TI-84 Programming Tutorial

Master TI-BASIC programming on your TI-84 calculator. Learn to create programs, games, and custom functions with step-by-step tutorials, practical examples, and optimization techniques.

⏱️ 45 min read

💻 Programming Guide

🎮 Games & Apps

Game Development Tips

• Start with simple games and add features gradually
• Use getKey for real-time input in graphics games
• Keep game loops efficient to maintain smooth performance
• Test boundary conditions and edge cases thoroughly
• Add sound effects using the Tone command for better experience

🚀 Getting Started with TI-BASIC

TI-BASIC is the built-in programming language of the TI-84 calculator. It allows you to create custom programs to automate calculations, create games, and build useful tools for math and science.

Creating Your First Program

Let's start by creating a simple "Hello World" program to understand the basics.

Program Creation Steps:

Access Program Menu: Press PRGM to open the program menu

Create New Program: Arrow right to NEW, select 1:Create New, press ENTER

Name Your Program: Type HELLO (max 8 characters), press ENTER

Enter Code: You're now in the program editor, ready to write code

Program: HELLO
 PROGRAM:HELLO
 Disp "HELLO WORLD"
 Disp "Welcome to TI-BASIC!"
 Pause
 

Running Your Program

Once you've written your program, you need to know how to execute it.

Running Programs:

Exit Editor: Press 2ND + MODE (QUIT) to return to home screen

Access EXEC Menu: Press PRGM, then select EXEC tab

Select Program: Choose your program from the list (HELLO)

Execute: Press ENTER twice to run the program

HELLO WORLD
Welcome to TI-BASIC!

Press any key to continue...

Program Management

Learn essential program management tasks for efficient development.

Task	Menu Path	Steps	Notes
Edit Program	PRGM → EDIT	Select program, press ENTER	Makes changes to existing code
Delete Program	MEM → MGMT → 7:Prgm	Select program, press DEL	Permanently removes program
Rename Program	Edit → Change first line	Edit PROGRAM:NAME line	Must follow naming rules
Copy Program	Edit → Copy code	Create new, paste code	Useful for variations
Archive Program	MEM → MGMT → 5:Archive	Select program type	Protects from RAM resets

Program Naming Rules

• Program names can be 1-8 characters long
• Use only letters and numbers (A-Z, 0-9)
• Names are case-insensitive (HELLO = hello)
• Avoid names that conflict with built-in functions
• Choose descriptive names for easy identification

📝 Basic Programming Concepts

Understanding fundamental programming concepts is essential for creating effective TI-BASIC programs. Let's explore variables, input/output, and basic program structure.

Variables and Data Types

TI-BASIC supports several types of variables for storing different kinds of data.

Variable Type	Examples	Range/Limits	Usage
Real Numbers	A, B, X, Y	±1×10⁻⁹⁹ to ±9.9999...×10⁹⁹	General calculations
Lists	L1, L2, L₃	Up to 999 elements	Arrays of numbers
Matrices	[A], [B], [C]	Up to 99×99 elements	2D data arrays
Strings	Str1, Str2, Str0	Up to 255 characters	Text and messages
Graphics	Pic1, Pic2, Pic0	95×63 pixels	Images and graphics

Input and Output Commands

Interacting with users is fundamental to useful programs.

Input/Output Examples
 ; Display text
 Disp "Enter a number:"
 
 ; Get user input
 Input "Number: ",A
 
 ; Display variable
 Disp "You entered:",A
 
 ; Prompt for multiple inputs
 Prompt B,C
 

Mathematical Operations

TI-BASIC supports all standard mathematical operations and functions.

Operation	Symbol	Example	Result
Addition	+	5 + 3	8
Subtraction	-	10 - 4	6
Multiplication	*	6 * 7	42
Division	/	15 / 3	5
Exponentiation	^	2^3	8
Square Root	√(	√(16)	4
Absolute Value	abs(	abs(-5)	5

Your First Useful Program

Let's create a program that calculates the area of a circle.

Program: CIRCLE
 PROGRAM:CIRCLE
 ClrHome
 Disp "CIRCLE AREA CALCULATOR"
 Disp ""
 Input "Radius: ",R
 π*R^2→A
 Disp "Area =",A
 Pause
 

Memory Considerations

TI-BASIC programs run in RAM, which is limited. Large programs or those using many variables may cause "ERR:MEMORY" errors. Archive important programs to protect them from RAM clearing.

🔄 Control Structures

Control structures allow your programs to make decisions and repeat actions. These are essential for creating intelligent, interactive programs.

Conditional Statements (If-Then-Else)

Use conditional statements to make your programs respond differently based on user input or calculations.

If-Then-Else Structure
 ; Basic If-Then
 If A>0
 Then
 Disp "Positive number"
 End
 
 ; If-Then-Else
 If A>0
 Then
 Disp "Positive"
 Else
 Disp "Zero or Negative"
 End
 

Comparison Operators

These operators are essential for creating conditions in your programs.

Operator	Meaning	Example	True When
=	Equal to	A = 5	A equals 5
≠	Not equal to	A ≠ 0	A is not zero
>	Greater than	A > 10	A is greater than 10
≥	Greater than or equal	A ≥ 0	A is zero or positive
<	Less than	A < 100	A is less than 100
≤	Less than or equal	A ≤ 50	A is 50 or less

Loops

Loops allow your programs to repeat actions, making them more powerful and efficient.

For Loops

Use For loops when you know how many times to repeat something.

For Loop Examples
 ; Count from 1 to 10
 For(I,1,10)
 Disp I
 End
 
 ; Count by 2s from 0 to 20
 For(I,0,20,2)
 Disp I
 End
 
 ; Calculate factorial
 1→F
 For(I,1,N)
 F*I→F
 End
 

While Loops

Use While loops when you need to repeat based on a condition.

While Loop Examples
 ; Number guessing game
 randInt(1,100)→N
 0→G
 While G≠N
 Input "Guess: ",G
 If G>N
 Disp "Too high"
 If G<N
 Disp "Too low"
 End
 Disp "Correct!"
 End
 

Practice Program: Grade Calculator

Let's combine what we've learned to create a useful grade calculator.

Program: GRADES
 PROGRAM:GRADES
 ClrHome
 Disp "GRADE CALCULATOR"
 Input "Number of grades: ",N
 0→S
 For(I,1,N)
 Input "Grade "+toString(I)+": ",G
 S+G→S
 End
 S/N→A
 Disp "Average: ",A
 If A≥90
 Disp "Grade: A"
 If A≥80 and A<90
 Disp "Grade: B"
 If A≥70 and A<80
 Disp "Grade: C"
 If A≥60 and A<70
 Disp "Grade: D"
 If A<60
 Disp "Grade: F"
 Pause
 

Control Structure Best Practices

• Use proper indentation to make code readable
• Always match If with End statements
• Prefer loops over repetitive code
• Use meaningful variable names (I for index, N for count)
• Test edge cases (what if user enters 0 grades?)

🚀 Advanced Features

Advanced TI-BASIC features allow you to create sophisticated programs with graphics, file operations, and complex data handling.

Working with Lists

Lists are powerful for handling multiple data values efficiently.

List Operations
 ; Create and fill a list
 1,2,3,4,5→L₁
 
 ; Access list elements
 L₁(3)→A ; A = 3
 10→L₁(2) ; Change 2nd element to 10
 
 ; List operations
 dim(L₁)→S ; Get list size
 sum(L₁)→T ; Sum all elements
 max(L₁)→M ; Find maximum
 min(L₁)→N ; Find minimum
 
 ; Sort list
 SortA(L₁) ; Sort ascending
 SortD(L₁) ; Sort descending
 

Graphics and Animation

Create visual programs using the calculator's graphics capabilities.

Basic Graphics
 ; Clear and setup graphics
 ClrDraw
 AxesOff
 GridOff
 
 ; Draw points and lines
 Pt-On(50,30) ; Draw point at (50,30)
 Line(0,0,95,63) ; Draw diagonal line
 Circle(47,31,20) ; Circle at center with radius 20
 
 ; Text on graphics screen
 Text(10,10,"Hello Graphics!")
 
 ; Simple animation
 For(X,0,90,5)
 ClrDraw
 Pt-On(X,30)
 DispGraph
 End
 

Subroutines and Modularity

Break complex programs into smaller, manageable pieces.

Main Program with Subroutines
 ; Main program
 PROGRAM:MAIN
 Menu("CALCULATOR","Add",A,"Subtract",S,"Quit",Q)
 
 Lbl A
 prgmADD ; Call ADD program
 Stop
 
 Lbl S
 prgmSUB ; Call SUB program
 Stop
 
 Lbl Q
 Stop
 

Memory Management

The TI-84 has limited RAM (~24KB). Large programs or extensive use of lists/matrices can quickly fill memory. Always test programs on a calculator with typical memory usage.

🎮 Game Development

Creating games is one of the most exciting aspects of TI-BASIC programming. Games help you learn advanced programming concepts while creating something fun.

Game Design Principles

Before coding, consider these fundamental game design elements.

Element	Description	Implementation	Example
Player Input	How players control the game	getKey, Input, Menu	Arrow keys for movement
Game State	Current condition of game	Variables, lists	Player position, score, lives
Graphics	Visual representation	Pt-On, Text, Pixel test	Player sprite, obstacles
Game Loop	Main program cycle	While loop	Update, draw, check conditions
Win/Lose Conditions	How game ends	If statements	Reach goal, lose all lives

Simple Game: Number Guessing

Let's start with a text-based guessing game to learn game programming basics.

Program: GUESS
 PROGRAM:GUESS
 ClrHome
 Disp "NUMBER GUESSING GAME"
 Disp "I'm thinking of a number"
 Disp "between 1 and 100"
 randInt(1,100)→N
 0→T ; Tries counter
 0→G ; User's guess
 
 While 1 ; Game loop
 ; Increment tries
 T+1→T
 Input "Guess #"+toString(T)+": ",G
 If G>N
 Disp "Too high!"
 If G<N
 Disp "Too low!"
 End
 If G=N
 Disp "Correct! You got it in"
 Disp T," tries"
 Pause
 Stop
 End
 

Graphics-Based Game: Snake

Now let's create a simple Snake game using graphics.

Program: SNAKE (Simplified Version)
 PROGRAM:SNAKE
 ClrDraw
 47→X ; Snake X position
 31→Y ; Snake Y position
 1→D ; Direction (1=right, 2=down, 3=left, 4=up)
 0→S ; Score
 
 ; Place food randomly
 randInt(5,90)→FX
 randInt(5,58)→FY
 Pt-On(FX,FY)
 
 While 1 ; Game loop
 ; Check for key press
 getKey→K
 If K=26 ; Up arrow
 4→D
 If K=25 ; Down arrow
 2→D
 If K=24 ; Left arrow
 3→D
 If K=27 ; Right arrow
 1→D
 
 ; Move snake
 If D=1
 X+2→X
 If D=2
 Y+2→Y
 If D=3
 X-2→X
 If D=4
 Y-2→Y
 
 ; Check boundaries
 If X<0 or X>94 or Y<0 or Y>62
 Then
 Disp "GAME OVER!"
 Disp "Score: ",S
 Stop
 End
 
 ; Check if food eaten
 If abs(X-FX)≤2 and abs(Y-FY)≤2
 Then
 S+10→S
 randInt(5,90)→FX
 randInt(5,58)→FY
 End
 
 ; Draw everything
 ClrDraw
 Pt-On(X,Y) ; Snake head
 Pt-On(FX,FY) ; Food
 Text(1,1,"Score:"+toString(S))
 DispGraph
 End
 

⚡ Optimization Techniques

Writing efficient TI-BASIC code is crucial for creating responsive programs. Learn techniques to make your programs run faster and use memory more effectively.

Speed Optimization

Several techniques can significantly improve your program's execution speed.

Technique	Slow Method	Fast Method	Speed Gain
Variable Storage	A+1→A	IS>(A,MAX)	~2x faster
List Operations	For loop with L₁(I)	Built-in list functions	~5x faster
String Building	Str1+Str2→Str1	Pre-allocate string size	~3x faster
Graphics	Multiple Pt-On calls	StorePic/RecallPic	~4x faster
Calculations	Repeated complex math	Store intermediate results	Variable

Memory Optimization

Efficient memory usage prevents crashes and allows for larger programs.

Memory-Efficient Programming
 ; Clear unused variables
 DelVar A
 DelVar B
 
 ; Use lists efficiently
 →L₁ ; Clear list
 ClrList L₂,L₃ ; Clear multiple lists
 
 ; Reuse variables
 Input "Value: ",A
 A*2→A ; Reuse A instead of new variable
 
 ; Archive large programs
 ; Use 2ND+MEM→5:Archive→7:Prgm
 

Code Size Optimization

Smaller code means faster loading and more available memory.

Code Size Reduction Techniques
 ; Use shorter variable names
 A ; Instead of COUNTER
 
 ; Combine operations
 A+1→A:B-1→B ; Two operations on one line
 
 ; Use implied multiplication
 2A ; Instead of 2*A
 πR² ; Instead of π*R^2
 
 ; Eliminate unnecessary commands
 A ; Displays A (instead of Disp A)
 
 ; Use built-in functions
 rand ; Random number 0-1
 int(rand*6)+1 ; Dice roll 1-6
 

Algorithm Optimization

Choose efficient algorithms for better performance.

Efficient Algorithm Examples
 ; Efficient factorial calculation
 PROGRAM:FACTFAST
 Input "N: ",N
 seq(X,X,1,N)→L₁
 prod(L₁)→F
 Disp F
 
 ; Fast prime checking
 PROGRAM:ISPRIME
 Input "Number: ",N
 If N≤1 or (N>2 and fPart(N/2)=0)
 Then
 Disp "Not prime"
 Stop
 End
 For(I,3,√(N),2)
 If fPart(N/I)=0
 Then
 Disp "Not prime"
 Stop
 End
 End
 Disp "Prime"
 

Optimization Trade-offs

Remember that optimization often involves trade-offs between speed, memory usage, and code readability. Optimize only when necessary, and always test thoroughly after making changes.

🔧 Practical Applications

TI-BASIC programming shines when solving real-world problems. Here are practical programs that demonstrate useful applications for academics and daily life.

Scientific Calculator Programs

Extend your calculator's capabilities with custom scientific functions.

Program: QUADFORM (Quadratic Formula Solver)
 PROGRAM:QUADFORM
 ClrHome
 Disp "QUADRATIC FORMULA"
 Disp "ax² + bx + c = 0"
 Input "a: ",A
 Input "b: ",B
 Input "c: ",C
 
 B²-4AC→D ; Discriminant
 
 If D<0
 Then
 Disp "No real solutions"
 Disp "Complex solutions:"

(-B)/(2A)→R
 √(-D)/(2A)→I
 Disp R," + ",I,"i"
 Disp R," - ",I,"i"
 Else

(-B+√(D))/(2A)→X

(-B-√(D))/(2A)→Y
 Disp "x₁ = ",X
 Disp "x₂ = ",Y
 End
 Pause
 

Physics and Engineering Programs

Solve common physics problems with automated calculations.

Program: MOTION (Kinematic Equations)
 PROGRAM:MOTION
 Menu("KINEMATICS","Find Velocity",V,"Find Distance",D,"Find Time",T,"Quit",Q)
 
 Lbl V
 Disp "v = v₀ + at"
 Input "Initial velocity: ",V0
 Input "Acceleration: ",A
 Input "Time: ",T
 V0+AT→V
 Disp "Final velocity: ",V
 Pause
 Stop
 
 Lbl D
 Disp "d = v₀t + ½at²"
 Input "Initial velocity: ",V0
 Input "Acceleration: ",A
 Input "Time: ",T
 V0T+0.5AT²→D
 Disp "Distance: ",D
 Pause
 Stop
 
 Lbl Q
 Stop
 

Financial Calculator Programs

Create programs for financial calculations and planning.

Program: COMPOUND (Compound Interest Calculator)
 PROGRAM:COMPOUND
 ClrHome
 Disp "COMPOUND INTEREST"
 Disp "A = P(1 + r/n)^(nt)"
 Input "Principal ($): ",P
 Input "Annual rate (%): ",R
 R/100→R ; Convert to decimal
 Input "Times compounded/year: ",N
 Input "Years: ",T
 
 P(1+R/N)^(NT)→A
 A-P→I ; Interest earned
 
 Disp "Final Amount: $",round(A,2)
 Disp "Interest Earned: $",round(I,2)
 Pause
 

Statistics and Data Analysis

Process and analyze data sets with custom statistical programs.

Program: STATS (Descriptive Statistics)
 PROGRAM:STATS
 ClrHome
 Disp "DESCRIPTIVE STATISTICS"
 Input "How many values? ",N
 
 ; Input data
 For(I,1,N)
 Input "Value "+toString(I)+": ",X
 X→L₁(I)
 End
 
 ; Calculate statistics
 mean(L₁)→M
 median(L₁)→MED
 stdDev(L₁)→SD
 min(L₁)→MIN
 max(L₁)→MAX
 sum(L₁)→SUM
 
 ; Display results
 ClrHome
 Disp "RESULTS:"
 Disp "Mean: ",round(M,3)
 Disp "Median: ",MED
 Disp "Std Dev: ",round(SD,3)
 Disp "Min: ",MIN
 Disp "Max: ",MAX
 Disp "Sum: ",SUM
 Pause
 

Utility Programs

Create helpful utility programs for everyday calculator use.

Program: CONVERT (Unit Converter)
 PROGRAM:CONVERT
 Menu("UNIT CONVERTER","Temperature",T,"Length",L,"Weight",W,"Quit",Q)
 
 Lbl T
 Menu("TEMPERATURE","F to C",FC,"C to F",CF,"Back",B)
 
 Lbl FC
 Input "Fahrenheit: ",F

(F-32)*5/9→C
 Disp "Celsius: ",round(C,2)
 Pause
 Goto T
 
 Lbl CF
 Input "Celsius: ",C
 C*9/5+32→F
 Disp "Fahrenheit: ",round(F,2)
 Pause
 Goto T
 
 Lbl Q
 Stop
 

💻 Try These Programs

🐛 Debugging & Testing

Every programmer encounters bugs. Learning to effectively debug and test your TI-BASIC programs is essential for creating reliable, professional-quality code.

Common Error Types

Understanding common TI-BASIC errors helps you identify and fix problems quickly.

Error Message	Cause	Solution	Prevention
ERR:SYNTAX	Invalid command syntax	Check command spelling and syntax	Use program editor carefully
ERR:MEMORY	Insufficient RAM	Archive programs, clear variables	Optimize memory usage
ERR:DIVIDE BY 0	Division by zero	Add input validation	Check denominators before division
ERR:INVALID DIM	List/matrix size error	Check list dimensions	Validate list operations
ERR:ARGUMENT	Invalid function argument	Check function parameter ranges	Validate inputs before calculations

Debugging Techniques

Use these systematic approaches to find and fix bugs in your programs.

Debug Output Example
 ; Add debug output to track program flow
 PROGRAM:DEBUG
 Input "Enter N: ",N
 Disp "DEBUG: N = ",N ; Debug output
 
 If N≤0
 Then
 Disp "DEBUG: Invalid input"
 Stop
 End
 
 1→F
 For(I,1,N)
 Disp "DEBUG: I=",I," F=",F
 F*I→F
 End
 
 Disp "Result: ",F
 

Input Validation

Proper input validation prevents many runtime errors.

Robust Input Validation
 PROGRAM:VALIDATE
 ClrHome
 Disp "SAFE DIVISION"
 
 ; Get and validate first number
 Lbl A
 Input "Numerator: ",A
 If A≠int(A) and abs(A)>1E10
 Then
 Disp "Number too large!"
 Pause
 Goto A
 End
 
 ; Get and validate denominator
 Lbl B
 Input "Denominator: ",B
 If B=0
 Then
 Disp "Cannot divide by zero!"
 Pause
 Goto B
 End
 
 ; Perform calculation
 A/B→R
 Disp "Result: ",R
 Pause
 

Testing Strategies

Systematic testing ensures your programs work correctly in all situations.

Program Testing Checklist:

Normal Cases: Test with typical, expected input values

Edge Cases: Test with boundary values (0, 1, maximum values)

Invalid Input: Test with negative numbers, decimals where integers expected

Extreme Values: Test with very large or very small numbers

Memory Stress: Test with low available memory conditions

Error Handling Patterns

Implement robust error handling to create professional programs.

Error Handling Template
 PROGRAM:ROBUST
 ClrHome
 
 ; Main program loop with error handling
 Lbl MAIN
 Menu("PROGRAM","Calculate",C,"Help",H,"Quit",Q)
 
 Lbl C
 ; Try calculation
 Input "Value: ",X
 
 ; Validate input
 If X<0
 Then
 Disp "Error: Negative input"
 Disp "Please use positive numbers"
 Pause
 Goto MAIN
 End
 
 ; Perform calculation
 √(X)→R
 Disp "Square root: ",R
 Pause
 Goto MAIN
 
 Lbl H
 ClrHome
 Disp "HELP:"
 Disp "This program calculates"
 Disp "square roots of positive"
 Disp "numbers only."
 Pause
 Goto MAIN
 
 Lbl Q
 ClrHome
 Disp "Thanks for using this program!"
 Stop
 

Professional Programming Habits

• Always validate user input before processing
• Provide clear, helpful error messages
• Include help or instruction screens
• Test with a variety of input scenarios
• Comment your code for future maintenance
• Use consistent naming conventions

← Graphing Tutorial 📚 All Tutorials Scientific Tutorial →

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