How to immediately abort a calculation?

[hqvrrsc4]

Well I bought an hp prime several days ago. And I found that... Some integrals/equations will cause the calculator to hang up with a little hourglass icon on the corner of the screen. -This is understandable. But how could I abort the calculation if I don't want it to go on? Now I can only reset the calculator by inserting a paper clip into the reset hole on the back of the calculator. But I don't want to bring a paper clip everywhere with me. Is there any "easier" way achieving this?

Edit: After smashing the keyboard for a while, I found thant hitting "Symb" + "On" will immediately shut down the calculator. But it will clear all history since last boot up. Is there a better solution, which behaviors like hitting "ctrl+C" in matlab(just abort the current calculation and nothing more)?

[DrD]

I presume you updated the firmware to the latest release 8151? You can try holding C-F-O and press on until the prime resets, if on-symb doesn't do it. If things get really crazy, you can reformat the prime from that menu, and exit with a reset (option 9).

[Tim Wessman]

You can try clicking on the ON/C button (cancel when on) several times, or holding it down. That will work in many cases, but sometimes in the CAS it won't work unfortunately.