Specifications

CHAPTER 1
Overview of the AppleVision 1710AV and 1710 Displays
18 New Display Connections Specifications
■ Do not trim invalid functional sResources. If your video card does not have a
programmable ROM, you will need to put the trimmed sResources back in when you
patch your driver. These timing modes may be enabled by the display.
■ Trim duplicate timings. If your card has different functional sResources with the same
timing, you should trim all but one of the functional sResources for each timing mode.
■ Trim functional sResources that your hardware cannot support. For example, if your
video card does not have enough VRAM to support a functional sResource, trim that
sResource rather than marking it invalid. The timing mode represented by that
sResource is not one you would want the display to enable.
■ Implement cscGetConnection and cscGetModeTiming for all timing modes. You
should mark any timing mode that is not supported by the sense code as invalid and
unsafe. When you do this, the display may override the decision.
■ Allow the display to switch to invalid timing modes. Some invalid timing modes may
be validated by the display, and you should allow the switch, even though you may
be unaware of their validity.
■ If you do not recognize a sense code, mark all timing modes invalid, and program the
hardware with the Apple 13” timing modes. This allows a smart display to come in as
an unknown timing mode and enable the modes it supports.
Be particularly alert to the following situations:
■ Some drivers use the kAllModesValid or kAllModesSafe calls from
scsGetConnection, rather than implementing cscGetModeTiming for all timings.
If you add a group of invalid modes, you should not mark them as valid in the
cscGetConnection call.
■ If your video card is intended to work on systems that were released before the
Display Manager was introduced, you need to check for the Display Manager before
enabling invalid timings. Otherwise, the user will see the invalid timings in the
Monitors control panel.
■ If your video card supports additional standard timings that do not have constants in
Video.h, contact Apple Developer Support.