HP 33s hp 33s_user's manual_English_E_HDPM20PIE56.pdf - Page 179

The Checksum, To clear all programs from memory

Page 179 highlights

To clear all programs from memory: 1. Press { e to display program lines (PRGM annunciator on). 2. Press { c {} to clear program memory. 3. The message prompts you for confirmation. Press {&}. 4. Press { e to cancel program entry. Clearing all of memory ({ c {}) also clears all programs. The Checksum The checksum is a unique hexadecimal value given to each program label and its associated lines (until the next label). This number is useful for comparison with a known checksum for an existing program that you have keyed into program memory. If the known checksum and the one shown by your calculator are the same, then you have correctly entered all the lines of the program. To see your checksum: 1. Press { Y {} for the catalog of program labels. 2. Display the appropriate label by using the cursor keys, if necessary. 3. Press and hold |  to display /checksum and /length. For example, to see the checksum for the current program (the "cylinder" program): Keys: (In RPN mode) Display: Description: { Y hold)   /  Displays label C, which takes 67 bytes. Checksum and length. If your checksum does not match this number, then you have not entered this program correctly. You will see that all of the application programs provided in chapters 15 through 17 include checksum values with each labeled routine so that you can verify the accuracy of your program entry. In addition, each equation in a program has a checksum. See "To enter an equation in a program line" earlier in this chapter. Simple Programming 12-21

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Simple Programming
12–21
To clear all programs from memory:
1.
Press
to display program lines (
PRGM
annunciator on).
2.
Press
{
} to clear program memory.
3.
The message
prompts you for confirmation. Press {
}.
4.
Press
to cancel program entry.
Clearing all of memory (
{
}) also clears all programs.
The Checksum
The
checksum
is a unique hexadecimal value given to each program label and its
associated lines (until the next label). This number is useful for comparison with a
known checksum for an existing program that you have keyed into program
memory. If the known checksum and the one shown by your calculator are the
same, then you have correctly entered all the lines of the program. To see your
checksum:
1.
Press
{
} for the catalog of program labels.
2.
Display the appropriate label by using the cursor keys, if necessary.
3.
Press and hold
to display
checksum and
length
.
For example, to see the checksum for the current program (the "cylinder"
program):
Keys:
(In RPN mode)
Display:
Description:
{
}
Displays label C, which
takes 67 bytes.
(hold)
Checksum and length.
If your checksum does
not
match this number, then you have not entered this
program correctly.
You will see that all of the application programs provided in chapters 15 through
17 include checksum values with each labeled routine so that you can verify the
accuracy of your program entry.
In addition, each equation in a program has a checksum. See "To enter an
equation in a program line" earlier in this chapter.