console display, it is possi-
     ble, for some models, to select a different resolution than the default
     1152x900 or 1024x768 by changing the OpenPROM environment.  To change the
     default resolution, type the following:

       ok setenv output-device screen:r1152x900x66

     to change to a 66Hz 1152x900 resolution.

     If the cgthree frame buffer is a secondary display, or a serial console
     is used, the display resolution can not be changed without using an
     nvramrc OpenPROM script.  Refer to the Sun Frame Buffer FAQ for details.

     The cgthree frame buffer accepts the following resolutions:

     screen:r1024x768x77   Super VGA 1024x768, with a refresh rate of 77Hz.
                           This is the default setting on model 501-2691.
     screen:r1152x900x66   Standard 1152x900, with a refresh rate of 66Hz.
                           This is the default setting on older models
                           (501-1415 and 501-8044).
     screen:r1152x900x76   Standard 1152x900, with a refresh rate of 76Hz.
                           This is the default setting on more recent models
                           (501-1718 and 501-1909).

     Note that not all models support settings other than their default set-
     ting.

   Tritec GVC-1, Integrix SFB200
     These frame buffers are cgthree-compatible cards with a VGA-compatible
     video connector.  There are only two resolutions supported, selected by
     jumper JP2 on the card:

     JP2      Resolution

     open     1024x768, 60Hz
     short    1152x900, 66Hz

SEE ALSO
     intro(4), sbus(4), wscons(4), wsdisplay(4)

     Sun Frame Buffer FAQ, http://www.sunhelp.org/faq/FrameBuffer.html.

OpenBSD 4.7                     March 31, 2008                               1
