VRX Device-Dependent Information

Supported Visuals

The following visuals are supported:

None of these visuals support DBE or MBX double-buffering.

In image mode the default visual is the Depth 8 PseudoColor visual. In overlay mode it is the depth 3 or depth 4 PseudoColor visual as specified by the device file. In combined mode the first device file specifies the default visual. Examples are shown in the section below.

VRX Device Files

Different device files exist for the image planes and overlay planes on VRX devices. The X server supports three different modes of operation on VRX devices: image, overlay or combined.

In image mode, the X server runs only in the image planes. This is the default on VRX devices. To operate in image mode, the image device file should be specified as the primary screen device. For example:

/dev/crt                        # Image mode

In overlay mode, the X server runs only in the overlay planes. Since only 3 or 4 planes are available in the overlay planes on VRX devices, the number of colors is very limited. To operate in overlay mode, the overlay device file should be specified as the primary screen device. For example:

/dev/ocrt                  # Overlay mode using 3 overlay planes
    or
/dev/o4crt                 # Overlay mode using 4 overlay planes

In combined mode, the X server runs in both image and overlay planes. To configure the X server to operate in combined mode, a primary and a secondary device must be specified. The VRXSecondaryDevice is used for this purpose. For example:

/dev/ocrt /dev/crt       # default visual lives in overlay planes
    or
/dev/crt  /dev/ocrt      # default visual lives in image planes