System 7.5 Update 1.0:Quadra 840AV Updated Display Manager

In the Technical Note for System 7.5 Update 1.0 it reads, "Display Manager update - Quadra 840AV computers did not remember the resolution a multisync monitor was set to between restarts. The monitor would resync as at 640x480 regardless of the value set by the user."

In the System 7.5 Update 1.0 Read Me file it says, "Quadra 840AV: The updated Display Manager ensures that a multi-sync monitor is set to the correct resolution when you restart the computer."

What changed? Customers are calling with questions, because they have installed the System 7.5 Update 1.0 on their Quadra 840AV, and their Multiple Scan monitors do not switch to the higher resolution any sooner.
The change referred to in the Technical Note for System 7.5 Update 1.0 and the Update's Read Me file is a little-known and infrequent problem which occurred in System 7.5. This problem prevented some Macintosh Quadra AV systems from switching to resolutions higher than 640x480 under certain conditions.

After releasing System 7.5, some users reported that their Macintosh Quadra 840AV would sometimes end up with a screen resolution of 640x480 after restarting, instead of the resolution they had chosen before restarting.

As reported in the Technical Note for System 7.5 Update 1.0, it appeared as though the Macintosh Quadra 840AV did not remember the chosen screen resolution. In order to fix this problem, a change was made to the display manager. This change was included in Display Enabler 1.2 and System 7.5 Update 1.0.

Installing System 7.5 Update 1.0 will not allow the Quadra 840AV to switch to a higher screen resolution earlier in the startup process.

The following Tech Info Library article can help you find the Tech Note mentioned here:

Article 24493: "Apple Tech Notes: What They Are, Where To Find Them"
Published Date: Feb 19, 2012