
Section 3: Automatic Memory Stack and ALPHA Register46


Try it now:




Notice that whenever you move numbers in the stack using one of the data
manipulation functions the actual stack registers maintain their positions.
Only the contents of the registers are shifted. Later, in
section 6, you will
learn how to exchange the Xregister with any other storage register in the
HP41C.


The ENTER Key


When you key numbers into the calculator, you must tell the calculator when
you have finished keying in one number and are ready to key in the next
number. You do this using the ENTER key.


In addition to letting the calculator know you are finished keying in a number,
pressing ENTER also moves the number into the stack.
Here is what happens when you key in a number and press
ENTER :




First, when you key in the number, the stack is changed...


...from this...

...to this.

4.0000


3.0000

3.0000

1.0000

1.0000

2.0000

2.0000

987.3000

Then, when you press ENTER , the number is pushed into
the Yregister. The contents of the stack are then changed...

...from this...

...to this.

3.0000


1.0000

1.0000

2.0000

2.0000

987.3000

987.3000

987.3000



The value in the Xregister is duplicated and pushed into the Yregister.
the numbers in Y and Z are pushed up to Z end T, respectively, and the number
in T is lost off the top of the stack.
