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This page is designed to give someone with no programming experience an insight into the TI-89's version of TI-Basic.

For other versions of TI-BASIC, See TI-Basic Programming.

Introduction[]

Purpose[]

The purpose of this section of the TI-Basic Wikibook is to explore the capabilities of the TI-89 series (TI-89/Titanium, TI-92/+, Voyage 200) with the built-in interpreter. It is recommended to read through the guide from the beginning in order to build a strong understanding of the language and its applications. This section is devoted entirely to the Motorola 68k version of TI-Basic, which is more powerful than the Z80 version. For information on TI-Basic for the Z80 series, return to TI-Basic Programming and select the TI-84 version.

Overview[]

TI-Basic is a simple interpreted language used on Texas Instruments graphing calculators, which can be used to rapidly automate equations or algorithms. However, as an interpreted language, it is generally not fast enough for a game, so for anything requiring fast processing, assembly language is required. This is, however, outside the scope of this Wikibook. Even though the language is slow, for most purposes it will serve admirably.

Differences between Versions of TI-Basic[]

  • The version of TI-Basic for the 83-type calculators (73 Explorer, 83/+/SE, 84/+/SE) is less powerful, and also less integrated into the calculator itself. However, it is still powerful enough to automate most functions.
  • The version for the 89-series (89/Titanium, 92/+, Voyage 200), is more powerful and more heavily integrated into the calculator. For this section of the TI-Basic Wikibook, this is the version that will be focused upon.

Output[]

How to display words, numbers and more to the user

Disp[]

Disp, I/O(F3):2, is a command which will display a number, string, equation or other type of variable/literal given as arguments. Disp can accept an unlimited number of arguments separated by commas (although it recommended to keep the number of arguments under 7 because after seven, for each consecutive argument the screen pushes everything else up passed the top of the screen, even the seventh pushes the first line up a slight amount), and will display each argument following the previous line.

Syntax: Disp[]

:Disp [arg][,arg2][,arg3][,arg4][,…argN]
  • Where arg,arg2,arg3,arg4 and all other arguments through argN are optional parameters. The number of arguments is only limited by the calculator memory. The arguments can be either a literal or variable of any type.
  • For each argument, Disp displays the argument on the next line, starting from where the the cursor initially was located. If the display reaches the seventh line, the display will 'scroll' the rest of the screen up so that the argument can be displayed.
  • Disp displays all arguments left-aligned
    • if what is being displayed contains more than 26 characters string will "run off the screen", resulting in a display of only a part of the 27th character and none of the ones beyond that being shown.
  • If no argument is specified, the command does nothing.

Disp 5+7

Ex: Display Lines[]

Assuming you have stored the value 5 into x (via 5→x) and a blank I/O screen and you executed this program,

:Disp "HELLO WORLD",52,x+1


you would have the following on your I/O screen:

HELLO WORLD
52
6


Ex: Empty Lines[]

:Disp "","","HELLO WORLD"




HELLO WORLD


Ex: Truncated[]

:Disp "This line too long for one line"


This line too long for one


Pause[]

Pause, Control(F2):Transfers(8):1, displays an argument, then pauses execution afterwards.

Syntax: Pause[]

:Pause [arg]
  • Where arg is either a literal or any variable type which Pause will display then pause execution of the rest of the program until the enter key is pressed
    • Pause will display arg on the next line, starting from where the the cursor initially was located. If the display reaches the seventh line, the display will 'scroll' the rest of the screen up so that the argument can be displayed
    • Pause will always display arg left-aligned
    • If an argument is too long to be displayed, the argument will be truncated and an arrow will be displayed indicating you may scroll left/right to read the entirety of the line.
  • If no argument is specified, the command merely pauses the execution until enter is pressed without displaying anything


Ex: Hello[]

:Pause "Hello World!"

*It should be noted that the program execution would pause until enter is pressed.

**You may get the ! symbol by pressing 2nd+Math(5):Probability(7):1, or Diamond+Divide(÷) on the TI-89 or 2nd+W on the TI-92 Plus and Voyage 200.


Ex: Pause[]

:Pause

*It should be noted that the program execution would pause until enter is pressed.


Output[]

Output, I/O(F3):6, allows the display of an argument in a location other than the next line. The item to be displayed is outputted to the specified coordinates supplied to the function. It is useful for formatted display.

Syntax: Output[]

:Output row,col,arg
  • Where row is a number (can be positive or negative) which determines the row location (vertically, in pixels) arg is to be displayed.
  • Where col is a number (can be positive or negative) which determines the column location (horizontally, in pixels) arg is to be displayed
  • Where arg is the argument to be displayed. This can be a number, string or list.
    • arg is displayed from left to right
    • if arg doesn't fit on one line, the parts that don't fit are cut out.
    • Each new Output command used overwrites the previous ones.


Ex: Basic[]

:Output 24,0,"HELLO WORLD"




HELLO WORLD

*HELLO WORLD is moved down two rows (24 pixels is the equivalent of two rows).


Ex: Too Long[]

:Output 0,100,"This is too long"


                This is to


Return[]

Return, Control(F2):Transfers(8):2, displays an argument on the home screen, or just returns to the home screen if no argument is supplied.

Syntax: Return[]

:Return [arg]
  • Where arg is any literal or variable.
  • This command will return the argument to the home screen only if used in a Function.
    • You can check to see whether you have a program or a function by the line under the title. If it says Prgm, then it is a program. If it says Func, then it is a function.
  • arg will always be right-aligned
  • When used without arg, whether in a Program or a Function, it will terminate the running of the code.


Ex: Return[]

Let's say you stored the value 5 in x (using 5→x) before executing the function. For the sake that this can only be used in a function, the appropriate tags and a name are supplied for this example.

temp()
:Func
:Return 2x+1
:EndFunc


▪temp()                 11


Input[]

How to receive words, numbers and more from the user

Input, I/O(F3):3, is a command which will display a string and wait for the user to input a value. The value will then be stored into the specified variable once ENTER is pressed. The behavior of this command changes depending on how many parameters are passed into it, explained below.

Syntax: Input[]

:Input [string],[var]
  • Where string is the optional string to display, and var is the optional variable to store the value to
  • If string is provided, the I/O screen will display that string on a new line, then wait for user input.
  • If string is not provided, the I/O screen will display a ? on a new line, then wait for user input.
  • If neither string nor var is provided, it will display the graph screen and wait for the user to select a coordinate (x value of coordinate is stored into xc, and the y value into yc)
  • Providing only string but not var results in an error ("Argument must be a variable name", errornum 140)


Ex: With String[]

:Input "X Value",x


X Value
5

*The value of 5 would be stored into x


Ex. Without String[]

:Input x


?
5

*The value of 5 would be stored into x


Ex: Without Arguments[]

:Input


InputStr[]

InputStr, I/O(F3):4, is much like input, but the values inputted into this command will always be a string (so no quotation marks are needed).

Syntax: InputStr[]

:InputStr [string,]var
  • Where string is an optional string to display instead of ?
  • Where var is the variable the string inputted will be stored into


Ex: InputStr[]

:InputStr "What is your name",name


What is your name
George

*Pressing ENTER would store "George" into the variable name.


Prompt[]

Prompt, I/O(F3):5, prompts the user to input a number of variables. While this can be used to input more than one variable with one command, it does not give you the flexibility to change what is displayed on screen.

Syntax: Prompt[]

:Prompt var[,var2][,var3][,…varN]
  • Where var2 through varN are all optional arguments. Arguments must be valid variable names.
    • Amount of arguments limited only by available memory
  • For each argument, Prompt will wait until a value is entered and ENTER pressed before asking for the next one.


Example: Prompt[]

:Prompt x,y


x?
5
y?
7

*This would store 5 into x and 7 into y


Request[]

Request, I/O(F3):1:2, puts a pop-up box on the current screen and allows the user to input a string into it, and then stores that string into a variable. Request can be used as a stand-alone command or as part of a Dialog block (more on those later).

Syntax: Request[]

:Request string,var
  • Where string is the string to be displayed before the input box
  • Where var is the variable the string gets stored into
  • Request automatically turns a-lock on, so the alpha button must be pressed once before numbers and other symbols may be entered


Ex: Request[]

:Request "name",x


PopUp[]

PopUp, I/O(F3):1:3, displays a pop up window with a number of choices for the user to choose between (passed in as a list). Then, the number of the choice the user selects will be stored into the variable given.

Syntax: PopUp[]

:PopUp itemlist,var
  • Where itemlist is a list of strings that will appear in the popup.
  • Where var is the variable that the number of the choice will be stored to.


Example: Correct Equation[]

:PopUp {"1+2=2","1/2=2","1-2=2","1*2=2"},x


DropDown[]

DropDownUnselected

A DropDown before being selected

A Dropdown after being selected

DropDown, I/O(F3):Dialog(1):4, displays a pop up window with (a) pull down menu(s) with a number of choices for the user to choose between (passed in as a list). Then, the number of the choice the user selects will be stored into the variable given. The DropDown command must be used in a Dialog...EndDlog, I/O(F3):Dialog(1):5, block. Placing multiple DropDowns will not return multiple pop up windows but will put all menus in the same window. DropDown can be paired with other dialog options such as Request or Title

Syntax: DropDown[]

:DropDown "Title",{"itemlist"},var
DropDownCode
  • Where Title is the title of the pull down menu
  • Where itemlist is a list of strings that will appear in the popup.
  • Where var is the variable that the number of the choice will be stored to.


Example: Correct Equation[]

:Dialog
:Title "Choose Correctly"
:DropDown "Choose the equation",{"1+2=2","1/2=2","1-2=2","1*2=2"},x
:EndDlog


DropDownMultiplechoice

What using the code results in

The Title will appear in the top of the pop up window

Passing in Arguments[]

Passing in arguments is vital to functions, and can be helpful in programs as well. In order to get an argument to be passed in, it must be declared in the opening parenthesis of the program editor. Then, when calling the program (by typing prgmname() in the home screen), you put the declared arguments into the parenthesis, like so: prgmname(arg). Note: for all of the following examples, the name of the function is "temp" (and it is a function).

Syntax[]

temp([var1][,var2][,var3][,…varN])
  • Where var1 through varN are all valid variable names
    • The amount of variables passed into the function is limited only by the amount of available memory
  • The variables passed in are local variables, as in they disappear the moment program execution stops (unlike from the previous ways of input, where the variables stick around until they are deleted).


Example: Temp[]

temp(x,y,z)
:Func
:Return x^2+(y*z)/100
:EndFunc


Let's say you call this program like so: temp(12,4,52). The following will appear on your home screen:

▪temp(12,4,52)      146.08


Custom Tool Bars[]

It is possible to create your own personal toolbar at the top of your TI-89 where you can place whatever programs and/or functions that you want for easy access. To create a tool bar, you must create a Custom...EndCustm, Control(F2):7, block. Each tab is a Title, I/O(F3):Dialog(1):7, and each item within the tab is an Item, I/O(F3):Dialog(1):8,.

Syntax[]

Custm()
:Custom
:Title "String"
:Item "var1"
:Item "varN"
:EndCustm
:CustmOn
  • Where Title is each tab
  • Where Item is each object in the tab
  • Where CustmOn changes from normal toolbar to the new one. CustmOn must be typed.

Example[]

EDITCUSTM

Editing the example custom program

Custm() :Prgm :Custom :Title "Solve(" :Title "Math" :Item "Factor(" :Item "Expand(" :EndCustm :CustmOn :EndPrgm
USECUSTM

Using custom program


Conditional Functions[]

Learn about controlling the flow of a program using conditionals such as If

If[]

If, Control(F2):1, is a command which will determine whether or not the next line of code is executed.

Syntax: If[]

:If condition
  • Where condition is an expression that resolves to be either true or false
    • If condition is true, then the code in the next line is executed. Otherwise that code is skipped.


Ex: If[]

:5→x
:If x=5
:Disp "True"


True




This page uses content from Wikibooks. The original book was at TI-Basic 89 Programming. The authors of this book were Skizzerz, Jimmyatic, T3thys::ben, and Dlrohrer2003. As with TI-BASIC Wiki, the text of Wikibooks is available under the Creative Commons Attribution-Share Alike License.
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