HP HP-65 - 3. Creating Your Own Program

3. Creating Your Own Program
Programmability and Definable Keys
Highly sophisticated calculations can be achieved by sequences
of keystrokes. Since the calculator is truly programmable, in-
cluding both branching and testing capability, it is quite possible
to set a program to iterate all night. Programs can consist of up
to 100 memory locations.
We have seen how the top row key functions can be defined to a
particular use by loading an appropriately prerecorded magnetic
card. Using a very simple example, we will now define the £}
key. We first plan the function, key it into memory, and then
test it. If it tests satisfactorily, we will record it on a magnetic
card for future use.
Planning the Function
The following key sequence computes x* (the cube of whatever
value k is in the X register).
T
z
k
Y k| k k
k
X k k? k8
Key ¢+ ¢+ X x
Note: ENTER4 is here
abbreviated as ¢ .
To adapt the sequence to be a function that is callable by the
key, we precede the sequence by B (c0 identify the func-
tion) and conclude the sequence by (to return control to
the keyboard).