Adding Instructions By Replacement - HP 12C Platinum Owner's Handbook Manual

112 Section 10: Program Editing
To add instructions within a program, you could simply key in the new
instructions, beginning at the proper program line, followed by the original
instructions from that program line through the end of the program. This method
is described below under Adding Instructions by Replacement. When
instructions must be added in the middle of a long program, however, using this
method will require you to key in numerous instructions – namely, the original
instructions from the point at which the new instructions are added through the
end of program memory. Since keying in these instructions may require a
significant amount of time, in such situations you may prefer to use the method
described below under Adding Instructions by Branching.
That method basically involves branching to the new instructions which are
stored at the end of program memory, then branching back to the program line
immediately following the line from which you branched out. Adding instruc-
tions by branching is not so simple as adding instructions by replacement; how-
ever, it generally will require fewer keystrokes whenever there are more than
four program lines between (and including) the first line to be executed after the
new instruction(s) and the last line you keyed into program memory. Further-
more, if program memory includes branches to program lines following the point
at which the new instruction(s) are being added, adding instructions by branch-
ing will not require that you change the line numbers specified in the i
instructions, which may be necessary when you add instructions by replacement.

Adding Instructions by Replacement

1. Press fs to set the calculator to Program mode.
2. Press gi. followed by three digits that specify the last program line
to be executed before the added instruction(s). This sets the calculator to
the proper program line for adding the new instruction(s) in the next step.
3. Key in the new instruction or instructions.
4. Key in the original instruction or instructions, beginning with the first
instruction to be executed after the added instruction(s), and continuing
through the last instruction you keyed into program memory.
Note: If program memory includes branches to program lines following
that at which the first new instruction is being added, remember to change
the line number(s) specified in the i instruction(s) – as described above
under Changing the Instruction in a Program Line – to the actual new line
number(s).
Example: Assuming you have added a - instruction at the end of program
memory as in the preceding example, suppose you now wanted to insert an t
instruction before the - instruction so that the program will display the amount
of the tax before displaying the net income after tax. Since there is only one