HP 50g questions

[DavidM]

(03-23-2019 09:52 AM)Lode Wrote:  2. In RPN mode, you are required to hold down shift and F keys at the same time to use the graph functions rather than first shift then F key. Why is this, and why only in RPN? It's a bit of an unintuitive and painful key combination to execute.

I don't possess any inside documentation about this, but I suspect that it stems from previous precedents that were already set for left- and right-shifted F1-F6 keys in RPN mode. Specifically, left-shift F1 (or F2, F3...) will store whatever is in stack level 1 into the global variable whose name appears above that key in the main menu. Similarly, right-shift F1 (etc.) will recall the contents of the named global variable designated by that key to the stack. Since those functions were already defined, shift-hold functions were probably used as an alternative when those graphic functions were added.

(03-23-2019 09:52 AM)Lode Wrote:  3. Is there any way to visually see if there is a next menu for the "nxt" button at the horizongal buttom menu row (without trying by actually pressing "nxt")?

No built-in way, but it would be possible for a "System Outer Loop" replacement to implement such a feature. Perhaps someone knows if that type of function has already been created in a third-party app. Anyone know if this has already been implemented in an app or library?

(03-23-2019 09:52 AM)Lode Wrote:  4. If I would download a program that has "erf" and "erfc" functions (or program them), is there any way that you can then add these erf and erfc in the built-in "special functions" menu or can custom functions only go in different menus?

Thanks

If what you mean by "special functions" menu is the one that results when you press the APPS key, it's possible to do that with a customized library. If what you mean is the "CUSTOM" menu (which places items in the menu area of the display above the F1-F6 keys), that can be done very easily by storing appropriate items in a list variable named 'CST'. Once that variable has been created, activate the menu with the CUSTOM command (left-shift MODE).