CASIO 9750G User Manual

Connecting the PICAXE 08M and PICAXE 18X

to the Casio 9750G Plus graphics calculator

Introduction to Casio BASIC

Compiled from various web resources

July 2008 © Michael Fenton

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Casio BASIC

PART 1: Creating a Program

To create a new program press then locate the program icon, press , press to create a new program. You will then be asked to enter a name for

your program, also you may create a password at this time (WARNING: if you put a password on your program you will not be able to use the debugger).

PART 2: Variable Basics

A variable is something which holds a value. The most commonly used are the

letters A~Z and r,_. There are others, but they are not covered in this section. To

store a value into a variable you must use the key, like this:

CODE

1->A // Assigns 1 to A

It should look like this:

CODE

1->A~D // Assigns 1 to A B C & D

Variables are the most important aspect of programming.

PART 3: Basic Loops

Loops are used to repeat blocks of code. There are several types of loops in Casio

BASIC: Goto/Lbl, Do/lpWhle, For/Next, and While/WhileEnd. Here is an example of

a Goto/Lbl loop:

CODE

1->A //Assigns 1 to A

Lbl 1

A+1->A //Adds 1 to the variable A and stores new value

Goto 1 //Returns to Lbl 1

This loop will execute infinitely, Adding 1 to A each time (actually it will stop when

the value of A is greater than 99*10^99 because you will get a mem error).

Here is an example of a For loop; note that it does not take as many lines:

CODE

For 1->A to 100 Step 1

//this loop assigns 1 to A then adds 1 to A until it equals 100

Next //Goes back to the start of the loop, adds the step to the

variable.

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Anything between the For and next statement will be executed until the expression

evaluates true (A equals 100). By changing the value of Step you can change how

much A is incremented by.

The While loop checks to see if the expression is true then executes the code. After

the code has been executed it returns to the top, checks the expression, and if it is

false jumps out of the loop and continues with executing the program. This is an

example of a While loop.

CODE

1->A

While 1=1 //1 always equals 1 so the expression always evaluates to

True

A+1->A

WhileEnd

Since the while loop evaluates the expression before executing the code it is

possible that if the expression is false before loop begins (ex: 1=2) then the loop

will never occur, it will just skip right over the code and continue with the program.

Unlike a while loop a Do/LpWhle loop will always execute at least once since it

evaluates the expression after the code has been executed. A Do/LpWhle loop looks

like this.

CODE

1->A

Do //Start of the Do/LpWhle loop

A+1->A

LpWhle A<100 //Loops while A is less than 100

PART 4: Selection Statements

Selection Statements are used to make programs have differing outcomes, instead

to executing the same way every time they are run. A selection statement checks

an expression, sees if it is True or False, then if True executes the rest of the

statement otherwise it skips to below the statement and continues with execution.

There are two types of selection statements on the calculator. They are the If/Else

statement and the => arrow.

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An If/Else statement works like this

CODE

1->A

If A=1 //expression to be evaluated

Then “HI” //result if expression is true

“HOW ARE YOU”

Else “BYE” //result if expression is false

“SEE YOU LATER”

If End //end of statement

Result:

Since A is 1 the statement evaluates to true, therefore

QUOTE (Program Output)

HOW ARE YOU

is printed. If you replaced the first line with 0->A then the if statement would

evaluate to False, and

QUOTE (Program output)

BYE

SEE YOU LATER

would be printed.

An If statement can contain many different things, and can be many lines long,

they are the keystone to making a game, and before going on you should feel

comfortable using them.

The => arrow is also very useful, it is a single line selection statement that takes

up less space but can do less than a normal if/else.

This is the same code as above, except using the => arrow instead of the If

statement.

CODE

1->A

A=1=>”HI”

A=1=>“HOW ARE YOU”

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A<>1=>”BYE” // <> means not equal to

A<>1=>”SEE YOU LATER”

In general, the best time to use a if statement is when you have at least two lines of code to be put inside, otherwise use the => arrow.

PART 5: Advanced Loops

Nesting is when you take one loop and put it inside another. Here is an example:

CODE

0->C

For 1->A To 10 //Step can be omitted instead of using Step 1

For 1->B To 10

A+B+C->C

C // the represents the output sign, it displays whatever is

before it and Pauses until [EXE] is pressed.

By executing this code you will get this output:

QUOTE (Program Output)

1100 //caused by

Now we will go through the code and look at what each line does.

Line 1: 0->C

Assigns the value 0 to the variable C

Line 2: For 1->A To 10

Tells the program that you will be looping until A is equal to 10, adding 1 with each

loop.

Line 3: For 1->B To 10

Tells the program that you will be looping until B is equal to 10, adding 1 with each

loop.

Line 4: A+B+C->C

The current value in A will be added to the current value of B, that value is then

added to the current value of C and then assigned to C.

Line 5: Next

Goes to line 3.

Line 6: Next

Goes to line 2.

Line 7: C

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Displays the final value of C.

As you can see, the second loop executes completely for each iteration (loop) of the

first loop.

Nesting also applies to selection statements, you can nest if or => inside each

other as needed.

Example:

CODE

A<1=>A>0=>”HI”

If A<1

Then if A>0

Then “HI”

End If

Part 6: Logical Operators

As you have just seen, there are times when you will want more than one condition

in a selection or loop, you can nest the statements or you can use a logical

operator: AND OR, NOT.

AND and OR are operators which can be used in selection statements to specify

additional conditions, therefore the code above could be written:

CODE

A<1 and A>0=>”HI”

Instead of:

CODE

A<1=>A>0=>”HI”

The OR operator allows you to specify alternate conditions which are evaluated

independently and if any are true then the entire statement is considered true. This

means you can do this:

CODE

If A=1 Or B=1

Then “TRUE”

End If

When this executes it will print TRUE if A or B equals 1.

The NOT operator can also be used in selection statements, though it is not used

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