METADATA:
Name: BazzBasic
Description: BazzBasic BASIC interpreter language reference. Use when writing, debugging, or explaining BazzBasic code (.bas files). Triggers on BazzBasic syntax, BASIC programming with $ and # suffixes, SDL2 graphics in BASIC, or references to BazzBasic interpreter features
About: BazzBasic is built around one simple idea: starting programming should feel nice and even fun. Ease of learning, comfort of exploration and small but important moments of success. Just like the classic BASICs of decades past, but with a fresh and modern feel.
Purpose: This guide has been provided with the idea that it would be easy and efficient for a modern AI to use this guide and through this either guide a new programmer to the secrets of BazzBasic or, if necessary, generate code himself.
Version: This guide is written for BazzBasic version 1.0 and is updated 19.03.2026 09:51 Finnish time.
BazzBasic Language Reference
BazzBasic is a BASIC interpreter for .NET 10 with SDL2 graphics and SDL2_mixer sound support. It is not a clone of any previous BASIC — it aims to be easy, fun, and modern. Released under MIT license.
Version: 1.0 (Released February 22, 2026)
Author: Kristian Virtanen (krisu.virtanen@gmail.com)
Platform: Windows (x64 primary); Linux/macOS possible with effort
Dependencies: SDL2.dll, SDL2_mixer (bundled).
Github: https://github.com/EkBass/BazzBasic
Homepage: https://ekbass.github.io/BazzBasic/
Manual: "https://ekbass.github.io/BazzBasic/manual/#/"
Hugginface AI manual: https://huggingface.co/datasets/EkBass/BazzBasic_AI_Guide
Examples: "https://github.com/EkBass/BazzBasic/tree/main/Examples"
Github_repo: "https://github.com/EkBass/BazzBasic"
Github_discussions: "https://github.com/EkBass/BazzBasic/discussions"
Discord_channel: "https://discord.com/channels/682603735515529216/1464283741919907932"
Thinbasic subforum: "https://www.thinbasic.com/community/forumdisplay.php?401-BazzBasic"
Usage:
This file is created as a guide specifically for the AI. With this, the AI can not only code itself with BazzBasic, but also guide the user with it.
Feed the file as it is to the AI, as an attachment, as a project file, etc.
Few examples:
raycaster_3d: https://raw.githubusercontent.com/EkBass/BazzBasic/refs/heads/main/Examples/raycaster_3d_optimized.bas
voxel_terrain: https://raw.githubusercontent.com/EkBass/BazzBasic/refs/heads/main/Examples/voxel_terrain.bas
sprite load: https://github.com/EkBass/BazzBasic/blob/main/Examples/countdown_demo.bas
Eliza: https://github.com/EkBass/BazzBasic/blob/main/Examples/Eliza.bas
CLI Usage
| Command | Action |
|---|---|
bazzbasic.exe |
Launch IDE |
bazzbasic.exe file.bas |
Run program |
bazzbasic.exe -exe file.bas |
Create standalone .exe |
bazzbasic.exe -lib file.bas |
Create tokenized library (.bb) |
IDE shortcuts: F5 run, Ctrl+N/O/S new/open/save, Ctrl+Shift+S save as, Ctrl+W close tab, Ctrl+F find, Ctrl+H replace.
External syntax colors.
BazzBasic IDE is developed just so double-clicking bazzbasic.exe would bring something in the screen of a newbie. A person can use it, but it stands no chance for more advanced editors.
There are syntax color files for Notepad++, Geany and Visual Studio Code available at https://github.com/EkBass/BazzBasic/tree/main/extras
Syntax Fundamentals
Variables and Constants
Forget traditional BASIC types. Suffixes in BazzBasic define mutability, not data type.
Variables and arrays in BazzBasic are typeless: hold numbers or strings interchangeably
LET a$ ' Declare without value
LET name$ = "Alice" ' Variable, string (mutable, $ suffix)
LET age$ = 19 ' Variable, integer (mutable, $ suffix)
LET price$ = 1.99 ' Variable, decimal (mutable, $ suffix)
LET PI# = 3.14159 ' Constant (immutable, # suffix)
LET x$, y$, z$ = 10 ' Multiple declaration
- All variables require
$suffix, constants require# - Typeless: hold numbers or strings interchangeably
- Must declare with
LETbefore use (except FOR/INPUT which auto-declare) - Assignment after declaration:
x$ = x$ + 1(no LET needed) - Case-insensitive:
PRINT,print,Printall work - Naming: letters, numbers, underscores; cannot start with number
Comparison Behavior
"123" = 123 is TRUE (cross-type comparison), but slower — keep types consistent.
Scope
- Main code shares one scope (even inside IF blocks)
DEF FNfunctions have completely isolated scope- Only global constants (
#) are accessible inside functions
Multiple Statements Per Line
COLOR 14, 0 : CLS : PRINT "Hello"
Comments
REM This is a comment
' This is also a comment
PRINT "Hello" ' Inline comment
Escape Sequences in Strings
| Sequence | Result |
|---|---|
\" |
Quote |
\n |
Newline |
\t |
Tab |
\\ |
Backslash |
Arrays
DIM scores$ ' Declare (must use DIM)
DIM a$, b$, c$ ' Multiple declaration
scores$(0) = 95 ' Numeric index (0-based)
scores$("name") = "Alice" ' String key (associative)
matrix$(0, 1) = "A2" ' Multi-dimensional
data$(1, "header") = "Name" ' Mixed indexing
- Array names must end with
$ - Fully dynamic: numeric, string, multi-dimensional, mixed indexing
- Arrays cannot be passed directly to functions — pass values of individual elements
- Accessing uninitialized elements is an error — check with
HASKEYfirst
Array Functions
| Function | Description |
|---|---|
LEN(arr$()) |
Element count (note: empty parens) |
HASKEY(arr$(key)) |
1 if exists, 0 if not |
DELKEY arr$(key) |
Remove element |
DELARRAY arr$ |
Remove entire array (can re-DIM after) |
Operators
Arithmetic
+ (add/concatenate), -, *, / (returns float)
Comparison
= or ==, <> or !=, <, >, <=, >=
Logical
AND, OR, NOT
Precedence (high to low)
() → NOT → *, / → +, - → comparisons → AND → OR
User-Defined Functions
DEF FN add$(a$, b$)
RETURN a$ + b$
END DEF
PRINT FN add$(3, 4) ' Call with FN prefix
- Function name must end with
$, called withFNprefix - Must be defined before called (top of file or via INCLUDE)
- Parameters passed by value
- Completely isolated scope: no access to global variables, only global constants (
#) - Labels inside functions are local — GOTO/GOSUB cannot jump outside (error)
- Supports recursion
- Tip: put functions in separate files,
INCLUDEat program start
Control Flow
IF Statements
' Block IF (END IF and ENDIF both work)
IF x$ > 10 THEN
PRINT "big"
ELSEIF x$ > 5 THEN
PRINT "medium"
ELSE
PRINT "small"
ENDIF
' One-line IF (GOTO/GOSUB only)
IF lives$ = 0 THEN GOTO [game_over]
IF key$ = KEY_ESC# THEN GOTO [menu] ELSE GOTO [continue]
IF ready$ = 1 THEN GOSUB [start_game]
FOR Loops
FOR i$ = 1 TO 10 STEP 2 ' Auto-declares variable, STEP optional
PRINT i$
NEXT
FOR i$ = 10 TO 1 STEP -1 ' Count down
PRINT i$
NEXT
WHILE Loops
WHILE x$ < 100
x$ = x$ * 2
WEND
Labels, GOTO, GOSUB
[start]
GOSUB [subroutine]
GOTO [start]
END
[subroutine]
PRINT "Hello"
RETURN
Dynamic Jumps (Labels as Variables)
LET target$ = "[menu]"
GOTO target$ ' Variable holds label string
LET dest# = "[jump]"
GOSUB dest# ' Constants work too
If you want to make a dynamic jump, use the "[" and "]" characters to indicate to BazzBasic that it is specifically a label.
LET target$ = "[menu]" ' Correct way
LET target$ = "menu" ' Incorrect way
Other
| Command | Description |
|---|---|
SLEEP ms |
Pause execution |
END |
Terminate program |
I/O Commands
| Command | Description |
|---|---|
PRINT expr; expr |
Output (; = no space, , = tab) |
PRINT "text"; |
Trailing ; suppresses newline |
INPUT "prompt", var$ |
Read input (splits on whitespace/comma) |
INPUT "prompt", a$, b$ |
Read multiple values |
INPUT var$ |
Default prompt "? " |
LINE INPUT "prompt", var$ |
Read entire line including spaces |
CLS |
Clear screen |
LOCATE row, col |
Move cursor (1-based) |
COLOR fg, bg |
Set colors (0-15 palette) |
GETCONSOLE(row, col, type) |
Console read: 0=char(ASCII), 1=fg, 2=bg |
INKEY |
Non-blocking key check (0 if none, >256 for special keys) |
KEYDOWN(key#) |
Returns TRUE if specified key is currently held down |
INPUT vs LINE INPUT
| Feature | INPUT | LINE INPUT |
|---|---|---|
| Reads spaces | No (splits) | Yes |
| Multiple variables | Yes | No |
| Default prompt | "? " |
None |
INKEY vs KEYDOWN
| Feature | INKEY | KEYDOWN |
|---|---|---|
| Returns | Key value or 0 | TRUE/FALSE |
| Key held | Reports once | Reports while held |
| Use case | Menu navigation | Game movement, held keys |
' KEYDOWN example — smooth movement
IF KEYDOWN(KEY_LEFT#) THEN x$ = x$ - 5
IF KEYDOWN(KEY_RIGHT#) THEN x$ = x$ + 5
Math Functions
| Function | Description |
|---|---|
ABS(n) |
Absolute value |
ATAN(n) |
Returns the arc tangent of n |
BETWEEN(n, min, max) |
TRUE if n is in range |
CEIL(n) |
Rounds up |
CINT(n) |
Convert to integer (rounds) |
COS(n) |
Returns the cosine of an angle |
CLAMP(n, min, max) |
Constrain value to range |
DEG(radians) |
Radians to degrees |
DISTANCE(x1,y1,x2,y2) |
2D Euclidean distance |
DISTANCE(x1,y1,z1,x2,y2,z2) |
3D Euclidean distance |
EXP(n) |
Exponential (e^n) |
FLOOR(n) |
Rounds down |
INT(n) |
Truncate toward zero |
LERP(start, end, t) |
Linear interpolation (t = 0.0-1.0) |
LOG(n) |
Natural log |
MAX(a, b) |
Returns higher from a & b |
MIN(a, b) |
Returns smaller from a & b |
MOD(a, b) |
Remainder |
POW(base, exp) |
Power |
RAD(degrees) |
Degrees to radians |
RND(n) |
Random 0 to n-1 |
ROUND(n) |
Standard rounding |
SGN(n) |
Sign (-1, 0, 1) |
SIN(n) |
Returns the sine of n |
SQR(n) |
Square root |
TAN(n) |
Returns the tangent of n |
Math Constants
| Constant | Value | Notes |
|---|---|---|
PI |
3.14159265358979 | 180° |
HPI |
1.5707963267929895 | 90° (PI/2) |
QPI |
0.7853981633974483 | 45° (PI/4) |
TAU |
6.283185307179586 | 360° (PI*2) |
EULER |
2.718281828459045 | e |
All are raw-coded values — no math at runtime, maximum performance.
Fast Trigonometry (Lookup Tables)
For graphics-intensive applications — ~20x faster than SIN/COS, 1-degree precision.
FastTrig(TRUE) ' Enable lookup tables (~5.6 KB)
LET x$ = FastCos(45) ' Degrees, auto-normalized to 0-359
LET y$ = FastSin(90)
LET r$ = FastRad(180) ' Degrees to radians (doesn't need FastTrig)
FastTrig(FALSE) ' Free memory when done
Use FastTrig when: raycasting, rotating sprites, particle systems, any loop calling trig hundreds of times per frame. Use regular SIN/COS when: high precision needed, one-time calculations.
String Functions
| Function | Description |
|---|---|
ASC(s$) |
Character to ASCII code |
CHR(n) |
ASCII code to character |
INSTR(s$, search$) |
Find substring position (0 = not found) |
INSTR(start$, s$, search$) |
Find substring starting from position start$ (0 = not found) |
INVERT(s$) |
Inverts a string |
LCASE(s$) |
Converts to lowercase |
LEFT(s$, n) |
First n characters |
LEN(s$) |
String length |
LTRIM(s$) |
Left trim |
MID(s$, start, len) |
Substring (1-based) len optional |
REPEAT(s$, n) |
Repeat s$ for n times |
REPLACE(s$, old$, new$) |
Replace all occurrences |
RIGHT(s$, n) |
Last n characters |
RTRIM(s$) |
Right trim |
SPLIT(s$, delim$, arr$) |
Split into array |
SRAND(n) |
Returns random string length of n from allowed chars (letters, numbers and "_") |
STR(n) |
Number to string |
TRIM(s$) |
Remove leading/trailing spaces |
UCASE(s$) |
Converts to uppercase |
VAL(s$) |
String to number |
File I/O
' Simple text file
FileWrite "save.txt", data$
LET data$ = FileRead("save.txt")
' Array read/write (key=value format)
DIM a$
a$("name") = "player1"
a$("score") = 9999
FileWrite "scores.txt", a$
DIM b$
LET b$ = FileRead("scores.txt")
PRINT b$("name") ' Output: player1
Array file format:
name=player1
score=9999
multi,dim,key=value
| Function/Command | Description |
|---|---|
FileRead(path) |
Read file; returns string or populates array |
FileWrite path, data |
Write string or array to file |
FileExists(path) |
Returns 1 if file exists, 0 if not |
FileDelete path |
Delete a file |
FileList(path$, arr$) |
List files in directory into array |
Network (HTTP)
DIM response$
LET response$ = HTTPGET("https://api.example.com/data")
PRINT response$
DIM result$
LET result$ = HTTPPOST("https://api.example.com/post", "{""key"":""value""}")
PRINT result$
- Returns response body as string
- Supports HTTPS
- Use
""inside strings to escape quotes in JSON bodies - Timeout handled gracefully — returns error message string on failure
Sound (SDL2_mixer)
DIM bgm$
LET bgm$ = LOADSOUND("music.wav")
LET sfx$ = LOADSOUND("jump.wav")
SOUNDREPEAT(bgm$) ' Loop continuously
SOUNDONCE(sfx$) ' Play once
SOUNDSTOP(bgm$) ' Stop specific sound
SOUNDSTOPALL ' Stop all sounds
| Command | Description |
|---|---|
LOADSOUND(path) |
Load sound file, returns ID |
SOUNDONCE(id$) |
Play once |
SOUNDREPEAT(id$) |
Loop continuously |
SOUNDSTOP(id$) |
Stop specific sound |
SOUNDSTOPALL |
Stop all sounds |
- Formats: WAV (recommended), MP3, others via SDL2_mixer
- Thread-safe, multiple simultaneous sounds supported
- Load sounds once at startup for performance
Graphics (SDL2)
Screen Setup
SCREEN 12 ' 640x480 VGA mode
SCREEN 0, 800, 600, "Title" ' Custom size with title
Modes: 0=640x400, 1=320x200, 2=640x350, 7=320x200, 9=640x350, 12=640x480, 13=320x200
Fullscreen
FULLSCREEN TRUE ' Borderless fullscreen
FULLSCREEN FALSE ' Windowed mode
Call after SCREEN.
VSync
VSYNC(TRUE) ' Enable (default) — caps to monitor refresh
VSYNC(FALSE) ' Disable — unlimited FPS, may tear
Double Buffering (Required for Animation)
SCREENLOCK ON ' Start buffering
' ... draw commands ...
SCREENLOCK OFF ' Display frame
SLEEP 16 ' ~60 FPS
SCREENLOCK without argument = SCREENLOCK ON. Do math/logic outside SCREENLOCK block.
Drawing Primitives
| Command | Description |
|---|---|
PSET (x, y), color |
Draw pixel |
POINT(x, y) |
Read pixel color (returns RGB integer) |
LINE (x1,y1)-(x2,y2), color |
Draw line |
LINE (x1,y1)-(x2,y2), color, B |
Box outline |
LINE (x1,y1)-(x2,y2), color, BF |
Filled box (faster than CLS) |
CIRCLE (cx, cy), r, color |
Circle outline |
CIRCLE (cx, cy), r, color, 1 |
Filled circle |
PAINT (x, y), fill, border |
Flood fill |
RGB(r, g, b) |
Create color (0-255 each) |
Shape/Sprite System
DIM sprite$
sprite$ = LOADSHAPE("RECTANGLE", 50, 50, RGB(255,0,0)) ' Types: RECTANGLE, CIRCLE, TRIANGLE
sprite$ = LOADIMAGE("player.png") ' PNG (with alpha) or BMP
MOVESHAPE sprite$, x, y ' Position (top-left point)
ROTATESHAPE sprite$, angle ' Absolute degrees
SCALESHAPE sprite$, 1.5 ' 1.0 = original
SHOWSHAPE sprite$
HIDESHAPE sprite$
DRAWSHAPE sprite$ ' Render
REMOVESHAPE sprite$ ' Free memory
- PNG recommended (full alpha transparency 0-255), BMP for legacy
- Images positioned by their top-left point
- Rotation is absolute, not cumulative
- Always REMOVESHAPE when done to free memory
Sprite Sheets (LOADSHEET)
DIM sprites$
LOADSHEET sprites$, spriteW, spriteH, "sheet.png"
' Access sprites by 1-based index
MOVESHAPE sprites$(index$), x#, y#
DRAWSHAPE sprites$(index$)
- Sprites indexed left-to-right, top-to-bottom starting at 1
- All sprites must be same size (spriteW x spriteH)
Mouse Input (Graphics Mode Only)
| Function | Description |
|---|---|
MOUSEX / MOUSEY |
Cursor position |
MOUSEB |
Button state (bitmask, use AND) |
Button constants: MOUSE_LEFT#=1, MOUSE_RIGHT#=2, MOUSE_MIDDLE#=4
Color Palette (0-15)
| 0 Black | 4 Red | 8 Dark Gray | 12 Light Red |
|---|---|---|---|
| 1 Blue | 5 Magenta | 9 Light Blue | 13 Light Magenta |
| 2 Green | 6 Brown | 10 Light Green | 14 Yellow |
| 3 Cyan | 7 Light Gray | 11 Light Cyan | 15 White |
Performance Tips
- Use
SCREENLOCK ON/OFFfor all animation LINE...BFis faster thanCLSfor clearing- Store
RGB()values in constants - REMOVESHAPE unused shapes
- SLEEP 16 for ~60 FPS
- Do math/logic outside SCREENLOCK block
Built-in Constants
Arrow Keys
KEY_UP# |
KEY_DOWN# |
KEY_LEFT# |
KEY_RIGHT# |
Special Keys
KEY_ESC# |
KEY_TAB# |
KEY_BACKSPACE# |
KEY_ENTER# |
KEY_SPACE# |
KEY_INSERT# |
KEY_DELETE# |
KEY_HOME# |
KEY_END# |
KEY_PGUP# |
KEY_PGDN# |
Modifier Keys
KEY_LSHIFT# |
KEY_RSHIFT# |
KEY_LCTRL# |
KEY_RCTRL# |
KEY_LALT# |
KEY_RALT# |
KEY_LWIN# |
KEY_RWIN# |
Function Keys
KEY_F1# |
KEY_F2# |
KEY_F3# |
KEY_F4# |
KEY_F5# |
KEY_F6# |
KEY_F7# |
KEY_F8# |
KEY_F9# |
KEY_F10# |
KEY_F11# |
KEY_F12# |
Numpad Keys
KEY_NUMPAD0# |
KEY_NUMPAD1# |
KEY_NUMPAD2# |
KEY_NUMPAD3# |
KEY_NUMPAD4# |
KEY_NUMPAD5# |
KEY_NUMPAD6# |
KEY_NUMPAD7# |
KEY_NUMPAD8# |
KEY_NUMPAD9# |
Punctuation Keys
KEY_COMMA# |
KEY_DOT# |
KEY_MINUS# |
KEY_EQUALS# |
KEY_SLASH# |
KEY_BACKSLASH# |
KEY_SEP# |
KEY_GRAVE# |
KEY_LBRACKET# |
KEY_RBRACKET# |
Alphabet Keys
KEY_A# |
KEY_B# |
KEY_C# |
KEY_D# |
KEY_E# |
KEY_F# |
KEY_G# |
KEY_H# |
KEY_I# |
KEY_J# |
KEY_K# |
KEY_L# |
KEY_M# |
KEY_N# |
KEY_O# |
KEY_P# |
KEY_Q# |
KEY_R# |
KEY_S# |
KEY_T# |
KEY_U# |
KEY_V# |
KEY_W# |
KEY_X# |
KEY_Y# |
KEY_Z# |
Number Keys
KEY_0# |
KEY_1# |
KEY_2# |
KEY_3# |
KEY_4# |
KEY_5# |
KEY_6# |
KEY_7# |
KEY_8# |
KEY_9# |
Mouse
MOUSE_LEFT# = 1, MOUSE_RIGHT# = 2, MOUSE_MIDDLE# = 4
Logical
TRUE = 1, FALSE = 0
Source Control
INCLUDE
INCLUDE "other_file.bas" ' Insert source at this point
INCLUDE "MathLib.bb" ' Include compiled library
Libraries (.bb files)
' MathLib.bas — can ONLY contain DEF FN functions
DEF FN add$(x$, y$)
RETURN x$ + y$
END DEF
Compile: bazzbasic.exe -lib MathLib.bas → MathLib.bb
INCLUDE "MathLib.bb"
PRINT FN MATHLIB_add$(5, 3) ' Auto-prefix: FILENAME_ + functionName
- Libraries can only contain
DEF FNfunctions - Library functions can access main program constants (
#) - Version-locked: .bb may not work across BazzBasic versions
Common Patterns
Game Loop
SCREEN 12
LET running$ = TRUE
WHILE running$
LET key$ = INKEY
IF key$ = KEY_ESC# THEN running$ = FALSE
' Math and logic here
SCREENLOCK ON
LINE (0,0)-(640,480), 0, BF ' Fast clear
' Draw game state
SCREENLOCK OFF
SLEEP 16
WEND
END
HTTP + Data
DIM response$
LET response$ = HTTPGET("https://api.example.com/scores")
PRINT response$
DIM payload$
LET payload$ = HTTPPOST("https://api.example.com/submit", "{""score"":9999}")
PRINT payload$
Save/Load with Arrays
DIM save$
save$("level") = 3
save$("hp") = 80
FileWrite "save.txt", save$
DIM load$
LET load$ = FileRead("save.txt")
PRINT load$("level") ' Output: 3
Sound with Graphics
SCREEN 12
LET bgm$ = LOADSOUND("music.wav")
LET sfx$ = LOADSOUND("jump.wav")
SOUNDREPEAT(bgm$)
WHILE INKEY <> KEY_ESC#
IF INKEY = KEY_SPACE# THEN SOUNDONCE(sfx$)
SLEEP 16
WEND
SOUNDSTOPALL
END
Code Style Conventions
Variables — camelCase$
LET playerName$ = "Hero"
LET score$ = 0
Constants — UPPER_SNAKE_CASE#
LET MAX_HEALTH# = 100
LET SCREEN_W# = 640
Arrays — camelCase$ (like variables, declared with DIM)
DIM scores$
DIM playerData$
User-defined functions — PascalCase$
DEF FN CalculateDamage$(attack$, defence$)
DEF FN IsColliding$(x$, y$)
Labels — descriptive names, [sub:] prefix recommended for subroutines
[sub:DrawPlayer] ' Subroutine
[gameLoop] ' Jump target
Program Structure
- Constants first
- User-defined functions (or INCLUDE them)
- Main program loop
- Subroutines (labels) last
Subroutine Indentation
[sub:DrawPlayer]
MOVESHAPE player$, x$, y$
DRAWSHAPE player$
RETURN