CG14 Pixel Modes for Running the Window System

The cgfourteen frame buffer is configurable to scan out either 8-bit pixels or 32-bit pixels. This allows the cgfourteen to be used in high resolution modes. For example, you can configure a 4MByte cgfourteen connected to a multi-sync monitor to display 8-bit pixels at 1280x1024 resolution with the command:

When the system is rebooted the monitor displays at the new resolution. Since 4MBytes is insufficient memory to have 32 bits per pixel, invoking OpenWindows will automatically select 8-bit pixels only.

The same hardware, when configured to display at 1152x900 resolution with the command:

will allow OpenWindows to use 32 bits per pixel, after rebooting.

In both modes, the left-over VRAM not displayed on the screen is utilized by the window system for pixmap allocation.

It is possible to use the frame buffer in 8-bit pixel mode even when there is sufficient VRAM for 32-bit pixels. There is a significant performance improvement when the frame buffer is in 8-bit pixel mode. To force the pixel mode, put the verb pixelmode="8" in the OWconfig file used by the server. The OWconfig file is typically in /usr/openwin/server/etc.

A complete entry with this in the file would look like: