HP HP-65 - Page 11

Introduction
The HP-65 can save a number in each of the four registers.
Most problems can be solved by keying in the numbers in the
same order as they appear in the original expression, that is, from
left-to-right. To work a problem, key in the first number. If there
is an operation you can perform at this point, do it. If there is
not, press [ENTER®| . Now key in the next number. Perform any
operation that can be done (+,—,X,—, etc.). If there is no
operation you can perform, [ENTER®] this number and repeat the
procedure, keying in the next number. The following examples
illustrate this procedure.
Arithmetic and the Stack. When you press the addition key the
contents of X and Y are added together. The stack then drops,
with t reproduced in T and Z, z transferred to Y, (y+x) trans-
ferred to X, and x transferred to Last X. (Last X is described in
Section 1.)
Press Contents [ Location
*
+ y \ Y
Last X
The same dropping action takes place with any arithmetic oper-
ator (+,—, X, or=); the result is placed in X.