Section 7

Program Editing

There are many reasons to modify a program after you've already stored it: you might want to add or delete an instruction (like O, ©, or ¦), or you might even find some errors! The HP-15C is equipped with several editing features to make this process as easy as possible.

The Mechanics

Making a program modification of any kind involves two steps: moving to the proper line (the location of the needed change) and making the deletion(s) and/or insertion(s).

Moving to a Line in Program Memory

The Go To (t) Instruction. The sequence t“nnn will move program memory to line number nnn, whether pressed in Run mode or Program mode (PRGM displayed). This is not a programmable sequence; it is for manually finding a specific position in program memory. The line number must be a three-digit number satisfying 000 ≤ nnn ≤ 448.

The Single Step (Â) Instruction. To move only one line at a time forward through program memory, press  (single step). This function is not programmable.

In Program mode: Â will move the memory position forward one line and display that instruction. The instruction is not executed. If you hold the key down, the calculator will continuously scroll through the lines in program memory.

In Run mode: Â will display the current program line while the key is held down. When the key is released, the current instruction is executed, the result displayed, and the calculator steps forward to the next program line to be executed.

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