Stack algorithm

[Paul Dale]

You need to implement a stack lift flag. Sometimes when you enter a new number you need to raise the stack before putting the value in X, other times you don't. You need a flag to distinguish the two cases. Enter disables stack lift on entry, + enables it.

Of course it is more complex than this.

This is a reside of a decision made in the early 1970's if not before because the calculators then didn't have enough RAM to store the number being entered separately -- instead they used the x register for this purpose.


- Pauli