# MUD64 Native Compile (MUD64CMP)



> Compile `.mud` **on the Commodore 64** — same IR as [Code Designer Flight Deck](../MUD64-SPEC.md#54-dual-compile--code-designer-or-native-c64).



## Overview



| Component | Role |

|-----------|------|

| **MUD64CMP** | On-disk 6510 compiler (`LOAD"MUD64CMP",8,1`) |

| **MUD64.LIB** | Runtime: frame router, PETSCII plotter, raycast engine, optional sprite mux |

| **MODULE.MUD** | Your source (plain PETSCII text, 40-col safe) |

| **MODULE.PRG** | Output — autostart or `SYS` entry |



Code Designer and native compile share **MUD64-IR**: frame graph, `++ c64.*` manifests, PETSCII plot opcode stream, **raycast opcode stream**.



## Quick start (real hardware)



```

LOAD"MUD64CMP",8,1

RUN

INPUT"MODULE NAME";N$

OPEN 1,8,0,N$+".MUD":REM read source

... compiles to MODULE.PRG ...

SAVE"MODULE",8:REM or autostart D64

```



## Memory map (default PAL)



| Region | Address | Contents |

|--------|---------|----------|

| BASIC load | `$0801` | Generated PRG |

| Plotter | `$0C00` | `PLOT_*` routines from `++ c64.petscii` |

| **Raycast engine** | `$1000` | `RAYCAST_*` cast + blit from `++ c64.raycast` |

| Frame table | `$2000` | Branch vectors + text pointers |

| **Maze grids** | `$2800` | Level map bytes (max 16×16 × 4 levels typical) |

| Screen | `$0400` | PETSCII semigraphics output (40×25) |

| **Z-buffer / color LUT** | `$2A00` | Per-column depth + VIC fg/bg indices |

| **Trig LUT** | `$C000` | sin/cos 256-entry 8.8 fixed (shared with `++ c64.math`) |

| Mesh LUT | `$C200` | Optional REU / expanded RAM for 3D precalc |



## PETSCII plot opcodes (native)



Same opcodes CD emits — see MUD64-SPEC §5.4:



- `PLOT_CLEAR` · `PLOT_LINE` · `PLOT_CIRCLE` · `PLOT_TUNNEL` · `PLOT_MESH`



## Raycast opcodes (native)



Same opcodes CD emits — see MUD64-SPEC §10.6:



| Opcode | Args | Notes |

|--------|------|-------|

| `RAYCAST_INIT` | cols, rows, fov | Viewport + LUT ptr |

| `RAYCAST_MAP` | level_id, w, h, data_ptr | Maze @ `$2800` |

| `RAYCAST_TEXTURE` | wall_type, pattern_ptr | Stone / metal / hell patterns |

| `RAYCAST_SPAWN` | level_id, px, py, pa | 8.8 fixed player vector |

| `RAYCAST_SPRITE` | id, x, y, art_ptr | Billboard imp |

| `RAYCAST_WALK` | mode, speed, turn | `auto` or input IRQ |

| `RAYCAST_FRAME` | frame_id, scene_name | Frame graph bind |



**Compile include:** add `++ c64.raycast` to `++ c64.compile` `cd:` / `native:` manifest (alongside `++ c64.petscii`).



Reference module: [`examples/mud-doom-demo.mud`](../examples/mud-doom-demo.mud) → `out/MUDDOOM.PRG`.



## Verify dual build (Team DC QA)



When `++ c64.compile target=both`:



1. Export from Flight Deck → `out/MODULE.PRG`

2. Compile on C64 → `MODULE.PRG` on disk

3. Compare SHA256 in covenant manifest (optional `VERIFY both` flag)



Mismatch → check `machine: c64pal` vs `c64ntsc` raster tables.



## Roadmap



- [ ] MUD64CMP v0.1 tokenizer (6510)

- [ ] PETSCII plotter ROM @ `$0C00`

- [ ] **Raycast engine ROM @ `$1000`** (fixed-point cast + PETSCII blit)

- [ ] Flight Deck export parity test suite (plot + raycast IR)

- [ ] `.D64` with MUD64CMP + MUDDOOM module for demo parties



**FutureVision Labs · Team DC · [homebrewz.live](https://homebrewz.live)**