HP HP-67 User Manual

62 The Automatic Memory Stack
Chain Arithmetic
You’ve already learned how to key numbers into the calculator and
perform calculations with them. In each case you first needed to
position the numbers in the stack manually using the key.
However, the stack also performs many movements automatically.
These automatic movements add to its computing efficiency and ease
of use, and it is these movements that automatically store intermediate
results. The stack automatically ‘‘lifts’’ every calculated number in
the stack when a new number is keyed in because it knows that after
it completes a calculation, any new digits you key in are a part
of a new number. Also, the stack automatically ‘‘drops’’ when you
perform a two-number operation.
To see how it works, let’s solve
16 +30 +11 +17 =7
If you press first, you will begin with zeros in all the stack
registers, as in the example below, but of course, you can also do the
calculation without first clearing the stack.
Remember, too, that you can always monitor the contents of the stack
at any time by using the £l operation.
Press Stack Contents
16 T 0.00
Z 0.00 16 is keyed into the
Y 0.00 displayed X-register.
X 16.
T 0.00
z .
Y 3:20 16 is copied into Y.
X 16.00
30 T 0.00
Z 000 30 writes over the 16 in X.
Y 16.00
X 30.

HP HP-67 Specifications

General

Brand	HP
Model	HP-67
Category	Calculator
Language	English