iMac firmware update

[Robert Seltman]

If you have a 27" iMac and do the two recent firmware updates, be ready for a roller coaster experience as your computer does its thing. Here is how Apple describes the steps in a way of warning.

This update fixes Target Display Mode compatibility issues on 27-inch iMac computers.

When your computer restarts a gray screen will appear with a status bar to indicate the progress of the update. Your Computer's fans will run at full speed during the update but will return to normal speed once the update completes. Do not disturb or shut off the power on your iMac during this update.