Section 8: Program Editing133
Keystrokes Display    
SST 
  02 STO 01    
   
SST 
  03 X 2    
   
SST 
  04 PI    
   
SST 
  05 *    
   
SST 
  06 2    
   
SST 
  07 *    
  We will insert a PSE after line 7.
You can see that the HP-41C is now set at line 7 of program memory. If you press a recordable operation now, it will be ‘‘bumped’’ down in program memory.
Thus, to load the PSE instruction so that the program will review the contents of the X-register:
Keystrokes Display    
XEQ 
  08 XEQ _ _    
   
ALPHA PSE ALPHA 
  08 PSE    
  The PSE instruction is now stored
in line 8.
Now let’s see what happened in program memory when you loaded the PSE instruction. With the calculator set to line 7, when you loaded the PSE , program memory was altered ...
  ...from this...    
 
  ...to this.    
 
 
  00    
  00    
     
  01 LBLTAREA     
  01 LBLTAREA     
     
  02 STO 01    
  02 STO 01    
     
  03 X 2    
  03 X 2    
     
  04 PI    
  04 PI    
     
  05 *    
  05 *    
     
  06 2    
  06 2    
     
  07 *     
  07 *     
     
  08 X<>Y     
  08 PSE
The PSE instruction was inserted
  09 RCL 01     
  09 X<>Y    
  here.
  10 *     
  10 RCL 01    
   
  11 PI     
  11 *    
   
  12 *     
  12 PI    
  All subsequent instructions are
  13 2     
  13 *    
  ‘‘bumped’’ down in program
  14 *     
  14 2    
  memory.
  15 +     
  15 *    
   
  16 END     
  16 +    
   
       
  17 END