Blossom
Games & Classics
Barry Martin's Hopalong strange attractor, rendered live on the Super Nintendo and
flown around with the joypad — written in C and compiled to a real .sfc ROM with
the llvm-mos-based 65816 toolchain. The
attractor accumulates into a hit-count grid in WRAM and shows through Mode 7, with the
parameter panel spliced in by an HDMA mode-switch.
← ↑ ↓ → pan · Q/W zoom · X/A attractor · Shift colour · Enter reset
Click the screen, then play. It blooms in over ~10 s, then shimmers — tab away and it pauses.
Controls
| Keys | Action |
|---|---|
| ← ↑ ↓ → | Pan the view |
| Q / W | Zoom out / in |
| X / A | Next / previous attractor |
| Shift | Cycle colour mode |
| Enter | Reset view + attractor |
The three attractors
Cycle them with X (next) / A (previous) — each is a distinct bounded Hopalong shape; switching re-blooms the cloud (~10 s).
| Name | a | b | c |
|---|---|---|---|
| CLASSIC | 7.17 | 8.44 | 2.56 |
| DENSE | 2.00 | 5.00 | 1.00 |
| BLOOM | −2.00 | 7.00 | 5.00 |
Tips
- The bloom is the point. After boot or an attractor switch the cloud fills in over ~10 s; once it's in, the motion is the palette shimmer.
- Zoom pivots on the attractor (Q/W), so it stays put as you zoom; the D-pad slides it around and Enter snaps back.
- Colour modes (Shift) rotate where the hue wheel starts — the shape is unchanged.
Built in C with an LLVM/65816 SNES toolchain, verified pixel-for-pixel against
two emulators. The player above is that exact cycle-accurate core — hit Verify fidelity
to reproduce the build gate's WRAM assert (grid hash 0x9047) live in this tab.