HP HP-20S - Clearing Programs; Editing Programs

Error Stops. If an error occurs while a program is running, program
execution halts at the point the error occurred, and an error message
is displayed. (There is a list of error messages and conditions on page
122.) Press or (€] to clear the display. To see the program line con-
taining the error-causing instruction, press (€] (PRGM].
Clearing Programs
You must be in Program mode (the PRGM annunciator must be on) to
clear programs. Press [¢>] to clear all programs from
memory.
To clear a specific program you must delete each line individually.
Position the pointer at the last line of the program that you want to
delete and press (4] repeatedly. Refer to page 68 for more information
about how to position the pointer.
Editing Programs
You can modify a program by inserting and deleting program lines.
Even if a program line requires only a minor change, you must delete
the old line and insert a new one.
Deleting program lines:
1. Enter Program mode.
2. Position the pointer where you want to begin. (If you are delet-
ing more than one consecutive program line, start with the last
line in the group.)
3. Delete the line you want to change by pressing [¢]. Succeeding
lines are automatically renumbered.
4. To exit Program mode, press (9] (PRGM].
For example, if you want to delete lines 05 through 08, you first dis-
play line 08, then press (4] four times. Subsequent program lines are
moved up and automatically renumbered.
6: Programming 71