Device Descriptions

HP Series 700 Integrated Graphics

The HP Series 700 Integrated Graphics Workstations (see the section "Supported Graphics Devices" in Chapter 1) support three different versions of integrated graphics.

High Resolution Grayscale

These displays have 1280x1024 pixels with a single bank of eight planes for 256 shades of gray. There is no offscreen memory in the frame buffer. They are 8-plane single-buffered devices. These grayscale devices are similar to the grayscale GRX, but there is not an extra 8-plane bank for double-buffering.

The only X server mode supported is image mode with 8 planes, single-buffered. For information on supported X server modes, read the section "Supported X Server Modes" in Chapter 1 “Introduction and Device Comparison”.

High Resolution Color

This display has 1280x1024 pixels with a single bank of 8 color planes for 256 colors. It has a color map that provides 8 bits per color (for red, green and blue components). This yields a color palette of over 16 million colors. There is no offscreen memory in the frame buffer. The HP 705, 710, 715, and 725 color are 8-plane single-buffered devices. These color models are very similar to the CRX, but there is not an extra 8-plane bank for double-buffering.

Medium Resolution Color

This display has a resolution of 1024x768 pixels. In all other respects, it is the same as the HP 710 color display.

Grayscale GRX

This display has 1280x1024 pixels with two banks of eight planes. Its color map provides eight bits for a total of 256 values of gray. There is no offscreen memory in the frame buffer.

The GRX device is an 8-plane, double-buffered grayscale version of the CRX. It provides the same level of performance as the color CRX in a grayscale configuration; the GRX only supports a grayscale monitor.

The software to handle grayscale actually resides in the higher level Starbase code, not the driver. It is designed so that color applications can run without modification using the closest matching shades of gray. Application optimization for grayscale is encouraged, but not necessary. All the Starbase color map modes (CMAP_NORMAL, CMAP_FULL and CMAP_MONOTONIC) are supported on the grayscale configurations.

The only X server mode supported is image mode with eight planes, double-buffered. For information on supported X server modes, read the section "Supported X Server Modes" in Chapter 1 “Introduction and Device Comparison”.

Starbase echos are stored in the opposite bank from the bank being rendered to. This can cause some anomalies in echo appearance.

If the GRX is used primarily for Starbase graphics applications in X, it is recommended that the SB_X_SHARED_CMAP environment variable be set to true. (See the Color Map Sharing Starbase and X Windows section). If the primary usage of the GRX is X applications that do not use Starbase, then do not set the SB_X_SHARED_CMAP environment variable.

Color CRX

This display has 1280x1024 pixels with two banks of eight color planes each for 256 colors. Its color map provides eight bits per color (for red, green and blue components). This yields a color palette of over 16 million colors. There is no offscreen memory in the frame buffer.

The CRX device supports 8/8 double-buffering. It is similar to the PersonalVRX except that the CRX does not have overlay planes, and each window can display a bank independently of other windows. Another term for this second feature is per-window double-buffering.

The CRX device has some differences due to its color map hardware support in CMAP_FULL mode. See the section on color in this chapter.

Starbase echos are stored in the opposite bank from the bank being rendered to. This can cause some anomalies in echo appearance.

If the CRX is used primarily for Starbase graphics applications in X, we recommend that you set the SB_X_SHARED_CMAP environment variable to true. (See the Color Map Sharing Starbase and X Windows section). If the primary usage of the CRX is X applications that do not use Starbase, then do not set the SB_X_SHARED_CMAP environment variable.

CRX-24

The CRX-24 device has 24-image planes and 8-overlay planes. The screen resolution is 1280x1024 pixels. There is no offscreen memory in the frame buffer. This graphics display board is only supported on the Series 700 workstations.

You can configure the image planes in three basic ways:

8-bit indexed color (CMAP_NORMAL, CMAP_MONOTONIC), 8/8 double-buffered
12-bit direct color (CMAP_FULL), 12/12 double-buffered
24-bit direct color (CMAP_FULL), single-buffered

You can select each of the three configurations on a per-window basis. The configuration selected is a function of the depth of the window created and double-buffer mode.

In the 8-bit indexed configuration, each pixel is used as an index into a 256-entry color map. Each entry in the color map provides eight bits per color (for red, green and blue components) providing a color palette of over 16 million colors. Double-buffering is achieved by switching between two banks of 8-bit indexes. You can perform 3:3:2 direct color emulation in this mode but the driver performs much slower than either 12-plane direct color or 24-plane direct color mode. The PowerShade software adds support for dithering, shading and Z-buffering.

In the 12-bit direct color configuration, each pixel is represented by four bits per color channel to allow for double-buffering. One buffer resides in the upper planes and the other buffer resides in the lower planes of each color channel. Dithering improves the color resolution.

In the 24-bit direct color configuration, a pixel is represented by eight bits each per color channel. Double-buffering is not possible in this mode.

The overlay planes are mainly for use by the X server. Rendering to overlay planes must be done using the hpvmx or the sox11 drivers. The hpgcrx driver will not render to overlay planes.

The X server works only in combined mode. For information on supported X server modes, read the section "Supported X Server Modes" in Chapter 1 “Introduction and Device Comparison”.

There are four different hardware color maps available for use with the image planes. This reduces color flashing effects that occur when shifting the color map focus from window to window. This phenomenon is sometimes referred to as the technicolor effect. One of these four color maps will be dedicated for use by direct color graphics windows. The other three will be shared by all indexed color graphics processes.

Because the CRX-24 supports multiple color maps, there is less need for color map sharing between X and Starbase so the SB_X_SHARED_CMAP environment variable is ignored.

CRX-24Z

The CRX-24Z is an optional accelerator that attaches to the CRX-24 device to provide high performance 3D solids modeling and high performance 3D wireframe with anti-aliasing. The CRX-24Z accelerator has a dedicated 24-bit Z-buffer. The CRX-24Z board attaches to the CRX-24 device directly, and does not require a separate SGC slot. The hpgcrx driver automatically uses the CRX-24Z accelerator if it is present. The primary use of the CRX-24Z accelerator is for 3D solids modeling, including drawing Starbase polygons, rectangles, triangle strips, quadrilateral meshes, and spline surfaces.

The CRX-24Z device is a high-speed scan converter that accelerates rendering into the CRX-24 frame buffer. The CRX-24Z accelerator can render to the 24 image planes on the CRX-24 in 8-bit indexed (CMAP_NORMAL), 12-bit direct color (CMAP_FULL), and 24-bit direct color (CMAP_FULL). The CRX-24Z accelerator does not support rendering to the CRX-24 overlay planes. If the CRX-24 overlay planes are specified in a gopen call, the CRX-24Z accelerator will not be enabled.

Optimized 3D Shaded Polygon Performance

The CRX-24 (with PowerShade) and CRX-24Z provide optimal 3D shaded polygon performance. Shaded polygons on the CRX-24 and CRX-24Z are highly optimized and very fast in most cases. See 〈starbase〉^[11]/PERF_NOTES in the on-line PowerShade performance notes for a detailed list of features and performance data. This data is subject to change without notice.

Dual CRX

The Dual CRX device has two color CRX displays on a single board which fits into a single expansion slot. Each display has 1280x1024 pixels with two banks of eight color planes for 256 colors. The Dual CRX is supported on the Series 700 only.

Each of the two devices on a Dual CRX requires its own device special file to access it. Mixing a Dual CRX display with any other display in the same SPU is not supported. Two Dual CRX displays are supported in the same SPU, for a total of four graphics displays.

The only X server mode supported is image mode with 8 planes, double-buffered. For information on supported X server modes, read the section "Supported X Server Modes" in Chapter 1 “Introduction and Device Comparison”.

Each display behaves the same as a single color CRX with the following exceptions:

There is no device file shipped for the second display. The system is originally shipped with 〈dev〉^[12]/crt only. You must create the second device file using the mknod command.
The 〈x11-admin〉/X0screens file must be modified to run an X server which uses both displays.

Running two X servers, one on each display of the Dual CRX, is not supported. A single keyboard and pointing device are associated with the X server, whether the server runs on one, two, three or all four displays.

Supported Dual Head Configurations

The HP-UX 10.0 revision supports the following dual heads on the Series 700:

Model 720: One Dual CRX, provides two CRX heads.
Model 730: One Dual CRX, provides two CRX heads.
Model 750: Two CRX-24 heads, each requires a separate SGC slot.
Model 750: One or two Dual CRX, provides a two or four head CRX workstation.

PowerShade, 3D Surfaces Software

PowerShade is an optional software package that supports lighting and shading in graphics design. It has capabilities for both surface rendering and volumetric rendering, the latter on the CRX-24 and CRX-24Z only. The PowerShade software is included with the CRX-24Z graphics device (not standalone), and is an option for the CRX, Dual CRX, CRX-24 and the color versions of the integrated graphics systems (HP 705/710/715/725). It is not supported on the GRX or the grayscale version of the integrated graphics systems (HP 705/710/715/725).

In order to use the HP VMX driver with PowerShade from any graphics system, you must install the PowerShade software. For more information on HP VMX, read the chapter "HP VMX Device Driver."

^[11]The actual path names of directories in angle brackets depend on the file system structure. See the Graphics Administration Guide for details.

^[12]The actual path names of directories in angle brackets depend on the file system structure. See the Graphics Administration Guide for details.