* Disclaimer: I am an employee of Alphabet or one of its subsidiaries, but I do not work on this team, and didn't know anything about it prior to reading this article.
JP-7 has a very high ignition temperature (it was actually used as a coolant/heat sink for the rest of the aircraft), so TEB combusting once it hit the air is used to light the engines.
SR-71s only had a limited amount of TEB to use each flight. I believe it was 13 shots per engine. TEB was used each time the engines were lit and also when afterburners were lit. While the SR-71's routes were built around refueling, the number of TEB shots remaining were the true limiting factor of the SR-71's flight time.
> I always assumed afterburners just meant opening the throttle up but there must be more to it
No, as the name implies it's literally pouring in fuel after the turbine, in the exhaust. The exhaust is hot, yes, but cooler than the combustion chambers (which reside in between the turbine and compressor). So if you have some special fuel that's very hard to ignite then maybe you need some help to get the afterburning started.
Note: I'm not affiliated with Veertu, but I recently came across the product and found it very interesting. If you're interested in OS X's Hypervisor.framework, it was added as part of OS X Yosemite: https://developer.apple.com/library/mac/releasenotes/MacOSX/...
PowerPC Macs (in the 2000s, before the switch to Intel) did indeed require a manual step to update Boot ROM/firmware - a different mechanism than resetting the PRAM. You'd run the installer, then either shut down or reboot the Mac. As it booted, you'd either hold down the power button or the interrupt button (depending on the model) to initiate the update.
