The HP 48g series allowed a program to be run automatically when the calculator cold boots—it runs the program in the home directory named STARTUP. I used this feature on my HP 50g to set the KEYTIME variable so that it would not interfere with fast keystrokes, as well as to display a prompt with the current battery level (using a third-party library function).

Can the HP Prime be set up to automatically run a program on a cold boot? If so, what should the program be named?

—DragonLord

The HP Prime is capable of precisely measuring the battery voltage, evident in the diagnostic mode (hold F C O keys while pressing the Reset button). However, the displayed battery meter only specifies battery level in 25% steps.

Is there some function or other means by which I can get the precise battery level or voltage without having to go into the diagnostic mode? Any help would be appreciated.

—DragonLord

Hi! I'm DragonLord, a grad student studying Computer Science. You might know me as a regular on Super User. I've always loved programming and working with computers, but I also happen to like working with calculators. I'm not a huge calculator programmer, but I enjoy using the latest in calculator technology.

I've gone through several different calculators over the years, starting from a TI-84 Plus in middle school (which still works), to a TI-Nspire in high school (the original Clickpad model), to an HP 50g for AP Calculus, to my current HP Prime. I sold my TI-Nspire a while back, but I still have the others. I absolutely love my Prime—that touchscreen is awesome and it's incredibly fast. A while back, I wrote an article on my personal website about benchmarks of the different calculators I've worked with and the HP Prime was by far the fastest of the calculators I tested.

Anyway, it's nice to be a part of the calculator community. Once again, hello!

—DragonLord