Section 10: Program Editing 145

ensures that program execution will branch to line 000 after the program is run.

6.Key in the instruction(s) being added.

7.Key in the instruction that originally immediately followed the point at which the new instruction(s) are being added — that is, the first instruction to be executed after the added instruction(s). (This instruction was replaced by the iinstruction keyed in at step 3.)

8.Press gi followed by three digits that specify the second line following the point at which the new instruction(s) are being added. This i instruction will cause program execution to branch back to the proper line within the original program.

Example: Continuing with the preceding example, suppose incomes less than or equal to $7,500 were not to be taxed. You could modify the program to check for this condition and stop at line 000, displaying the original income keyed in, by storing 7,500 in register R3 and adding the following instructions between lines

000 and 001 (the added lines are the same in RPN and ALG modes): :3~gogi000. Since there are more than four instructions between

(and including) the first line to be executed after the added instructions (line 001) and the last line you keyed into program memory (line 010 in RPN and line 016 in ALG), it will require fewer keystrokes to add the new instructions by branching than to add them by replacement.

Keystrokes (RPN mode)

fs gi.000

gi012

gi.010

gi000

Display

 

 

 

 

Sets calculator to Program mode.

000,

 

Sets calculator to program line

 

 

immediately preceding point at

 

 

which new instructions are being

 

 

added. (In this particular example,

 

 

this step could have been skipped

 

 

since calculator was already set at

 

 

the proper program line.)

001,43,33,012

Branches to program line 012, the

 

 

second line after last line of

 

 

program.

010,

30

Sets calculator to last line of

 

 

program so that the gi000

 

 

instruction keyed in next will be

 

 

stored as the last line of the current

 

 

program.

011,43,33,000

Ends the current program with a

 

 

gi000.

File name: hp 12c pt_user's guide_English_HDPMF123E27

Page: 145 of 275

Printed Date: 2005/8/1

Dimension: 14.8 cm x 21 cm