Do you know of a more low-level solution for when when my system is frozen, and the keystroke to open terminal (and run htop or "killall APPNAME") doesn't do anything?
ctrl+alt+f7 to go back to desktop
For a kernel panic or lockup I think it's a combination roughly similar to:
1. Ctr-Alt-PrintScreen
2. continue to hold Alt
3. R-I-S-U-B as a sequence, to make certain things happen and like syncing the file system