The elusive negative zero on the HP 30b

[rprosperi]

(05-12-2021 07:07 PM)FabioBrasil Wrote:  The SW version is the same: 4 5 2010 ²
Copyright 2048,000 HP Dev. C. L.P (c)
Algebric = 0 (no sign)
RPN = 0 (no sign)
Maybe it's because I use the "," and dd.m.yyyy as the decimal separator and the "."

ENGLISH
TVM STANDARD
ANNUAL
CAL.360
1,23
1.000,00
DEGREE

This has nothing to do with settings, I believe.

But it probably is because you are treating it like classic RPN and doing this:

55555 [+/-] [Input] [shift] [Y^X] => 0.00

While for Entry RPN (used on the 30B) you must do this:

55555 [+/-] [Input] 55555 [+/-] [shift] [Y^X] => -0.00

when using Entry RPN, you must enter a new number into X after pressing Input copies the original X into Y.

For example, if you do this:

5 [Input] [X]

you probably expect an answer of 25.00, but in fact you will get 0.00 (Try it!)

This is because in Entry RPN, the new number in X, after pressing [Input] is 0, so the "5 [Input] [x] is really doing 5 x 0 = 0.00

If you don't regularly use the 20b/30b, this seems odd. To me, this feels more like RPL, which in fact it is copied from.