On Tue, Oct 13, 2015 at 04:39:32AM -0800, Dave Higton wrote: > On Tue, 13 Oct 2015 13:09:27 +0100 George Greenfield wrote: > > > I must confess to having used Ctrl-Break from time to time, when faced > > with a frozen desktop, without evident ill-effects. Is it considered > > worse than powering-off at the switch, which is the only other option > > AFAIK? > > Probably, although I'm not really qualified to answer.
You can assume the following simplification: Alt-Break allows you to force a stuck task to call Wimp_CloseDown, essentially causing it to quit. Note that this forced quit isn't clean: any open files will remain so, and any memory allocated via dynamic areas or the RMA will be leaked. Ctrl-Break essentially calls OS_Reset, which causes a software reset that for all but the very most obscure situations is functionally identical to pressing the hardware reset button. The danger with Ctrl-Break and the hardware reset button is that FileCore might be trying to do something at the time (or be struck trying), leaving the file system in an unclean state, requiring the use of something like Disknight to fix. Summary: Always try Alt-Break first (and the a clean shutdown straight after), and only Ctrl-Break/Hardware reset button as a last resort. B.