Section 7: Simple Programming114
Running a Program
To run a program you can either execute it using the XEQ key, or you can assign it to a key and execute it by pressing that key in USER mode. Let’s try it both ways. You will find the USER mode operations saves you time and keystrokes.
When you run a program, the HP-41C has two program execution annunciators that appear in the display. As program execution progresses, a   appears in the display. Each time the program executes a program label, the   moves across the display one position to the right. When the   is in the last position on the right of the display, the   resets back to the left of the display.
As an additional aid, the HP-41C also turns on the PRGM annunciator in the display while a program is executing. When the program has completed execution, the PRGM annunciator turns off.
After a program executes an AVIEW or VIEW , the   will not appear, but the PRGM annunciator will be displayed.
These aids provide an indication to you that the calculator is executing a program. You never have any doubt during the execution of a long program; you can easily determine that the calculator is operating.
Take the HP-41C out of PRGM mode now by pressing PRGM . Notice that the PRGM display annunciator turns off.
Keystrokes Display    
PRGM 
  0000    
   
Next, use CIRCLE program you created to find the area of two circles with radii of 14 inches and 0.55 meters:
Keystrokes Display    
14
  14 _    
  The first radius in inches.
XEQ 
  XEQ _ _    
  The HP-41C prompts: Execute what?
ALPHA CIRCLE ALPHA 
  615.7522    
  The answer in square inches.
.55
  .55 _    
  The second radius in meters.
XEQ 
  XEQ _ _    
  The prompt.
ALPHA CIRCLE ALPHA 
  0.9503    
  The answer in square meters.
Now, assign CIRCLE to the LN key location and find the area of two more circles with radii of 10.7 inches and 0.439 meters.