
Section 3: Automatic Memory Stack and ALPHA Register50



T

0.0000


Z

0.0000


Y

0.0000

(Displayed)

X

78.0000

T

0.0000


Z

0.0000


Y

78.0000

(Displayed)

X

53

T

0.0000


Z

0.0000


Y

0.0000

(Displayed)

X

131.0000



After any calculation or number manipulation, the stack automatically lifts
when a new number is keyed in. Because operations are performed when functions
are pressed, the length of such chain problems is unlimited unless a number
in one of the stack registers exceeds the range of the calculator (up to
9.999999999 × 10^{99}). When the range of the calculator is
exceeded, the HP41C immediately indicates
OUT OF RANGE in the display. Later you
will learn how to instruct the HP41C to ignore these types of overflows.


In addition to the automatic stack lift after a calculation, the stack
automatically drops during calculations involving both the X and Yregisters.
It happened in the above example, but let’s do the problem differently
to see this feature more clearly. For clarity, first press
g
CLX to clear the displayed Xregister. Now, again
solve 21 + 38 + 19 + 53 = ?



T

0.0000


Z

0.0000


Y

0.0000

(Displayed)

X

21 _

T

0.0000


Z

0.0000


Y

21.0000

(Displayed)

X

21.0000

T

0.0000


Z

0.0000


Y

21.0000

(Displayed)

X

38 _

