by Megastyle
Version 1.0.0
Created by Chris Stanley / Megastyle 2026
Disco Volante is a Windows desktop tool for Commodore 64 developers. It converts standard image files into C64-compatible bitmap graphics, handling the technical constraints of the C64’s colour hardware automatically while giving you fine-grained control over the results.
Output files are byte-compatible with Koala Painter (.koa) and Art Studio (.art), and can be loaded directly into assembler projects or tested in an emulator such as VICE.
GRAPHICS MODES
Multicolour bitmap: 160×200 effective pixels, up to 4 colours per 8×8 cell, saved as Koala Painter (.koa)
Hi-Res bitmap: 320×200 pixels, 2 colours per 8×8 cell, saved as Art Studio (.art)
Hi-Res Monochrome: 320×200 pixels, two freely chosen C64 palette colours, saved as Disco Volante Mono (.mon)
MAIN FEATURES
Source image preparation
* Load common image formats (JPEG, PNG, BMP, GIF, WEBP, TIFF)
* Drag and drop images directly onto the source pane
* Rotate source image 90 degrees left or right
* Zoom source display from 100% down to 20% with manual entry box
* Adjustable source crop box (correct C64 aspect ratio maintained)
* Crop box can extend into blank canvas areas; blank regions become
* zero bytes in the bitmap (displayed as background colour on the C64)
Conversion controls
* Dithering: None, Ordered (Bayer 8×8), Floyd-Steinberg, Atkinson
* Dithering strength slider
* Colour matching: RGB or Perceptual (CIE Lab)
* Pre-processing: Brightness, Contrast, Saturation
* Cell strategy (Multicolour): Frequency, Luminance, Contrast, Error-Min
* Configurable load address for .koa and .art files
* Restore Defaults button to reset all conversion parameters in one click
Multicolour features
* Background colour auto-selected or manually overridden via palette picker (only colours present in the image are available to select)
* Monochrome features
* Freely selectable foreground and background colours from the C64 palette
* Luminance-based dithering — pixel pattern is stable when colours are changed
* Invert image checkbox
* Fill colour byte displayed above preview (the Screen RAM value to POKE
Preview
* Real-time C64 bitmap preview
* Optional C64 border simulation with selectable border colour
* Cell grid overlay showing 8×8 character cell boundaries
* CRT emulation (scanlines + horizontal phosphor blur)
* Pixel zoom magnifier (6x) with cell grid support
Loading and saving
* Save Bitmap: exports full image in the appropriate format
* Save Preview PNG: saves the C64 preview pane as a PNG
* Load Bitmap: load a previously saved .koa, .art or .mon file directly into the preview pane for cropping or colour remapping without re-converting from source
* Loaded .mon files support instant Invert and FG/BG colour changes without re-conversion (direct bit-pattern manipulation)
Output crop export
* Selectable crop region on the C64 preview (draggable corner handles, snaps to 8-pixel cell boundaries)
* Exports sub-region as a compact binary for direct use in assembler projects
General
* Searchable help pages covering all features
* Remembers last used folder between sessions
* Fully self-contained Windows executable — no installation required
FILE FORMATS
.koa: Koala Painter multicolour — 10,003 bytes
Load address (2) + bitmap (8,000) + screen RAM (1,000) + colour RAM (1,000) + background byte (1)
.art: Art Studio hi-res — 9,002 bytes
Load address (2) + bitmap (8,000) + screen RAM (1,000)
.mon: Disco Volante monochrome — 8,001 bytes
Fill colour byte (1) + bitmap (8,000)
The fill colour byte encodes FG (hi nibble) and BG (lo nibble) and is the value to write to every Screen RAM location ($0400-$07E7) to reproduce the chosen colours on a real C64.
All formats store bitmap data in cell-major, line-minor order: for each of the 1,000 cells (40 columns x 25 rows), 8 bytes of row data.
Download, here
