This update is recommended for all iMac (late 2012) models. This update contains general performance fixes pertaining to sleep and Thunderbolt, and improves compatibility when using the 5GHz band in Wi-Fi.
Boot ROM or SMC Version Information: After Update is complete:
Build version: 010A.05
ROM version: IM131.88Z.010A.B05.1211151146
once I installed the firmware Boot Camp Assistant tells me I need new firmware, my Windows partition no longer shows up as a choice to boot from in Startup Disk or with the Option key at boot time. Installing a new version of Boot Camp Assistan does not help. Boot Camp Assistant seems to be the only way to remove the Windows partition and start over, so I can't start over and I can't fix what I have. This firmware upgrade has completely hosed me, so beware. Oh, but it installed flawlessly for me :(.
This review was originally posted on VersionTracker.com. I thought I was following the directions exactly. HOWEVER, much to my chagrin during the firmware install it tried to eject a CD I had and the lap tray I was using stopped the ejection and the CD was reinserted. THAT is apparently an "interruption" and I ended up with the black screen, won't turn on syndrom forcasted. Go to: