This routine is an example of an infinite loop. It can be used to collect the initial data. After entering the three values, it is up to you to manually interrupt this loop by pressing label line number to execute other routines.

Conditional Loops (GTO)

When you want to perform an operation until a certain condition is met, but you don't know how many times the loop needs to repeat itself, you can create a loop with a conditional test and a GTO instruction.

For example, the following routine uses a loop to diminish a value A by a constant amount B until the resulting A is less than or equal to B.

Program lines:

Description:

(In RPN mode)

 

  

 

  

 

  

 

  

It is easier to recall A than to remember where it is in the

 

stack.

  

Calculates A – B.

  

Replaces old A with new result.

  

Recalls constant for comparison.

 

Is B < new A?

  

Yes: loops to repeat subtraction.

  

No: displays new A.

 

Checksum and length: 2737 33

Programming Techniques 14-17