(HP71B) ASM question

[floppy]

Question: what is the best method for creating PI in Forth/ASM?
Is there a memory optimized calculation procedure?

In HP71B, apart from using the BASICX command with PI as parameter in a Forth word, its possible to upload a constant; but perhaps not the best memory cautious method.

Comments/remarks are welcome.

Entry points

Code:

=SAVEFP EQU #E717A            save Forth pointer
=STKLFT EQU #E7320            Stacklift Forth OM page 609 pdf
=OX     EQU #2FBD0            X address
=GETFP  EQU #E71A5            restore Forth pointers

PI word

Code:

* PI : put PI into X in the stack. uplift the float stack. lastx not changed (like HP41)
* tested 23Aug2024
       WORD 'PI'
       GOSBVL =SAVEFP
       C=0    S
       P=     0
       LCHEX  314159265359000
       R0=C                  R0 = Result
       GOSBVL =STKLFT
       A=R0
       D0=(5) =OX
       DAT0=A W              Result into X
       GOSBVL =GETFP
       RTNCC