why is RPN always reversed (not PN)

[StephenG1CMZ]

(05-25-2015 06:42 AM)Thomas Radtke Wrote:  In PN, you'd need to have a mixed stack of operators and operands, which ruled this notation out for early calculators imo.

I must be misunderstanding something here...
To me,
1 2 + 3 *
And
* 3 + 2 1
Would both appear to need a stack capable of storing operands or oprerators in a mixed sequence - but only one might generate an error as you enter 3.14i nstead of 3 (depending on the domain of your + and * functions).