User`s guide

Page 9

About Monitor Sensing

Apple’s Monitor Sensing speciﬁcation allows video display

cards to identify the attached monitor. During startup,

Nexus GA checks the status of three of the ﬁfteen pins on the

Apple monitor port. It then auto-conﬁgures itself according to

the monitor sense code detected and enables all resolutions

supported by the monitor. Since Nexus GA relies on this sense

code to correctly auto-conﬁgure during startup, the monitor

must supply the appropriate sense code.

In a case where your monitor does not supply the sense code

information, a display adapter can be used to set the appropriate

sense code for your monitor. Typically, a display adapter is used

to connect a VGA monitor to the Apple monitor port, or to

supply the correct monitor sense code information.

If the display adapter supplies the sense code information for

only one resolution, then only one resolution will be available,

even if the monitor supports multiple resolutions. A resolution

of 640 x 480 is usually the default resolution. Therefore, when

using an adapter to supply the sense code, it must be designed to

supply the proper code for the monitor you are using it with;

otherwise, the Nexus GA card cannot correctly auto-conﬁgure

itself for the attached monitor.

Although the Nexus GA card does not output Sync-on-Green

(SOG) signals, adapters are available to overlay the Composite

Synchronization Signal and send it through the Green video

signal line so that you can use an SOG monitor. Monitors

requiring an SOG signal usually have only three BNC

connectors (RGB).

For more information about obtaining a sense code or

synchronization signal adapter, contact ATI Customer Support

or a computer retailer. For information about how to contact ATI

Customer Support, select the Support button on the ATI

Displays control panel.

NexusGA.BK Page 9 20 November 1997 14:23