HP 35s Scientific Calculator - Manual (Page 184)

13-2 Simple Programming
This very simple program assumes that the value for the radius is in the X– register
(the display) when the program starts to run. It computes the area and leaves it in
the X–register.
In RPN mode, to enter this program into program memory, do the following:
Try running this program to find the area of a circle with a radius of 5:
In ALG mode, to enter this program into program memory, do the following:
RPN mode ALG mode
     π
 π
 
Keys:
(In RPN mode)
Display: Description:
 
() Ö () 
Clears memory.
 Activates Program–entry mode
(PRGM annunciator on).
   
Resets program pointer to PRGM
TOP.
   
(Radius) 2
   π
  
Area =
π
x 2
  Exits Program–entry mode.
Keys:
(In RPN mode)
Display: Description:
  
This sets the program to its
beginning.
5  
The answer!
Keys:
(In ALG mode)
Display: Description:
 
() Ö () 
Clears memory.
 Activates Program–entry mode
(PRGM annunciator on).