[Amforth] where to save the IP

[Mark M. <m.m...@gm...>]

Hi Matthias!

First of all - thanks to you and all your cohorts for Amforth!  I have been
using Forth for 30 years (F83 ... ) for a variety of projects and Amforth
(since 4.2) with the 328P as my current platform.

A quick question: for timing purposes, I have dropped into assembly
(driving the SPI system as a slave to a Raspberry Pi since the Pi isn't
easy to slave! BTW, the Pi is my ISP too, fun!) I'm trashing the X register
r26 & r27 to index into SRAM - so when I exit my code via 'JMP_ DO_NEXT'
I'm back at the interpeter prompt (surprise!). Where... and how.. is the
safest way to save the IP ... and what else might I be trashing? (I am
using temp0 thru 7 (except for temp5))

My thinking is to use r31:r30 in place of r27:r26 .

Thanks.
Mark Malmros