PATH ADC Home > Documentation > Hardware > Device Managers and Drivers > PCI Card Services > Designing PCI Cards and Drivers for Power Macintosh Computers

  

---

Display Manager Requirements

The Display Manager needs support from the graphics driver in order to implement the trimming of the available timing modes. In the past, the driver has trimmed these modes depending on the display that was sensed. Now the driver must perform the following functions:

• Report as available (that is, do not trim) all timing modes that are supported by the current graphics card hardware--for example, trim only those modes that require different amounts or configurations of VRAM. When responding to GetNextResolution calls, the driver must return all timing modes supported by the current frame buffer. Do this for DDC displays, multiple scan displays, and single-mode displays.
• If an unknown sense code is found, program the hardware as if a 13- or 14-inch Monitor were sensed.
• If no display is sensed, return an error code from the Initialize or Open routine.
• When responding to GetModeTiming, report as not valid and not safe those timing modes not validated by the sensing algorithm. Do this by clearing the modeValid and modeSafe flags.
• When responding to GetConnectionInfo, perform the extended sense algorithm specified in the next section.
• Support for DDC.