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HP16C logical operations (g shift + the keys in the "lower right corner") - Printable Version

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HP16C logical operations (g shift + the keys in the "lower right corner") - Hsilop - 09-20-2016 03:27 PM

Are the g-shifted logical operations in the "lower right corner" of the keyboard (the 0-3 digits, + and -, decimal point (.) and CHS keys) supposed to produce any result when used outside of a program?

I was expecting them to work on values entered on the stack, but nothing seems to happen in the display. One might expect some value(s) to be popped off the stack, and some new value to be pushed onto it - but that would change the stack which might not be desirable if some later operation (in a program) needs the value(s) in the x (and y) registers.

PS: I should mention that I tried this on a Swiss Micros DM16L, not a HP 16C, but then they should work the same - shouldn't they?


RE: HP16C logical operations (g shift + the keys in the "lower right corner") - hth - 09-20-2016 04:04 PM

They disable stack lift outside a program, that seems to be it.

I could not see any comments about their behavior outside program in the manual and I tried it on a real HP-16C.


RE: HP16C logical operations (g shift + the keys in the "lower right corner") - Didier Lachieze - 09-20-2016 04:10 PM

They have also some effect on the program pointer when executed outside of a program , but they are not intended for that, they are intended to be used inside a program: If comparison is true, program execution continues; if false, program execution skips one line before continuing.


RE: HP16C logical operations (g shift + the keys in the "lower right corner") - damaltor - 09-21-2016 05:53 AM

You guys are right - The Program pointer might be affected, but otherwise the stack is untouched. The operations do NOT disable stack lift though.


RE: HP16C logical operations (g shift + the keys in the "lower right corner") - hth - 09-21-2016 03:05 PM

(09-21-2016 05:53 AM)damaltor Wrote:  You guys are right - The Program pointer might be affected, but otherwise the stack is untouched. The operations do NOT disable stack lift though.

Haha, you are right, I have a tendency to write that opposite... Smile

It ENABLES stack lift.