To see the line in the program containing the error–causing instruction, press { e. The program will have stopped at that point. (For instance, it might be a instruction, which caused an illegal division by zero.)

Editing a Program

You can modify a program in program memory by inserting, deleting, and editing program lines. If a program line contains an equation, you can edit the equation — if any other program line requires even a minor change, you must delete the old line and insert a new one.

To delete a program line:

1.Select the relevant program or routine ( {Vlabel), activate program entry ( {e), and press šor ™to locate the program line that must be changed. Hold the cursor key down to continue scrolling. (If you know the line number you want, pressing {Vlabel nnnn moves the program pointer there.)

2.Delete the line you want to change — if it contains an equation, press { c{}; otherwise, press b. The pointer then moves to the preceding line. (If you are deleting more than one consecutive program line, start with the last line in the group.)

3.Key in the new instruction, if any. This replaces the one you deleted.

4.Exit program entry ( ‡or {e).

To insert a program line:

1.Locate and display the program line that is before the spot where you would like to insert a line.

2.Key in the new instruction; it is inserted after the currently displayed line.

For example, if you wanted to insert a new line between lines A0004 and A0005 of a program, you would first display line A0004, then key in the instruction or instructions. Subsequent program lines, starting with the original line A0005, are moved down and renumbered accordingly.

To edit an equation in a program line:

1.Locate and display the program line containing the equation.

12–18Simple Programming