[34S] Complex numbers

[Tugdual]

(03-18-2014 11:22 PM)Massimo Gnerucci Wrote:  

(03-18-2014 10:52 PM)Tugdual Wrote:  A bit puzzled with the choice of using two registers to handle complex numbers. Why did you choose this design? The 15C has two stacks and you use Re<->Im to alternate. Providing that the 34S even has a capability to define the stack size, why didn't you guys use a dual Real/Imaginary stack? Or may be I missed something?

See Complex Calculations under Addressing objects and Appendix F on WP 34S OWNER’S MANUAL.

Thanks for pointing this Massimo. I indeed read "The hardware of the HP-30b does not provide space for different data types. Thus, complex numbers have to be put in two registers each on your WP 34S as described on p. 29.".

Still I don't understand. If I'm not mistaken the 30b is essentially a microcontroller which at best brings BCD hardware support. I would imagine that the stack is essentially a matter of coding a table and a pointer and there must be enough space since we do have the possibility to double the stack size (which I don't use because above 4 registers is beyond my brain limits). Also regarding types, we do have the flexibility to calculate with 34 digits so why not twice 16 digits for complex numbers.

I'm certain there are good reasons for this limitation but I don't understand how the hardware impacts this.