Casio fx-7400G PLUS User manual

Programming
1. Before Programming
2. Programming Examples
3. Debugging a Program
4. Calculating the Number of Bytes Used by a Program
5. Secret Function
6. Searching for a File
7. Editing Program Contents
8. Deleting a Program
9. Useful Program Commands
10. Command Reference
11. Text Display
12. Using Calculator Functions in Programs
Chapter
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Chapter 8 Programming
1. Before Programming
The programming function helps to make complex, often-repeated calculations quick
and easy. Commands and calculations are executed sequentially, just like the manual
calculation multistatements. Multiple programs can be stored under file names for
easy recall and editing.
Select the PRGM icon in the Main Menu and enter the PRGM Mode. When you do,
a program list appears on the display.
Selected memory area
(use
f and c to move)
1(EXE) ........ Execute program
2(EDIT) ....... Program edit
3(NEW) ...... New program
[
1(DEL) ........ Specific program delete
2(DEL•A) .... Delete all
3(SRC) ....... File name search
Press [to return to the previous menu.
•If there are not programs stored in memory when you enter the PRGM Mode, the
message “No Programs” appears on the display and only the NEW item (3) is
shown in the function menu.
File Name
Program
File Name
Program
File Name
Program
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A
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2. Programming Examples
Example 1To calculate the surface area and volume of three regular
octahedrons of the dimensions shown in the table below
Store the calculation formula under the file name OCTA.
Length of One Side (A) Surface Area (S) Volume (V)
7 cm cm2cm3
10 cm cm2cm3
15 cm cm2cm3
The following are the formulas used for calculating surface area S and volume V of a
regular octahedron for which the length of one side is known.
2
S = 2 3 A2,V= –––– A3
3
When inputting a new formula, you first register the file name and then input the
actual program.
uu
uu
uTo register a file name
Example To register the file name OCTA
•Note that a file name can be up to eight characters long.
1. While the program list is on the display, press 3(NEW).
3(NEW)
3(Q).......... Password registration
4(SYBL) ...... Symbol menu
2. Input the name of the file.
OCTA
•The cursor changes form to indicate alpha character input.
•The following are the characters you can use in a file name:
A through Z, spaces, [, ], {, }, ’, ”, ~, 0 through 9, ., +, –, ×, ÷

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Chapter 8 Programming
•Pressing 4(SYBL) displays a menu of symbols that can be input.
4(SYBL)
•You can delete a character while inputting a file name by moving the cursor to the
character you want to delete and pressing D.
3. Press wto register the file name and change to the program input screen.
w
•Registering a file name uses 17 bytes of memory.
•The file name input screen remains on the display if you press wwithout input-
ting a file name.
•To exit the file name input screen and return to the program list without register-
ing a file name, press Q.
uu
uu
uTo input a program
Use the program input screen to input the contents of a program.
1(TOP) ........ Top of program
2(BTM) ....... Bottom of program
3(MENU) .... Mode menu
•Pressing [displays a menu of symbols that can be input into a program.
[
[
Press [to return to the previous menu.
1234
File name
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Programming Chapter 8
uu
uu
uTo change modes in a program
•Pressing 3(MENU) while the program input screen is on the display causes a
mode change menu to appear. You can use this menu to input mode changes into
your programs. For details on each of these modes, see “Using the Main Menu”, as
well as the sections of this manual that describe what you can do in each mode.
3(MENU)
•Pressing !Zdisplays a menu of commands that can be used to change set
up screen settings inside a program. For details on each of these commands, see
“To change a mode set up”.
!Z
[
[
[
[
[
Actual program contents are identical to manual calculations. The following shows
how the calculation of the surface area and volume of a regular octahedron would be
calculated using a manual calculation.
Surface Area S ... c*!9d* <value of A> xw
Volume V ............ !9c/d* <value of A> Mdw
You could also perform this calculation by assigning the value for the length of one
side to variable A.
Length of One Side A
............. <value of A> aaAw
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Surface Area S ... c*!9d*aAxw
Volume V ............ !9c/d*aAMdw
If you simply input the manual calculations shown above however, the calculator
would execute them from beginning to end, without stopping. The following com-
mands make it possible to interrupt a calculation for input of values and display of
intermediate results.
?: This command pauses program execution and displays a question mark as a
prompt for input of a value to assign to a variable. The syntax for this command
is: ? →<variable name>.
^^
^^
^:This command pauses program execution and displays the last calculation re-
sult obtained or text. It is similar to pressing win a manual calculation.
•For full details on using these and other commands, see “Useful Program Com-
mands”.
The following shows examples of how to actually use the ? and ^commands.
!W[1(?)aaA[3(:)
c*!9d*aAx
[[2(^)
!9c/d*aAMd
QQ
uu
uu
uTo run a program
1. While the program list is on the display, use fand cto highlight the name of
the program you want to run.
2. Press 1(EXE) or wto run the program.
Let’s try running the program we input above.
Length of One Side (A) Surface Area (S) Volume (V)
7 cm 169.7409791 cm
2
161.6917506 cm
3
10 cm 346.4101615 cm
2
471.4045208 cm
3
15 cm 779.4228634 cm
2
1590.990258 cm
3
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Programming Chapter 8
1(EXE) or w
hw
(Value of A)
Intermediate result produced by ^
w
w
baw
w
•Pressing wwhile the program’s final result is on the display re-executes the
program.
•You can also run a program while in the RUN Mode by inputting:
Prog ”<file name>” w.
•An error (Go ERROR) occurs if the program specified by Prog ”<file name>”
cannot be found.
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3. Debugging a Program
A problem in a program that keeps the program from running correctly is called a
“bug,” and the process of eliminating such problems is called “debugging.” Either of
the following symptoms indicates that your program contains bugs and that debug-
ging is required.
•Error messages appearing when the program is run
•Results that are not within your expectations
uu
uu
uTo eliminate bugs that cause error messages
An error message, like the one shown below, appears whenever something illegal
occurs during program execution.
When such a message appears, press dor eto display the location where the
error was generated, along with the cursor. Check the “Error Message Table” for
steps you should take to correct the situation.
•Note that pressing dor ewill not display the location of the error if the pro-
gram is password protected.
uu
uu
uTo eliminate bugs that cause bad results
If your program produces results that are not what you normally expect, check the
contents of the program and make necessary changes. See “Editing Program Con-
tents” for details on how to change program contents.
4. Calculating the Number of Bytes Used
by a Program
This unit comes with 20,000 bytes of memory. A byte is a unit of memory that can be
used for storage of data.
There are two types of commands: 1-byte commands and 2-byte commands.
• Examples of 1-byte commands: sin, cos, tan, log, (, ), A, B, C, 1, 2, etc.
• Examples of 2-byte commands: Lbl 1, Goto 2, etc.
While the cursor is located inside of a program, each press of dor ecauses the
cursor to move one byte.
•You can check how much memory has been used and how much remains at any
time by selecting the MEM icon in the Main Menu and entering the MEM Mode.
See “Memory Status (MEM)” for details.
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5. Secret Function
When inputting a program, you can protect it with a password that limits access to
the program contents to those who know the password. Password protected pro-
grams can be executed by anyone without inputting the password.
uu
uu
uTo register a password
Example To create a program file under the name AREA and protect it with
the password CASIO
1. While the program list is on the display, press 3(NEW) and input the file name
of the new program file.
3(NEW)
AREA
2. Press 3(Q) and then input the password.
3(Q)
CASIO
•The password input procedure is identical to that used for file name input.
3. Press wto register the file name and password. Now you can input the contents
of the program file.
•Registration of a password uses 16 bytes of memory.
•Pressing wwithout inputting a password registers the file name only, without a
password.
4. After inputting the program, press Qto exit the program file and return to the
program list. Files that are password protected are indicated by an asterisk to the
right of the file name.
Q
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uu
uu
uTo recall a program
ExampleTo recall the file named AREA which is protected by the
password CASIO
1. In the program list, use fand cto move the highlighting to the name of the
program you want to recall.
2. Press 2(EDIT).
2(EDIT)
3. Input the password and press wto recall the program.
•The message “Mismatch” appears if you input the wrong password.
6. Searching for a File
You can search for a specific file name using any of the three following methods.
•Scroll Search — scroll through the file names in the program list.
•File Name Search — input the name of the file.
•Initial Character Search — input the first few letters of the name of the file.
uu
uu
uTo find a file using scroll search
Example To use scroll search to recall the program named OCTA
1. While the program list is on the display, use fand cto scroll through the list
of program names until you find the one you want.
2. When the highlighting is located at the name of the file you want, press 2(EDIT)
to recall it.
2(EDIT)
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