MacOS 9.1 bug: sleep mode and dual monitors (was Re: Dual monitor corruption - help?)

Daniel Barrett wrote on :

I have discovered a MacOS 9.1 bug involving "sleep" mode, dual monitors, and a USB mouse. It kills the display, and is 100% reproducible on my Titanium. Has anyone else seen it? Can anybody else reproduce it? I include a workaround at the end of this message.

  1. Connect an external monitor to the Titanium's VGA output.

  2. Connect an external mouse to the USB port.

  3. While running, close the Titanium lid. The computer goes to sleep.

  4. KEEPING THE COMPUTER LID CLOSED, move the mouse to wake up the computer.

  5. The Mac wakes up. However, the bug occurs:

  • The built-in display stays blank!

  • The external display appears but is corrupted, an approximation of the real thing. You can use the computer but the display doesn't refresh properly.

It looks like Apple didn't think about this case, when the laptop is closed & asleep but woken up by an external mouse movement.

To return the Mac to normal:

  1. Make sure the laptop is open.

  2. Select "Sleep" from the Special menu. Both displays blank as the computer goes to sleep. (This is easier to do if the menu is on the external display, which is visible though corrupted; otherwise you might need to reboot.)

  3. Move the mouse to wake up the machine again. Both displays come up fine.

Can anyone confirm this?

The bug occurs whether you use video mirroring or not, and it doesn't matter which monitor is the startup display or has the menu.


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