116  Section 8: Programming Basics 
 
 
File name: HP 12c Pt Converted_user's guide_English_HDP0F123E02_080207  Page: 271 of 281   
Printed Date:  {  2007/8/2Dimension: 14.8 cm x 21 cm 
 
Setting the Calculator to a Particular Program Line 
There will be occasions when you’ll want to set the calculator directly to a 
particular program line — such as when you’re storing a second program in 
program memory or when you’re modifying an existing program. Although you 
can set the calculator to any line by using 
Ç 
as described above, you can do so 
more quickly as follows: 
z   With the calculator in Program mode, pressing gi. followed by three 
digit keys sets the calculator to the program line specified by the digit keys, 
and then displays that line number and the keycode of the instruction stored 
there. 
z   With the calculator in Run mode, pressing gi followed by three digit 
keys sets the calculator to the program line specified by the digit keys. Since 
the calculator is not in Program mode, the line number and keycode are not 
displayed. 
The decimal point is not necessary if the calculator is in Run mode, but it is 
necessary if the calculator is in Program mode. 
For example, assuming the calculator is still in Program mode, you can set it to 
program line 000 as follows: 
Keystrokes Display  
gi.
000 
000, 
Program line 000 
Executing a Program One Line at a Time 
Pressing 
Ç
 repeatedly with the calculator in Program mode (as described earlier) 
enables you to verify that the program you have stored is identical to the program 
you wrote — that is, to verify that you have keyed the instructions in correctly. 
However, this does not ensure that the program you wrote calculates the desired 
results correctly: even programs created by the most experienced programmers 
often do not work correctly when they are first written. 
To help you verify that your program works correctly, you can execute the program 
one line at a time, using the 
Ç
 key. Pressing 
Ç
 while the calculator is in Run 
mode advances the calculator to the next line in program memory, then displays 
that line’s number and the keycode of the instruction stored there, just as in 
Program mode. In Run mode, however, when the 
Ç
 key is released the 
instruction in the program line just displayed is executed and the display then 
shows the result of executing that line. 
For example, to execute the program stored in the calculator one line at a time: