WP 34s stack preservation

[signals]

Very impressive!

When I posted the original question, I was wondering why STOS didn't just push the stack into the call stack frame like LocR does so you didn't have to worry about stack size. Obviously, now that you've explained it to me, it is because it wouldn't be available for STO/RCL commands if done that way.

It's clear that an awful lot of thought was put into the design of this calculator, and that it was made by people who actually wanted to use it. I'm sure the HP engineers who created the 35 and its succesors would be very impressed with your work.