Mandelbrot Upic v1.0.0

First feature-complete release of Mandelbrot Upic -- a Mandelbrot fractal generator and interactive pan/zoom viewer for the Commodore 64 Ultimate. Confirmed working on real Ultimate 64 Elite 2 hardware across multiple power cycles. Watch it in action.

Highlights

• On-device fractal generation at 64 MHz turbo -- fixed-point (Q5.11) escape-time iteration, a quarter-square multiply table, and a cardioid/period-2-bulb early-skip. See docs/MANDELBROT_ALGORITHM.md.
• Live picture build-up -- the fractal displays column by column as it generates, not just once complete.
• Upic border-color raster display (384x256, 16 colors) -- no bitmap mode, no sprites, just cycle-exact border-color changes. See docs/UPIC_VIEWER.md.
• Interactive pan and zoom: browse mode (WASD/cursor panning, gradual zoom-out) and box mode (move/resize a selection box, confirm to zoom in), with corner markers drawn directly into the picture buffer. See docs/ZOOM_FEATURE.md.
• 4 selectable color gradients (default, fire, ice, rainbow), cycled live without leaving the current view.
• Auto-loading Ultimate 64 Elite 2 config -- enables the Command Interface and U64 turbo registers this demo needs, no manual setup step.

See CHANGELOG.md for the full feature list.

Getting started

Requires firmware 3.15 or newer -- in practice an Ultimate 64 Elite 2 for now, since the corresponding C64U firmware hasn't been released yet. See the README's Installation section.

Release assets

• mandelupic-v1.0.0-<timestamp>.zip -- the full release archive: mandelupic.prg, the auto-loading mandelupic.cfg, and a README.md copy, ready to extract straight onto your Ultimate's SD/USB storage.
• Source code (zip / tar.gz) -- GitHub's automatic archive of this tag.

Documentation

Full architecture, algorithm, display-technique, and zoom-feature manuals live in docs/ -- see the README's Documentation section for the complete index.