Section 8: Program Editing139
DEL never deletes more lines than you have in a program (providing the program is terminated with an END ) and never deletes more lines than there are allocated to program memory.
Correcting Instructions
You can also use    to correct keystroke errors while you are keying in instructions of your programs. In fact,    works just the same in PRGM mode as it does when you are working problems and keying in numbers and ALPHAs in normal mode.
When you make an error while you are keying in a program instruction, simply press    in PRGM mode. Your last keystroke will be deleted.
For example, set the calculator back to line 14 and insert a PSE instruction (notice the keystroke error):
Keystrokes Display    
PRGM 
  00 REG 38    
  Sets the HP-41C to PRGM mode.
g GTO · 014 
  14 *    
   
XEQ 
  15 XEQ _ _    
   
ALPHA PSF 
  15 PSF _    
  Whoops, this should be PSE, not PSF. When you make an error simply press    .
   
  15 PS _    
  Now you can key in the correct letter, E.
E 
  15 PSE _    
   
ALPHA 
  15 PSE    
  The PSE is now in line 15.
PRGM 
  1,483.8370    
  Result remains from example on
 
       
  page 137.
Run the program using a height of 56 inches and a radius of 12 inches.
Keystrokes Display    
56 ENTER  
  56.0000    
   
12 
  12 _    
   
AREA ( LOG ) 
  4,222.3005    
  Intermediate answer.
 
  5,127.0792    
 
g CLX  014 
  0.0000    
   
USER 
  0.0000