# Disassembly Project 1

This is a set of disassembled NES roms using AI to translate.

This is not for distribution.
This is not for you.

> **Layout changed 2026-10-20:** projects moved into **mapper directories**
> (`NROM/`, `AOROM/`, `CNROM/`, `MMC1/`, `MMC3/`, `MMC5/`, `UNROM/`), project
> folders were **flattened** (the old `copilot/` subfolder is gone — everything
> sits directly in the project folder), every project's `OVERVIEW.md` became its
> `README.md`, and a root `Makefile` now builds and verifies all projects at once
> (`make`, `make clean`, `make <MAPPER>`); the git pre-commit hook drives it.
> Older docs, commit messages and paths in this file's per-project notes may
> still reference the previous layout — mentally strip the `copilot/` prefix.

# Disassembly Project Index — /home/tmerritt/Projects/disasm/

This document provides a consolidated overview of the **promoted** NES disassembly projects in the repository. Projects are organized **by mapper** into a folder per project under `NROM/`, `AOROM/`, `CNROM/`, `MMC1/`, `MMC3/`, `MMC5/` or `UNROM/` — everything here so far is mapper 0, so all promoted projects live in `NROM/`. The pre-promotion tier mirrors the structure under `_wip/<MAPPER>/<Project>/` and is documented separately in **`WIP.md`** (857 projects across 30 mapper folders). Each project folder is **flat**: the source (`prg.s`, plus `header.s`/`chr.s` where present), the build config (`linker.cfg`, `symbols.inc`, `locals.inc`, `Makefile`) and the ROM splits all sit directly in the folder. Each project carries its own `README.md` (the file was called `OVERVIEW.md` before 2026-10-20) with a detailed power-on execution flow analysis.

---

## Project Inventory

**Mirroring** is the iNES *arrangement* value taken from header byte 6, bit 0 (`0` = Horizontal, `1` = Vertical), the convention `AGENTS.md` fixes. Several per-project README files (then named `OVERVIEW.md`) previously carried the opposite *mirroring-direction* wording; all were normalized to this column on 2026-10-19.

| # | Project | Region/Version | PRG Size | CHR Size | Mirroring | Build Status | Vectors (NMI / RESET / IRQ) |
|---|---------|----------------|----------|----------|-----------|--------------|------------------------------|
| 1 | Balloon Fight (JU) | Japan | 16 KB | 8 KB | Horizontal | BYTE-IDENTICAL (Pass complete) | $C094 / $C000 / $C0F7 |
| 2 | Baseball (UE) | USA/Europe | 16 KB | 8 KB | Horizontal | BYTE-IDENTICAL (Pass complete) | $C046 / $C40B / $C43E |
| 3 | Bomberman (U) | USA | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass complete) | $C01A / $C000 / $FFF9 |
| 4 | Burger Time (U) | USA | 16 KB | 8 KB | Horizontal | BYTE-IDENTICAL (Pass complete) | $FF7F / $FD24 / $FD24 |
| 5 | Clu Clu Land (JU) | Japan | 16 KB | 8 KB | Horizontal | BYTE-IDENTICAL (Pass complete) | $C1F1 / $C196 / $C196 |
| 6 | Defender 2 (U) | USA | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass complete) | $CAA1 / $C983 / $CA9E |
| 7 | Excitebike (JU) | Japan | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass complete) | $C23B / $C184 / $FFF0 |
| 8 | Tennis (JU) | Japan | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass complete) | $C07D / $C000 / $C000 |
| 9 | Pac-Man (USA) (Namco) | — | 16 KB | 8 KB | Horizontal | BYTE-IDENTICAL (Pass complete) | $C10E / $C033 / $C17E |
| 10 | Donkey Kong 3 (JUE) | Japan / USA / Europe | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass complete) | $C08D / $C000 / $C000 |
| 11 | Donkey Kong Jr. (JU) | Japan | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass complete) | $C6E6 / $C66E / $FFF0 |
| 12 | CIRCUS | — | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass complete) | $C05A / $C000 / $4CB7 |
| 13 | Wild Gunman (U) | USA | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass 3 complete, 49.3% code) | $C086 / $C000 / $C000 |
| 14 | Joypad Test Cartridge (U) | USA | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass 3 complete) | $CCF7 / $C000 / $C000 |
| 15 | NES PowerPad Test Card (U) | USA | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass complete) | $E06E / $E000 / $E000 |
| 16 | MUSCLE (U) | USA | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass complete) | $86CB / $8000 / $8764 |
| 17 | Lunar Pool (U) | USA | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass 2 complete, Pass 3 tables named) | $FF65 / $E80C / $FF64 |
| 18 | Donkey Kong (JU) | Japan | 16 KB | 8 KB | Horizontal | BYTE-IDENTICAL (Pass 2/3 complete, 76.3% code) | $C85F / $C79E / $FFF0 |
| 19 | **Donkey Kong Jr. Math (U)** | USA | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 3 complete)** | $C4A9 / $C41E / $FFF0 |
| 20 | **Duck Hunt (JUE)** | Japan / USA / Europe | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 3 complete)** | $C086 / $C000 / $C000 |
| 21 | **Ice Climber (JE)** | — | 16 KB | 8 KB | Horizontal | **BYTE-IDENTICAL (Pass 3 complete)** | $C076 / $C014 / $FFF0 |
| 22 | **Ice Climber (U)** | USA | 16 KB | 8 KB | Horizontal | **BYTE-IDENTICAL (Pass 3 complete)** | $C076 / $C014 / $FFF0 |
| 23 | **Lode Runner (U)** | USA | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 2/3 complete)** | $C02C / $C000 / $FFF9 |
| 24 | **Pinball (JU)** | Japan | 16 KB | 8 KB | Horizontal | **BYTE-IDENTICAL (Pass 2/3 complete)** | $C1ED / $C000 / $C1ED |
| 25 | **Millipede (U)** | USA | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 2/3 complete, 74.6% code)** | $C7F1 / $C735 / $FFF0 |
| 26 | **Popeye (JU) (PRG 0)** | — | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 2/3 complete, 72.3% code)** | $C701 / $C649 / $FFF0 |
| 27 | **Popeye (JU) (PRG 1)** | — | 16 KB | 8 KB | Horizontal | **BYTE-IDENTICAL (Pass 2/3 complete, 72.3% code; promoted from `_wip` 2026-10-20)** | $C701 / $C649 / $FFF0 |
| 28 | `Golf (JU)` | Japan | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 1+ substantial; whole-ROM compare added 2026-10-20)** | $C0A6 / $C000 / $C0C4 |
| 29 | **Hogan's Alley (JU)** | Japan | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 2 complete, Pass 3 partial, 49.1% code; promoted 2026-10-20)** | $C088 / $C000 / $C000 |
| 30 | **Mario Bros (JU)** | Japan | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 2 complete, Pass 3 partial, 78.4% code; promoted 2026-10-20)** | $C07D / $C000 / $C000 |
| 31 | `Pac-Man (Tengen) (U)` | USA | 16 KB | 8 KB | Horizontal | **BYTE-IDENTICAL (Pass 2 complete, Pass 3 partial, 20.0% code; promoted 2026-10-20)** | $C0FA / $C033 / $C16A |
| 32 | `Pac-Man (U)` | USA | 16 KB | 8 KB | Horizontal | **BYTE-IDENTICAL (Pass 2 complete, Pass 3 partial, 19.6% code; promoted 2026-10-20)** | $C0FA / $FF00 / $C16A |
| 33 | `Pyramid (U)` (Sachen) | — | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 2 complete, Pass 3 partial, 39.6% code; promoted 2026-10-20)** | $D72E / $FF00 / $FF00 |
| 34 | `Raid on Bungeling Bay (U)` | USA | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 2/3 partial, 64.6% code; promoted 2026-10-20)** | $C04C / $C000 / $C2C0 |
| 35 | `Raid on Bungeling Bay (U) [a2]` | — | 16 KB | 8 KB | Horizontal | **BYTE-IDENTICAL (Pass 2 complete, Pass 3 partial, 64.3% code; promoted 2026-10-20)** | $C04C / $C000 / $C2C0 |
| 36 | Urban Champion (JU) | Japan | 16 KB | 8 KB | Vertical | **BYTE-IDENTICAL (Pass 3 complete, 33.9% code)** | $CA91 / $CA00 / $CA00 |

All 36 are mapper 0 / 16 KB PRG / 8 KB CHR, no trainer.

Rows 1-27, row 29 (`Hogan's Alley (JU)`, promoted 2026-10-20), row 30
(`Mario Bros (JU)`, promoted 2026-10-20), row 31
(`Pac-Man (Tengen) (U)`, promoted 2026-10-20), row 32
(`Pac-Man (U)`, promoted 2026-10-20), row 33 (`Pyramid (U)`, promoted
2026-10-20), row 34 (`Raid on Bungeling Bay (U)`, promoted 2026-10-20), row 35
(`Raid on Bungeling Bay (U) [a2]`, promoted 2026-10-20) and row 36 are
promoted. Row 28 (`Golf (JU)`) is still in `_wip/` but now also verifies
**BYTE-IDENTICAL**: its whole-ROM compare was added 2026-10-20, so the header
and CHR are proven for it too. All 36 rows in this table are therefore
**BYTE-IDENTICAL** — `make` compares the whole reconstructed ROM against
`rom.nes` in the project folder.
(Urban Champion, row 36, kept its tail number so the tier split is no longer a
single contiguous range.)

> **Still true after the 2026-10-20 reorganization.** The mapper reorganization moved
> `Donkey Kong Jr. Math (U)` (row 19) into `_wip/NROM/` — it was fixed the same day (its four
> `jsr $F218` call sites had been labelled `SubCF218_Block` = $F1DC; repointed to
> the true entry `SubCF218`) and promoted back into `NROM/`. **Popeye (JU) (PRG 1)**
> was promoted from `_wip/NROM/` the same day (row 27) — its whole-ROM compare passes
> on the first build. `Excitebike (JU)` (row 7) — the repo's one open block after
> being returned to `NROM/` with a broken mid-repair build (duplicate symbol) —
> was finished the same day: the byte-596 mismatch (`$0A` operands where the ROM
> uses `$11`, now aliased `NmiMaskShadow`) is fixed, the 4,401 damaged audit
> comments were re-anchored via `_tools/repair_audit_comments.py`, and 58 raw
> `jsr/jmp $XXXX` operands were substituted with labels/equates. **All 35
> projects under `NROM/` now verify byte-identical.**

**How to read this table.** The vectors are the three little-endian words at the **end of the
16 KB PRG** (`$FFFA-$FFFF` in the `$C000` mirror) — *not* fields in the iNES header, whose bytes
0-9 carry only sizes, mirroring and mapper. Regenerate the whole column with:

```bash
python3 - <<'EOF'
import os
MAPPERS = ('NROM', 'AOROM', 'CNROM', 'MMC1', 'MMC3', 'MMC5', 'UNROM')
for base in MAPPERS:
    if not os.path.isdir(base):
        continue
    for p in sorted(d for d in os.listdir(base) if os.path.isdir(os.path.join(base, d))):
        rom = open(f"{base}/{p}/rom.nes", 'rb').read()
        prg = rom[16:16 + rom[4]*16384]; vo = len(prg) - 6
        v = [prg[vo+i] | (prg[vo+i+1] << 8) for i in (0, 2, 4)]
        print(f"{p:30s} {'Vertical' if rom[6] & 1 else 'Horizontal':10s} "
              + " / ".join("$%04X" % x for x in v))
EOF
```

Five rows were wrong before this pass, all from copy-paste duplication of a neighbouring row's
vectors, and are corrected above:

| Project | Was | Actually |
|---------|-----|----------|
| Burger Time (U) | `$C046 / $C40B / $C43E` (Baseball's) | `$FF7F / $FD24 / $FD24` |
| Clu Clu Land (JU) | `$C1F1 / $C000 / $FFF9` | `$C1F1 / $C196 / $C196` |
| Excitebike (JU) | `$C1F1 / $FD24 / $FD24` | `$C23B / $C184 / $FFF0` |
| Pac-Man (USA) (Namco) | `$C10E / $C000 / $C17E` | `$C10E / $C033 / $C17E` |
| Donkey Kong 3 (JUE) | `$C07D / $C000 / $C000` | `$C08D / $C000 / $C000` |

Donkey Kong Jr.'s mirroring was also wrong (Horizontal, actually Vertical). Odd vector *targets*
are not mistakes: Burger Time's `$FF7F` NMI and CIRCUS's `$4CB7` IRQ point into unused/data space,
which is common in this set — see "Notes" under Per-Project Details.

Region/Version comes from the folder-name suffix (JU/U/UE/JUE); these mapper-0 headers do not
encode region, so CIRCUS — whose folder carries no suffix — is left as `—` rather than guessed.

---

## Per-Project Details

### 1. Balloon Fight (JU)
- **Folder:** `NROM/Balloon Fight (JU)/`
- **ROM:** `balloon.nes` (24,592 bytes)
- **Source:** `prg.s` (8,543 lines)
- **Linker:** PRG at $C000, 16 KB; single segment
- **Vectors:** NMI → $C094 (`NmiHandler`), RESET → $C000 (`Reset`), IRQ → $C0F7 (`IrqHandler`, self-loop)
- **Key subsystems:** NMI-driven frame loop with PPU command buffer, round spawner ($C790), bonus objects ($CB74), carrier/rescue sequence ($C6F9), particle system ($CDAA), sound driver ($FFF7 banked)
- **Build fix:** None needed; byte-identical out of the box. **Pass 1 verified complete 2026-10-16** — 5,303 instructions / 11,260 code bytes (68.7%), which is *more* than the complete-opcode static tracer finds (5,277 / 11,202); the 166 tracer-only bytes are genuine data (command scripts at $D437/$D45A, the $C3B5 pointer table, the arithmetic table at $FBCA), not missed code. The last two `.incbin` spans were converted to explicit classified bytes (`TrailingFillBeforeApuTables` at $F4C5, `SoundEngineTailBytes` at $F5FC), so no ROM byte is hidden
- **Pass 3 symbols (2026-10-19):** every operand `symbols.inc`/`locals.inc` defines is now
  named in `prg.s` — **125** hardware-register operands and **797 of 813** zero-page/RAM
  operands. The 15 multi-alias addresses were resolved per routine (`--sites` in
  `_tools/apply_symbols.py`). **16** operands are left numeric: `$13` used as a plain
  high-byte scratch beside `Temp12`, where none of its three aliases fits. Rebuild stays
  byte-identical.
- **Details:** `Balloon Fight (JU)/README.md`

### 2. Baseball (UE)
- **Folder:** `NROM/Baseball (UE)/`
- **ROM:** `baseball.nes` (24,592 bytes)
- **Source:** `prg.s` (21,624 lines — largest source)
- **Linker:** PRG at $C000, 16 KB; single segment
- **Vectors:** NMI → $C046 (`NMI`), RESET → $C40B (`Reset`), IRQ → $C43E (`IRQ`, `rti`)
- **Key subsystems:** Queued event system ($EB66–$EB9C) as the main frame driver, round/state machine ($C5FE), batting/pitching ($C6044–$C6414), object sorting ($C339), sound driver ($F9D0–$FE2x)
- **Build fix:** None needed; byte-identical out of the box
- **Pass 3 symbols (2026-10-19):** **121 operands substituted** (85 single-name + 36 hardware) from `symbols.inc`/`locals.inc` via `_tools/apply_symbols.py` — zero residue. Rebuild stays byte-identical.
- **Details:** `Baseball (UE)/README.md`

### 3. Bomberman (U)
- **Folder:** `NROM/Bomberman (U)/`
- **ROM:** `bomberman.nes` (24,592 bytes)
- **Source:** `prg.s` (7,553 lines), `header.s`, `chr.s`
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C01A (`NmiHandler`), RESET → $C000 (`Reset`), IRQ → $FFF9 (`IrqHandler`, `rti`)
- **Key subsystems:** NMI-driven PPU command queue and VRAM transfers, main loop at $C368 with state dispatch table ($C75D), bomb/object slots (80 slots at $03E6), sound driver ($E642–$FE2x) with dispatch table ($E6AD)
- **Build fix:** One-byte mismatch at CPU $E71B (`dec $E4` vs `dec $54`) — resolved by adding `RandomStateAlt = $E4` to `locals.inc` alongside `RandomState0 = $54` (zero-page reuse); also renamed `ControllerState` → `ControllerState1`, `Main_HandleControl_C368` → `MainGameLoop`, `Gameplay_HandleControl_C79D` → `GameplayUpdate`, `Sound_HandleControl_E65F` → `SoundUpdate`
- **Pass 3:** Applied 354 single-name + 8 site-resolved multi-alias operands from `locals.inc`; 24 in-file table labels from `reconstructed.lbl`; 0 hardware substitutions needed. Residue: 758 unnamed operands (179 distinct addresses).
- **Details:** `Bomberman (U)/README.md`

### 4. Burger Time (U)
- **Folder:** `NROM/Burger Time (U)/`
- **ROM:** `Burger Time (U) [!].nes` (24,592 bytes)
- **Source:** `prg.s` (9,323 lines), `header.s`, `chr.s`
- **Linker:** HEADER, PRG at $C000 (0x3FFA), VECTORS at $FFFA, CHR
- **Vectors:** NMI → $FF7F (points *into* the vector page itself — not a real handler; NMI is effectively unused), RESET → $FD24 (`ResetHandler`, `sei` prologue), IRQ → $FD24 (reuses Reset)
- **Key subsystems:** Event-driven main loop via `CommonEngineExit` ($EB6A) and queued events ($EB9D), title screen / round state machine ($C5FE), object arrays ($03E6 state, $0436/$0486 position), audio engine ($F9D0–$FE2x) with music sequencer ($FD34)
- **Build fix:** None needed; byte-identical. Requires symlink `burger_time.nes → "../Burger Time (U) [!].nes"` due to spaces in ROM filename
- **Details:** `Burger Time (U)/README.md`

### 5. Clu Clu Land (JU)
- **Folder:** `NROM/Clu Clu Land (JU)/`
- **ROM:** `rom.nes` (24,592 bytes)
- **Source:** `prg.s` (9,151 lines)
- **Linker:** PRG at $C000, 16 KB; single segment (no separate HEADER/CHR segments in cfg, but CHR data is embedded inline at end of prg.s)
- **Vectors:** NMI → $C1F1 (`NMIHandler`), RESET → $C196 (`ResetEntry`, shared with the IRQ handler), IRQ → $C196 (`IrqHandler`, reuses Reset)
- **Key subsystems:** State-machine main loop via dispatch table at $C000–$C00D, NMI-driven PPU command queue + VRAM transfers, object pools ($03E6 state, $0436/$0486 position), sound driver ($E642–$F7C0) with dispatch table ($E6AD)
- **Build fix:** One `bpl` branch to undefined label at CPU $FAB4 — replaced with `bne *-$1B` to produce original `d0 e3` bytes (disassembler mislabeled `bne` as `bpl`)
- **Details:** `Clu Clu Land (JU)/README.md`

### 6. Defender 2 (U)
- **Folder:** `NROM/Defender 2 (U)/`
- **ROM:** `Defender 2 (U).nes` (24,592 bytes)
- **Source:** `prg.s` (11,905 lines)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (0x3FFA), VECTORS at $FFFA, CHR at $0000
- **Vectors:** NMI → $CAA1 (`NmiHandler`), RESET → $C983 (`ResetHandler`), IRQ → $CA9E (`IrqHandler`, reuses Reset)
- **Key subsystems:** Event-driven main loop (`UpdateSideScrollingGameplay_CA6A` at $CA6A) waiting on NMI flag, side-scrolling gameplay ($C073–$C324 family), PPU streaming ($F20B–$F7C0), audio engine ($E642–$F7C0) with dispatch table ($E6AD)
- **Build fix:** Same `bpl` → `bne *-$1B` fix at CPU $E811 as Clu Clu Land (disassembler mislabeled `bne` as `bpl`)
- **Details:** `Defender 2 (U)/README.md`

### 7. Excitebike (JU)
- **Folder:** `NROM/Excitebike (JU)/`
- **ROM:** `rom.nes` (24,592 bytes)
- **Source:** `prg.s` (13,992 lines)
- **Linker:** PRG at $C000, 16 KB; single segment
- **Vectors:** NMI → $C23B (`NMI`), RESET → $C184 (`Reset`), IRQ → $FFF0 (points into audio data region — likely placeholder/unused)
- **Key subsystems:** NMI-driven state machine with dispatch table at $C000–$C00D (14 states), title/menu system ($C346–$C454), gameplay update chain ($C99A), race update ($C8D6), audio engine ($F8DE) with 4 channels + SFX, serial I/O over controller port $4016
- **Build fix:** Same `bpl` → `bne *-$1B` fix at CPU $FAB4 (same pattern as Clu Clu Land/Defender 2). On 2026-10-20 the last whole-ROM mismatch (byte 596) was fixed — two NMI operands the ROM spends on `$11`, a second PPU-mask shadow, were emitted with `PpuMaskShadow` (`$0A`); `$11` is now aliased `NmiMaskShadow` in `locals.inc`. The same day the audit trail was re-anchored from the ca65 listing via `_tools/repair_audit_comments.py` (6,339 shifted comments + 4,401 doubled-`??` forms) and all 58 raw `jsr/jmp $XXXX` operands were substituted with routine labels/`locals.inc` sub-entry equates.
- **Details:** `Excitebike (JU)/README.md`

### 8. Tennis (JU)
- **Folder:** `NROM/Tennis (JU)/`
- **ROM:** `Tennis (JU).nes` (24,592 bytes)
- **Source:** `prg.s` (9,268 lines)
- **Linker:** PRG at $C000, 16 KB; single segment
- **Vectors:** NMI → $C07D (`NmiHandler`), RESET → $C000 (`Reset`), IRQ → $C000 (`Reset` reused)
- **Key subsystems:** NMI-synchronized main loop (`MainLoop` at $C04F), game state machine via `MainStateHandlerTable` ($C101, 12 states), game mode state machine via `GameModeStateTable` ($CAD7, 8 states), object/sprite system with fixed-point physics, audio engine ($F8DE) with serial I/O over controller port
- **Build fix:** None needed; byte-identical out of the box
- **Pass 3 symbols (2026-10-19):** **18 single-name operands** substituted from `locals.inc` via `_tools/apply_symbols.py` — zero residue. Rebuild stays byte-identical.
- **Details:** `Tennis (JU)/README.md`

### 9. Pac-Man (USA) (Namco)
- **Folder:** `NROM/Pac-Man (USA) (Namco)/`
- **ROM:** `rom.nes` (24,592 bytes)
- **Source:** `prg.s` (9,268 lines)
- **Linker:** PRG at $C000, 16 KB; single segment
- **Vectors:** NMI → $C10E (`NmiHandler`), RESET → $C033 (`Reset`; `locals.inc` defines `ResetOffset = $C033`), IRQ → $C17E (`IrqHandler`)
- **Key subsystems:** NMI-synchronized main loop (`MainLoop` at $C04F), game state machine via `MainStateHandlerTable` ($C101, 12 states), game mode state machine via `GameModeStateTable` ($CAD7, 8 states), object/sprite system with fixed-point physics, audio engine ($F8DE) with serial I/O over controller port
- **Build fix:** None needed; byte-identical out of the box
- **Pass 3 symbols (2026-10-19):** **524 single-name operands** substituted from `locals.inc` via `_tools/apply_symbols.py` — **727 multi-alias residues** left numeric (addresses with 2+ aliases, e.g. `$00` = `workPtr0`/`Zp00`). Rebuild stays byte-identical.
- **Details:** `Pac-Man (USA) (Namco)/README.md`

### 10. Donkey Kong 3 (JUE)
- **Folder:** `NROM/Donkey Kong 3 (JUE)/`
- **ROM:** `Donkey Kong 3 (JUE).nes` (24,592 bytes)
- **Source:** `prg.s` (9,952 lines)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C08D (`NmiHandler`; the `prg.s` header block records it as "Pass 2 control-flow entry at CPU $C08D"), RESET → $C000 (`Reset`), IRQ → $C000 (`Reset` reused)
- **Key subsystems:** Main loop with object/game state management at $C02E–$C18D, object movement and geometry calculations ($C28E–$C683), audio engine ($F8DE+) with sound channels ($F0–$FF), PPU command buffer streaming ($C3F4+)
- **Build fix:** Build split `main.s` into `header.s`, `prg.s`, `chr.s`; added `RandomStateAlt = $E4` for `dec $E4` at CPU $E71B (zero-page reuse with `RandomState0 = $54`). **2026-10-16 — one-byte branch-target bug fixed:** the project was recorded as BYTE-IDENTICAL but had never built byte-identical. The `bne` at CPU $C14C (PRG $014C) was annotated `D0 12` (target $C160) but assembled as `D0 0D`, because it was labelled `StoreSelectedPlayerAndScreenFlags` ($C15B) instead of the routine actually at $C160. Retargeted to `ClearAudioSetGameMode` — which is also the semantically correct target for a "mode != $01" test. `cmp` now passes.
- **Details:** `Donkey Kong 3 (JUE)/README.md`

### 11. Donkey Kong Jr. (JU)
- **Folder:** `NROM/Donkey Kong Jr. (JU)/`
- **ROM:** `Donkey Kong Jr. (JU).nes` (24,592 bytes)
- **Source:** `prg.s` (12,807 lines; 6,135 instructions, 266 routines, 68 data labels, 0 conflicts)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C6E6 (`NmiHandler`), RESET → $C66E (`ResetHandler`), IRQ → $FFF0 (stray byte, effectively unused)
- **Key subsystems:** Reset idles in a PRNG-advance loop — the entire frame state machine (title/attract/gameplay/sound) runs inside the NMI handler; VRAM/event queue at $0300 with dispatch table at $BFFE; 8-byte PRNG at $18–$1F; sound timers at $F1AF
- **Build fix:** None needed; byte-identical out of the box (`make` in the project folder). **Pass 1 verified complete 2026-10-16** — a full byte-accounting audit of `prg.s` confirms all 16,384 PRG bytes are emitted exactly once (6,199 instructions + 3,889 `.byte` + 16 `.word`), every emitted value equals the ROM byte, and there are zero audit-comment mismatches or duplicate addresses. No `.incbin` remains. A complete-opcode static tracer independently reaches 6,135 instructions / 12,358 code bytes (75.4%) — every one of which is already present in the file, and the file carries 121 further code bytes the tracer does not find (reached via the `DeferredTaskHandlerTable` dispatch at $BFFE). Pass 2/3 naming is complete; Pass 3 tables are named (`DeferredTaskHandlerTable`, `HudDigitDescriptorTable`, …)
- **Details:** `Donkey Kong Jr. (JU)/README.md`

### 12. CIRCUS
- **Folder:** `NROM/CIRCUS/`
- **ROM:** `rom.nes` (24,592 bytes)
- **Source:** `prg.s` (~12,755 lines)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C05A (`NmiHandler`), RESET → $C000 (`Reset`), IRQ → $4CB7 (outside mapped space — effectively unused)
- **Key subsystems:** NMI-driven frame state machine — main loop is a spin loop at $C057, all per-frame work runs in NMI; main state dispatcher at $C0D0 with 16-state pointer table; controller input with edge flags at $09; menu system with text table at $C763 ("CONTINUE", "STAGE", "SELECT", "PLAY"); palette/screen transfer via descriptor streams; VRAM queue processing; variant object state machine at $DC3F–$FE7B; audio engine with sequence data at $FABB–$FFFB
- **Build fix:** None needed; byte-identical out of the box (`make` in the project folder). Pass 1/2/3 complete — full code/data classification, semantic routine naming, and data table naming all done
- **Pass 3 symbols (2026-10-19):** **118 operands substituted** (38 single-name + 80 hardware) from `symbols.inc`/`locals.inc` via `_tools/apply_symbols.py` — **23 multi-alias residues** left numeric (addresses with 2 aliases: `$E4`=`Controller1Shift`/`ZpE4`, `$7C`=`WorkPointer0Lo`/`Zp7C`, `$7E`=`WorkPointer1Lo`/`Zp7E`). Rebuild stays byte-identical.
- **Details:** `CIRCUS/README.md`

### 13. Wild Gunman (U)
- **Folder:** `NROM/Wild Gunman (U)/`
- **ROM:** `rom.nes` (24,592 bytes)
- **Source:** `prg.s` (~3,000 lines with routine headers)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C086 (`NmiHandler`), RESET → $C000 (`Reset`), IRQ → $C000 (reuses `Reset`)
- **Key subsystems:** NMI-driven frame loop — main loop is a spin loop waiting on NMI phase flag ($20); NMI handler does OAM DMA ($4014), PPU updates, and calls game logic subroutines ($C29F, $C233, $C3AC, $C265); main state dispatcher at $C0B3 based on `GameMode` ($30); reset copies sprite/OAM data from $C844 to $05F0; APU enabled via $4015 = $0F
- **Build fix:** None needed; byte-identical out of the box (`make` compares the whole ROM in the project folder: `cmp reconstructed.nes rom.nes`). **Pass 1 redone 2026-10-16** — the original tracer followed only RESET/NMI/IRQ and jsr/jmp/branch targets and knew just the 151 documented opcodes, so it missed Wild Gunman's runtime dispatch (`Label_C341`'s `pla`-based computed goto puts the jump table inline right after each `jsr $C341`) and filed ~4.9 KB of real code as `.byte` data. Code coverage went **1,597 instr / 3,352 B (20.5%) → 3,956 instr / 8,085 B (49.3%)**. **Pass 2 complete** — all 733 labels carry names (zero `Label_Cxxxx`/`SubCxxxx` remain), routine headers on every entry point, zero-page aliases in `locals.inc` (`GameMode`=$30, `NmiPhase`=$20, `NmiFlag`=$22, `Timer2F`=$2F, etc.). **Pass 3 complete** — data tables named: `SpriteAttributeTable` ($C6AC), `NoteVolumeTable` ($F3EF), `VolumeEnvelopeTable` ($F48F), `SpritePositionTable` ($F77C); the OAM sprite block at $C844 is documented in-place as a comment rather than a label
- **Pass 3 symbols (2026-10-19):** **76 operands substituted** (11 single-name + 65 hardware) from `symbols.inc`/`locals.inc` via `_tools/apply_symbols.py` — zero residue. Rebuild stays byte-identical.
- **Details:** `Wild Gunman (U)/README.md`

### 14. Joypad Test Cartridge (U)
- **Folder:** `NROM/Joypad Test Cartridge (U)/`
- **ROM:** `rom.nes` (24,592 bytes)
- **Source:** `prg.s` (4,401 lines; 202 routines, all with described headers)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $CCF7 (`NmiHandler`), RESET → $C000 (`Reset`), IRQ → $C000 (reuses `Reset`)
- **Key subsystems:** NMI-driven frame loop — main loop spins waiting on NMI phase; NMI handler does OAM DMA ($4014), PPU scroll/control latch, and burst VRAM writes from table at $0302; `VramPtrWrite` ($CD3F) uses a return-address modification trick at `RetAddrUpdate` ($CDC8) for runtime-computed dispatch; `VramWrite` ($CDEE) sets PPU address and writes data to PPUDATA; reset clears RAM, initializes PPU ($2000=$10, $2001=$00), triggers OAM DMA, and enters main loop
- **Build fix:** Byte-identical out of the box, but **Pass 1 was badly truncated and has been redone**. It claimed 282 instructions / 580 bytes (3.5%); the tracer halted at `$C09E` on `DCP $3C20` (`$CF`), an undocumented opcode used as ordinary code, and filed 3,256 bytes of real code as `.byte`. Now **1,773 instructions / 3,836 bytes (23.4%)**, verified against a fresh trace. `nesdis.py --undocumented` supplies the 105 undocumented NMOS opcodes; ca65 V2.19 encodes none of them, so the 4 affected instructions are emitted as explicit `.byte` with the disassembly in the comment. Pass 2 then renamed all 202 labels (zero `Label_Cxxxx` left) and rewrote all 202 routine headersr all labels, semantic naming for key routines, zero-page aliases in `locals.inc` (`VramPtrLo`=$00, `PpuCtrlShadow`=$EF, `FrameCounterLo`=$53, etc.)
- **Pass 3 symbols (2026-10-19):** **47 hardware operands** substituted from `symbols.inc` via `_tools/apply_symbols.py` — zero residue. Rebuild stays byte-identical.
- **Details:** `Joypad Test Cartridge (U)/README.md`

### 15. NES PowerPad Test Card (U)
- **Folder:** `NROM/NES PowerPad Test Card (U)/`
- **ROM:** `rom.nes` (24,592 bytes)
- **Source:** `prg.s` (8,842 lines)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $E06E (`NmiHandler`), RESET → $E000 (`Reset`), IRQ → $E000 (reuses `Reset`)
- **Key subsystems:** Minimal NMI-driven test cartridge — NMI reads PowerPad via $4016, processes transitions, updates score/lives display; APU at $4015=$0F; 7.2% code coverage
- **Build fix:** None needed; byte-identical out of the box
- **Pass 3 symbols (2026-10-19):** **89 hardware operands** substituted from `symbols.inc` via `_tools/apply_symbols.py` — zero residue. Rebuild stays byte-identical.
- **Details:** `NES PowerPad Test Card (U)/README.md`

### 16. MUSCLE (U)
- **Folder:** `NROM/MUSCLE (U)/`
- **ROM:** `M.U.S.C.L.E. (U).nes` (24,592 bytes); `rom.nes` is a relative symlink `../M.U.S.C.L.E. (U).nes`
- **Source:** `prg.s` (Pass 1/2/3 output, with 42 bytecode listings above the `.byte` data)
- **Linker:** HEADER at $0000 (16 bytes), **PRG at $8000 (16 KB)**, CHR at $0000 (8 KB) — the one ROM in the set mapped *low*
- **Vectors:** NMI → $86CB (`NmiHandler`), RESET → $8000 (`Reset`), IRQ → $8764 (a bare `RTI` that doubles as the NMI epilogue). Vectors themselves sit in the $C000 mirror at $FFFA.
- **Key subsystems:** bytecode VM — 40 opcodes at `$C8-$EF` handled through a table at `$9237`, everything else a literal operand. Gameplay dispatches through three jump tables plus two zero-page `jmp (zp)` calls a static descender cannot follow: 38-entry token-program pointer table at `$8CEF`, 40-entry opcode handler table at `$9237`, 16-entry handler table at `$9F2B`, 3-entry per-level VRAM-writer table at `$AC35`. Compressed-VRAM RLE decoder at `$AC82` with a 12-byte fill table at `$ACBD`; division by 20 restored at `$82AC`; four-channel sound engine with per-channel state in zero page `$C4-$EF`.
- **Build fix:** the skeleton's `$C000` linker assumption was wrong — RESET is `$8000`, so `linker.cfg` had to move. `Makefile` tool paths were `../../../_tools/` while in `_wip/`; promotion to top-level required `../../_tools/`. `make regen` (pass1→pass2→pass3) reproduces `prg.s` byte-for-byte.
- **Pass 3 symbols (2026-10-19):** **220 operands substituted** (91 single-name + 129 hardware) from `symbols.inc`/`locals.inc` via `_tools/apply_symbols.py` — zero residue. Rebuild stays byte-identical.
- **Details:** `MUSCLE (U)/README.md`

### 17. Lunar Pool (U)
- **Folder:** `NROM/Lunar Pool (U)/` (promoted out of `_wip/` 2026-10-18 by `git mv`, so the relative `rom.nes` symlink is live and tool paths are `../../_tools/`)
- **ROM:** `Lunar Pool (U).nes` (24,592 bytes)
- **Source:** `prg.s` (5,300 instructions, 67.6% code / 11,077 bytes; 705 labels, zero `Label_` residue, 38 semantic zero-page aliases + 66 neutral, 33 named data tables)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $FF65 (`NmiHandler`), RESET → $E80C (non-$C000 entry), IRQ → $FF64 (bare `rti`, adjacent to NMI)
- **Key subsystems:** NMI-driven frame loop with PPU command queue and VRAM transfers; main loop at $E80C; side-scrolling / pool gameplay; audio engine; print-inline-string helper at $CBDC/$CBC9
- **Build fix:** Promotion from `_wip/` added `header.s`, `chr.s`, HEADER/PRG/CHR `linker.cfg`, and whole-ROM `cmp`; rebuilt from Mesen CDL capture (10,028 bytes Code). **Pass 1/2/3 complete** — byte-identical at whole-ROM level.
- **Pass 3 symbols (2026-10-19):** **45 operands substituted** (18 single-name + 27 hardware) from `symbols.inc`/`locals.inc` via `_tools/apply_symbols.py` — zero residue. Rebuild stays byte-identical.
- **Details:** `Lunar Pool (U)/README.md`

### 18. Donkey Kong (JU)
- **Folder:** `NROM/Donkey Kong (JU)/` (promoted out of `_wip/` 2026-10-19 by `git mv`, so the relative `rom.nes → ../Donkey Kong (JU).nes` symlink survived)
- **ROM:** `Donkey Kong (JU).nes` (24,592 bytes)
- **Source:** `prg.s` (6,014 instructions, 76.3% code / 12,505 bytes; 1,015 labels with **zero `Label_` residue**, 145 zero-page slots with neutral `ZpXX` names, 10 named data regions)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C85F (`NmiHandler`), RESET → $C79E (non-$C000 entry, like DK Jr.), IRQ → $FFF0 (vector-page padding, unused)
- **Key subsystems:** reset enters at $C79E; NMI-driven frame loop; dispatchers at $C807/$C815/$C823/$C831/$C847 load 16-bit pointers from `ObjectPtrTable` ($C03C) and from `$C4A7,x`; large level-data pointer block $C044–$C79D; sound engine over `MusicDataTable` ($F55B), `APUDataTable` ($FAE6), `SfxDataTable` ($FE59)
- **Pass 2 (2026-10-19):** all 919 `Label_XXXX` definitions named — 102 new semantic routine names + 217 `SubC<addr>` entry names (honest residue) + 600 derived `<Routine>_Block[_n]` internal branch targets; `jsr`/`jmp` operands stay numeric (`Wild Gunman (U)` style). Applied with `_tools/pass2.py apply`; `make` still byte-identical
- **Build fix:** none at PRG level — it was PRG-identical in `_wip/` and stayed byte-identical through Pass 3. Promotion added `header.s`, `chr.s`, a HEADER/PRG/CHR `linker.cfg`, the `rom.nes` symlink, and the whole-ROM `cmp`; no `_tools` path change (the Makefile never referenced `_tools/`) and no `make regen` target. Mirroring was recorded as Vertical in the project README (then named OVERVIEW) but header byte 6 = $00 says **Horizontal** — corrected at promotion
- **Pass 3 symbols (2026-10-19):** **75 operands substituted** (17 single-name + 58 hardware) from `symbols.inc`/`locals.inc` via `_tools/apply_symbols.py` — zero residue. Rebuild stays byte-identical.
- **Details:** `Donkey Kong (JU)/README.md`

### 31. Pac-Man (Tengen) (U)
- **Folder:** `NROM/Pac-Man (Tengen) (U)/` (promoted out of `_wip/NROM/` 2026-10-20 by `git mv`)
- **ROM:** `Pac-Man (Tengen) (U) [!].nes` (24,592 bytes), reached through the `rom.nes` symlink
- **Source:** `prg.s` (4,595 lines; 1,637 instruction lines covering 3,273 code bytes = 20.0%; 227 labels — 199 routine entries + 28 branch targets — **zero `Label_` residue**, zero raw `$XXXX` jsr/jmp/branch operands, 2,479 canonical audit comments, 0 byte mismatches against `prg.bin`)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C0FA (`NmiHandler`), RESET → **$C033** (`Reset` — the boot sequence is inline here; there is no boot code at $FF00 in this build), IRQ → $C16A (`IrqHandler`)
- **Key subsystems:** NMI frame loop with two controller reads; game-state dispatch through `GameStateDispatchTable` ($C253); maze graphics (`MazeTileGraphics` $C2FD, `AttributeTableData` $C387, `BorderPattern` $C432); ghost AI with the target search at $C8AA and the four-ghost slots; `UpdateMazeTiles` ($DAB0) rewriting the maze through the four overlay tables; score/attribute VRAM writes; the level-script interpreter at $EE8F dispatching through `ScriptCommandTable` ($EFDD)
- **Variant:** a **different build** of the same game as row 32 — 56 PRG bytes differ in 8 runs, all of them code-versus-licensee-text (`$C3E3-$C408` is 26 spaces here against `LICENSED BY NAMCO AMERICA INC` there; `$FF00-$FF16` is `$FF` padding here against the boot code there), and the RESET vector differs to match. The CHR is identical
- **Build fix:** none at PRG level — it was PRG-identical in `_wip/` and stayed byte-identical through Pass 2/3. Promotion added `header.s`, `chr.s`, a HEADER/PRG/CHR `linker.cfg`, the `rom.nes` symlink and the whole-ROM `cmp`; the first promoted build was byte-identical (MD5 `d34e7a74…28ad0`)
- **Pass 2 (2026-10-20):** a fresh map derived from this dump's own committed split — no name, map or file was carried over from the row-32 dump. All 194 `Label_XXXX` definitions renamed to semantic routine entries plus `<Routine>_<Role>` branch targets, and all 48 raw `$XXXX` call operands resolved. Recorded in `routinemap.tsv`
- **Pass 3 (2026-10-20):** 30 semantic zero-page aliases, each applied only at the sites where its role is proven (the per-site choice is in `sites.tsv`; the addresses that carry two roles keep the neutral `ZpXX` name elsewhere, and `locals.inc` records the reason for every remaining neutral slot). 28 data tables named — including `CharacterDataTable` ($C66A) and `CharacterNameStrings` ($C67E), where the ROM itself names Blinky, Pinky, Inky and Clyde. `apply_symbols.py` reports **0 residue**
- **Pass 1 correction (2026-10-20):** six command handlers recovered. `ScriptCommandTable` ($EFDD) is read by the traced instruction at $EFCC, and six of its entries point at $F00A, $F022, $F03A, $F052, $F062 and $F072 — all of which the tracer had left as data, and two of which it had mis-split across the `jmp $EF61` at $F01F and $F04F. Those 120 bytes are code here, decoded straight from the ROM. **The same gap exists in the promoted row-32 dump**, which has not been corrected
- **Residue:** the unreached main game logic at **$C45A–$C55F** is still `.byte` data. It is code — the tracer's own decoder walks it cleanly and the dispatch table at $C511 points into it — but nothing reaches it, so it cannot be entered without a guess. The same gap exists in the row-32 dump. Re-deriving it is a Pass 1 job; a Mesen Code Data Logger capture is the tool the repo uses (`_tools/cdl_reclass.py`)
- **Details:** `Pac-Man (Tengen) (U)/README.md`

### 32. Pac-Man (U)
- **Folder:** `NROM/Pac-Man (U)/` (promoted out of `_wip/NROM/` 2026-10-20 by `git mv`; tool paths stay `../../_tools/`)
- **ROM:** `Pac-Man (U) [!].nes` (24,592 bytes), reached through the `rom.nes` symlink
- **Source:** `prg.s` (4,511 lines; 1,549 audited instruction lines covering 3,058 code bytes, plus 49 `jsr`/`jmp` call sites — 19.6% code by the Pass 1 tracer's accounting; **zero `Label_` residue**, zero raw `$XXXX` call operands)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C0FA (`NmiHandler`), RESET → **$FF00** (`Reset` — real boot code at the vector-page tail, not padding: `sei`/`cld`, PPU off, double vblank wait, `jmp ColdStart` at $C042), IRQ → $C16A (`IrqHandler`)
- **Key subsystems:** NMI-driven frame loop; game-state dispatch through `GameStateDispatchTable` ($C253) via `jmp (DispatchPtrLo)`; entity dispatch through `EntityPtrTable` ($D912) and a second table at $D9B9; palette upload from $0299/$02A9; VRAM write queue at $026B/$0272; audio engine with `AudioCommandTable` ($EFDD) dispatched via `jmp (AudioHandlerPtrLo)`; 15-byte copyright signature `ProgrammerSig` ($C0EB) checked against RAM at $0052
- **Build fix:** none at PRG level — it was PRG-identical in `_wip/` and stayed byte-identical through Pass 2/3. Promotion added `header.s`, `chr.s`, a HEADER/PRG/CHR `linker.cfg`, the `rom.nes` symlink and the whole-ROM `cmp`; the first promoted build was byte-identical (MD5 `a69d310f8cae9397fbd39f204672b5c7`)
- **Pass 2 (2026-10-20):** fresh map derived from the committed split (not from a drafted map): all 194 `Label_XXXX` definitions renamed to semantic routine entries plus `<Routine>_<Role>_<addr>` internal branch targets, and all 49 `jsr`/`jmp` call sites resolved to labels. Recorded in `routinemap.tsv` / `derived_names.tsv`
- **Pass 3 symbols (2026-10-20):** **119 operands substituted** (101 hardware + 11 single-name + 7 multi-alias resolved per site via `sites.tsv`) — `apply_symbols.py` reports **0 residue**. The 7 site resolutions are all proven from context: four `jmp ($0010)` immediately preceded by `sta DispatchPtrLo`/`sta DispatchPtrHi`, one `jmp ($00FE)` preceded by `sta AudioHandlerPtrLo`/`sta AudioHandlerPtrHi`, and two `sta a:$0000,y` zero-page clears that take the neutral `Zp00`. Audit-comment alignment was re-done afterwards with the new `_tools/align_audit_comments.py` (whitespace-only)
- **Details:** `Pac-Man (U)/README.md`

### 29. Hogan's Alley (JU)
- **Folder:** `NROM/Hogan's Alley (JU)/` (promoted out of `_wip/NROM/` 2026-10-20 by `git mv`)
- **ROM:** `Hogan's Alley (JU).nes` (24,592 bytes), reached through the `rom.nes` symlink
- **Source:** `prg.s` (10,920 lines; 3,950 instruction lines covering 8,041 code bytes = 49.1%; 681 labels, **zero `Label_` residue**, zero raw `$XXXX` jsr/jmp/branch operands, 4,490 canonical audit comments, 0 byte mismatches against `prg.bin`)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C088 (`NmiHandler`), RESET → $C000 (`Reset`), IRQ → $C000 (the same address)
- **Key subsystems:** the frame heartbeat — the NMI sets `GameFramePending` ($20) and the main loop spends it, with `NmiPhaseFlag` ($22) stopping the per-frame work from running twice; an **inline** dispatch architecture — `IndirectCall` at $C34D pops the return address of the `jsr` that called it and reads a 16-bit handler pointer from the word that follows, so the six handler tables live *inside* the code stream ($C124 19 entries, $C219 4, $C89C 14, $CDD1 1, $D234 2, $D3D6 14); the Zapper on `$4017` (`ReadZapper` $CF3E) with the controller debounced over five frames into `Player1Buttons` ($16); a three-accumulator sound engine (`SoundFlag0`/`1`/`2` at $F0–$F2) fed by 24 one-bit stubs and read at $F9FF/$FC48/$FAFC, with the note records in `NoteParameterTable` ($FCC8)
- **Build fix:** none at PRG level — it was PRG-identical in `_wip/` and stayed byte-identical through Pass 2/3. Promotion added `header.s`, `chr.s`, a HEADER/PRG/CHR `linker.cfg`, the `rom.nes` symlink and the whole-ROM `cmp`; the first promoted build was byte-identical
- **Pass 1 correction (2026-10-20):** the static trace classified only 41.8 % of the PRG as code. A fresh Mesen Code Data Logger capture was merged with the four captures already in the folder (`hogans_merged.cdl`, the OR of five per-byte flag arrays, 6,544 code bytes) and `_tools/cdl_reclass.py` rewrote the split to match what the CPU actually fetched: **1,216 bytes** moved from data to code, five moved the other way and 59 labels were emitted. The four branch targets the tool could not prove were turned into labels by the new `_tools/resolve_raw_branches.py`
- **Pass 2 (2026-10-20):** a fresh map derived from this dump's own committed split: 206 routine entries hand-named and 413 internal branch targets derived mechanically by `_tools/derive_branch_names.py`, 630 `Label_XXXX` definitions gone, 484 raw `$XXXX` call operands resolved, 15 call targets the tracer had never labelled given a label. Recorded in `routinemap.tsv`
- **Pass 3 (2026-10-20):** 60 semantic zero-page aliases, each applied only where its role is proven (`zp_aliases.inc` and `zp_alias_sites.tsv`); the slots that stay neutral are each listed with the reason. 34 data tables named — `SubStateHandlerTable`, `ModeHandlerTable`, `HandlerDispatchTable`, `ActorCommandTable`, `TargetBehaviourTable`, `NoteParameterTable` and the rest — and recorded in `data_region_names.tsv`. `apply_symbols.py` reports **1 residue**: `sta a:$00B4,y` at $C203, the same address as `Zp40`/`ActorPalette` but forced to absolute addressing, so it must stay numeric
- **Residue:** no `make regen` target. The Pass 1 split here is the static trace *corrected* by a CDL capture, and the base the correction was applied to is not what the current `_tools/nesdis.py` produces, so a regen pipeline could not reproduce `prg.s` byte for byte. `prg.s` is the maintained source of truth
- **Details:** `Hogan's Alley (JU)/README.md`

### 30. Mario Bros (JU)
- **Folder:** `NROM/Mario Bros (JU)/` (promoted out of `_wip/NROM/` 2026-10-20 by `git mv`)
- **ROM:** `Mario Bros (JU).nes` (24,592 bytes), reached through the `rom.nes` symlink
- **Source:** `prg.s` (16,345 lines; 6,210 instruction lines covering 12,847 code bytes = 78.4%; 1,025 labels, **zero `Label_` residue and zero `SubC` residue**, zero raw `$XXXX` jsr/jmp/branch operands, 6,458 canonical audit comments, 0 byte mismatches against `prg.bin`)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C07D (`NmiHandler`), RESET → $C000 (`Reset`), IRQ → $C000 (the same address)
- **Key subsystems:** the frame heartbeat — the NMI sets `FramePendingFlag` ($20) and the main loop spends it, with `NmiPhaseFlag` ($22) stopping the NMI handler from doing its per-frame work twice; an **inline** dispatch table — the handler pointers sit in the middle of the code stream, right after the call that reads them, so the static tracer cannot follow them (`GameStateHandlerTable` $C510 and its five continuation blocks); a script interpreter that drives the enemies (`SetupScriptPointer` $CB85, `FetchScriptByte` $E9FA, `RunScript` $E9D3) with the command byte compared against $AA and $BB; the Zapper-free controller read with a five-frame debounce into `Zp10`/`Zp11`; a per-note sound engine at $F8A7–$FD27 working from the note table at $FCC8
- **Build fix:** none at PRG level — it was PRG-identical in `_wip/` and stayed byte-identical through Pass 2/3. Promotion added `header.s`, `chr.s`, a HEADER/PRG/CHR `linker.cfg`, the `rom.nes` symlink and the whole-ROM `cmp`; the first promoted build was byte-identical
- **Pass 1 correction (2026-10-20):** the committed split was a strict subset of the correct one — only 72.0% of the PRG was classified as code. A Mesen Code Data Logger capture of this ROM (`mario_mesen.cdl`, 10,915 code bytes) showed **1,010 bytes** the tracer had left as data were code; the two branch targets the capture never reached (`$E4CB` and `$E639`) were forced with `--override` and account for 57 more, so **1,067 bytes** moved from data to code and 22 moved the other way. The biggest single win is `$D508`–`$D56D`, a hundred bytes that decode as a coherent routine, and `$CA3B`–`$CA5D`, the tile-drawing routine. The three branch targets the reclassifier could not prove were turned into labels by `_tools/resolve_raw_branches.py`
- **Pass 2 (2026-10-20):** a fresh map derived from this dump's own committed split: 206 routine entries and 519 internal branch targets, 931 `Label_XXXX` definitions gone, 51 raw `$XXXX` call operands resolved and 12 call targets the tracer had never labelled given a label. **Zero `SubC` residue**: the 185 entries the previous session had left as address-derived residue were all named from the code. Recorded in `routinemap.tsv`
- **Pass 3 (2026-10-20):** 25 semantic zero-page aliases, each applied only where its role is proven (`zp_aliases.inc`); the slots that stay neutral are each listed with the reason. 35 data tables named — `GameStateHandlerTable`, `EnemyBehaviourTable`, `EnemyScriptTable`, `EnemyTypePointerTable`, `SoundRoutineTable`, `NoteFrequencyTable` and the rest — and recorded in `data_region_names.tsv`. `apply_symbols.py` reports **0 residue**
- **Details:** `Mario Bros (JU)/README.md`

### 33. Pyramid (U) (Sachen)
- **Folder:** `NROM/Pyramid (U)/` (promoted out of `_wip/NROM/` 2026-10-20 by `git mv`)
- **ROM:** `Pyramid (U) (Sachen).nes` (24,592 bytes), reached through the `rom.nes` symlink
- **Source:** `prg.s` (8,253 lines; 3,130 instruction lines covering 6,493 code bytes = 39.6%; 463 labels, **zero `Label_` residue**, zero raw `$XXXX` jsr/jmp/branch operands, 3,762 canonical audit comments, 0 byte mismatches against `prg.bin`)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $D72E (`NmiHandler`), RESET → $FF00 (`Reset`), IRQ → $FF00 (the same address — `sei` is never undone, so the IRQ never fires)
- **Key subsystems:** the unlicensed Sachen boot (`sta $4100` mapper unlock with a delay loop at $FF4C, the "A"/"V" check on RAM $0120/$0121 at $FF57, the seed at $FF69, the clear at $FF74, the hand-off to the game's own entry at $C800); a task table of `jmp` trampolines that live inside the data regions ($C01E, $C02A, $C042, $C054) plus ten more at $C000–$C01B; two queued-event dispatchers that jump through the zero page with `jmp ($0002)` ($C3A3 with `TaskVectorTable1` $C3A6, $CCCA with `TaskVectorTable2` $CCD5); a VRAM command list assembled in the $0700 buffer and flushed by `FlushVramCommandList`; the actor grid at $0436 with the actor tables at $D320/$D4EE/$D5D5; a four-voice sound engine with its period, envelope and sample tables
- **Build fix:** none at PRG level — it was PRG-identical in `_wip/` and stayed byte-identical through Pass 2/3. Promotion added `header.s`, `chr.s`, a HEADER/PRG/CHR `linker.cfg`, the `rom.nes` symlink and the whole-ROM `cmp`; the first promoted build was byte-identical (MD5 `aa285ff1…6c59e2`)
- **Pass 1 correction (2026-10-20):** the committed split was a strict subset of the correct one — **828 bytes** of code were still marked as data, because the tracer cannot follow a `jmp` that sits inside a data region. Re-tracing with the sixteen `jmp`-table targets, the `$C800` boot mainline and six further code starts seeded by hand recovers them (plus a five-byte stub at $DF89 in a hole between two routines), and the re-trace loses **no** committed code byte. `make regen` reproduces the split, so it stays verifiable
- **Pass 2 (2026-10-20):** a fresh map derived from this dump's own committed split: 431 routine entries and the 32 data blocks named, 428 `Label_XXXX` definitions gone, 320 raw `$XXXX` call operands resolved. The internal branch-target names are derived mechanically from the branch that reaches them by `_tools/derive_branch_names.py`. Recorded in `routinemap.tsv`
- **Pass 3 (2026-10-20):** 24 semantic zero-page aliases, each applied only where its role is proven (`zp_aliases.inc`); the 57 slots that stay neutral are each listed with the reason. 32 data tables named — `TaskVectorTable1`/`TaskVectorTable2`, `LevelScriptData`, `MusicPeriodTable`, `SoundEnvelopeTable`, the actor tables — and recorded in `data_region_names.tsv`. `apply_symbols.py` reports **0 residue**
- **Residue:** the zero page is reused heavily — 410 references still carry a neutral name, mostly the general-purpose scratch of the shift and arithmetic helpers. 482 absolute operands point at RAM and stay numeric. `sta $4100` stays a raw operand: it is outside the `$2000-$4017` range `PROMPTS.md` asks to be symbolic, and no hardware name would describe a mapper unlock
- **Details:** `Pyramid (U)/README.md`


### 34. Raid on Bungeling Bay (U)
- **Folder:** `NROM/Raid on Bungeling Bay (U)/` (promoted out of `_wip/NROM/` 2026-10-20 by `git mv`)
- **ROM:** `Raid on Bungeling Bay (U).nes` (24,592 bytes), reached through the `rom.nes` symlink
- **Source:** `prg.s` (~14,300 lines; 255 `SubC<addr>` entry points, 612 `Sub_<Role>_<addr>` branch names, **zero `Label_` residue**, zero raw `$XXXX` jsr/jmp/branch operands)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C04C (`NmiHandler`), RESET → $C000 (`Reset` → `ResetEntry` at $C6E3), IRQ → $C2C0 (`IrqHandler`)
- **Key subsystems:** NMI frame loop with two paths (`NmiPathSelector` $C4: minimal vs full); state bitmap at $0200 dispatching on bits 0–3; PPU helper at $C006; sprite/OAM update at $C08E; palette update at $C4E4; main game logic at $C17A; PRNG at $C412; four computed indirect jumps at $E2EC / $E79D / $E7A0 / $E7A3
- **Build fix:** none at PRG level — it was PRG-identical in `_wip/` and stayed byte-identical through Pass 2/3. Promotion added `header.s`, `chr.s`, a HEADER/PRG/CHR `linker.cfg`, the `rom.nes` symlink and the whole-ROM `cmp`; the first promoted build was byte-identical (MD5 `77285503…885000ac`)
- **Pass 3 (2026-10-20):** 11 semantic zero-page aliases added to `locals.inc` and applied at the proven sites. One of them was **corrected** while the `[a2]` sibling was finished: `$EA` had been named `VBlankWaitCounter`, but the routine at `$C412` is the game's PRNG (the classic `eor`/`asl`/`php`/`lsr`/`plp`/`rol` scrambler, called thirteen times from gameplay code, twice in a row at `$CDF4`/`$CDF9` with the second result masked `#$07`), so `$EA` is the scrambler's phase counter. Renamed `PrngPeriodCounter`, and `$EB`/`$EC` were named `PrngSeedB`/`PrngState`. Two `sta a:IndDispatch17,y` operands that were absolute stores to RAM `$0017` were also corrected to `a:Zp17,y`
- **Details:** `Raid on Bungeling Bay (U)/README.md`

### 35. Raid on Bungeling Bay (U) [a2]
- **Folder:** `NROM/Raid on Bungeling Bay (U) [a2]/` (promoted out of `_wip/NROM/` 2026-10-20 by `git mv`)
- **ROM:** `Raid on Bungeling Bay (U) [a2].nes` (24,592 bytes), reached through the `rom.nes` symlink
- **Source:** `prg.s` (14,326 lines; 5,079 instruction lines covering 10,536 code bytes = 64.3%; 866 labels — 252 `SubC<addr>` entries + 610 `Sub_<Role>_<addr>` branch names — **zero `Label_` residue**, zero raw `$XXXX` jsr/jmp/branch operands, 5,467 canonical audit comments, 0 byte mismatches against `prg.bin`)
- **Linker:** HEADER at $0000 (16 bytes), PRG at $C000 (16 KB), CHR at $0000 (8 KB)
- **Vectors:** NMI → $C04C (`NmiHandler`), RESET → $C000 (`Reset` → `ResetEntry` at $C6E3), IRQ → $C2C0 (`IrqHandler`)
- **Key subsystems:** same structure as row 34 — NMI frame loop with two paths, state bitmap at $0200, PPU helper at $C006, sprite/OAM update at $C08E, palette update at $C4E4, main game logic at $C17A, PRNG at $C412, four computed indirect jumps
- **Variant:** a **different build** of the same game as row 34 — 150 of the 16,384 PRG bytes differ, in 7 runs, all of them code-versus-copyright-text at `$C67D–$C6D8` and `$C73B–$C779`; the CHR differs too; header byte 6 is $00 (Horizontal) against row 34's $01 (Vertical). The zero-page reference sets are otherwise identical
- **Build fix:** none at PRG level — it was PRG-identical in `_wip/` and stayed byte-identical through Pass 2/3. Promotion added `header.s`, `chr.s`, a HEADER/PRG/CHR `linker.cfg`, the `rom.nes` symlink and the whole-ROM `cmp`; the first promoted build was byte-identical (MD5 `659d340a1e9d420eee28df13319b0094`)
- **Pass 3 (2026-10-20):** 15 semantic zero-page aliases added to `locals.inc` and applied at the proven sites — every alias is applied only where its role is proven, and the addresses that carry two names keep the neutral name at the sites where the other role applies (`$01` is `PtrHi` at the 16-bit compare and `IndDispatch01` at the dispatch; `$17` is `IndDispatch17` at the dispatch and `Zp17` for the absolute RAM `$0017` store in the copy loop). The new `_tools/apply_zp_aliases.py` does the per-site substitution, because `apply_symbols.py` only rewrites numeric operands
- **Details:** `Raid on Bungeling Bay (U) [a2]/README.md`

### 36. Urban Champion (JU)
- **Folder:** `NROM/Urban Champion (JU)/`
- **ROM:** `Urban Champion (JU).nes` (24,592 bytes)
- **Source:** `prg.s` (~4,000 lines)
- **Linker:** PRG at $C000, 16 KB; single segment
- **Vectors:** NMI → $CA91 (`NmiHandler`), RESET → $CA00 (`Reset`), IRQ → $CA00 (reuses `Reset`)
- **Key subsystems:** NMI-driven frame loop with simple fight game logic; minimal code (33.9%)
- **Build fix:** None needed; byte-identical out of the box
- **Pass 3 symbols (2026-10-19):** **70 operands substituted** (4 single-name + 66 hardware) from `symbols.inc`/`locals.inc` via `_tools/apply_symbols.py` — zero residue. Rebuild stays byte-identical.
- **Details:** `Urban Champion (JU)/README.md`

---

## `_wip/` Projects

The pre-promotion tier is documented in **`WIP.md`**. It now holds **857
projects** across **30 mapper folders**:

| Folder | Mapper | Projects |
|--------|--------|----------|
| `_wip/NROM/` | 0 | 38 |
| `_wip/MMC1/` | 1 | 221 |
| `_wip/UNROM/` | 2 | 98 |
| `_wip/CNROM/` | 3 | 58 |
| `_wip/MMC3/` | 4 | 239 |
| `_wip/MMC5/` | 5 | 10 |
| `_wip/MAPPER7/` … `_wip/MAPPER232/` | 7-232 | 193 |

All 857 build **byte-identical for the whole ROM** — the tier was moved off
the old PRG-level-only compare on 2026-10-20, so the header and CHR are now
proven for every project here, exactly as in the promoted tier. **856 of them
are Pass 0 skeletons**: the folder shape and the build are proven, but
`prg.s` is still a single `.incbin "prg.bin"`. Only `Golf (JU)` carries a
real disassembly (Pass 1 + Pass 2).

Two things are worth knowing before touching a `_wip/` project:

- **Most of the tier is a banked mapper with a PRG image larger than the
  6502's address space.** Only two projects have a 16 KB PRG; 151 have
  32 KB, 523 have 128 KB and one (`Action 52 (U) [!]`) has 1.5 MB. Those
  projects link their MEMORY areas at *file offsets* rather than CPU
  addresses, which is both the only option and the honest model. See
  "Two linker layouts" in `WIP.md`.
- **227 projects have no CHR at all** — the mapper supplies CHR RAM.

The tier is deliberately **not** built by the root `Makefile` — `MAPPERS`
names only the promoted mapper folders. Build it explicitly:

```
for d in _wip/*/*/; do make -C "$d"; done
```

Promotion is now just `git mv` plus the disassembly work: the whole-ROM
build, the `header.s`/`chr.s` sources, the HEADER/PRG/CHR `linker.cfg` and
the `rom.nes` copy are already in place. No `_tools` path change is needed,
because both tiers sit two levels deep, so `../../_tools/` is correct either
way. `Lunar Pool (U)`, `Donkey Kong (JU)`, `Popeye (JU) (PRG 1)`,
`Raid on Bungeling Bay (U)`, `Pac-Man (U)`, `Raid on Bungeling Bay (U) [a2]`,
`Pac-Man (Tengen) (U)`, `Pyramid (U)`, `Hogan's Alley (JU)` and
`Mario Bros (JU)` (all 2026-10-20) went through exactly that and came out
whole-ROM byte-identical on the first promoted build.

Notable vector/header observations for Pass 1 work:
- **Pac-Man (U)** RESET at `$FF00` — the vector-page tail, but **not** padding: `$FF00` holds real boot code (`sei`/`cld`, PPU off, double vblank wait, `jmp ColdStart` at `$C042`). The **Tengen variant** RESETs at `$C033` and has no boot code at `$FF00` at all (that region is `$FF` padding) — the same boot sequence is inline at `$C033`. The two PRGs differ in 56 bytes in 8 runs, all of them code-versus-licensee-text.
- **Lunar Pool (U)** NMI `$FF65` / IRQ `$FF64` are adjacent in the vector page; RESET `$E80C`.
- **NES PowerPad Test Card (U)** — *at Pass 2/3*: minimal code (~7.2%), data-heavy test cartridge. RESET at $E000 (non-$C000 entry). NMI handler reads controllers via shift register, processes pad transitions, draws score/lives. See `NES PowerPad Test Card (U)/README.md`.
- **Lunar Pool (U)** — *Pass 2 and Pass 3 complete; promoted to the top level 2026-10-18*: RESET at `$E80C` (not `$C000`), NMI `$FF65`, IRQ `$FF64` (a bare `rti` just before the NMI handler, so IRQs are ignored). There is **no** `jmp ($7961)` RAM-pointer gate (an earlier claim): those three sites fell out of decoding two bytes into the word "player". `$CBDC`/`$CBC9` is a print-inline-string-and-return-after-it helper, so a `jsr $CBDC` is always followed by a `$81`-prefixed, `$00`-terminated string ("player", "shot", "game over", "hi`score__", "perfect_"). The split was re-derived from a Mesen CDL capture (10,028 bytes Code): now **5,300 instructions / 11,077 bytes (67.6%)**, 5,301 data bytes and the six vector bytes as `.word`. Pass 2 named all **705** labels — `Label_<addr>` is gone from the file — and Pass 3 named 33 tables plus the zero-page aliases (38 semantic, 66 neutral, ten former phantom aliases deleted). Residue, recorded rather than guessed: 73 bytes of *reachable* code are still `.byte` (`$EA9A`, `$EADC`, `$EAE5`, `$EAED`, `$EB04`, `$EB16-$EB4F` — the CDL capture never fetched them), another 75 bytes of ending-screen code sit at `$F5F9-$F643`, and ~206 bytes of unreached-but-clearly-code stubs stay data. The full 24,592-byte ROM (header + PRG + CHR) rebuilds byte-identically. See `Lunar Pool (U)/README.md`.
- **Ice Climber (JE) vs (U)**: byte-identical PRG *and* header — only the CHR differs (~regional title graphic).
- **Popeye (JU) PRG 0 vs PRG 1**: different PRG binaries (and mirroring); same vectors.
- **Raid on Bungeling Bay (U) vs [a2]**: `[a2]` differs in mirroring only per header, but PRGs differ — separate builds.
- **Pyramid (U)** (Sachen) — *promoted 2026-10-20*: the unlicensed Sachen boot pokes a mapper unlock at `$4100`, checks the RAM bytes `$0120`/`$0121` against "A"/"V", and dispatches through two queued-event tables with `jmp ($0002)`. It also dispatches through `jmp` trampoline tables that live *inside* the data regions — 828 bytes of code that the tracer could not reach were recovered by hand. See `NROM/Pyramid (U)/README.md`.
- **CIRCUS** — *at Pass 2/3*: full recursive disassembly complete. NMI-driven frame state machine (main loop is a spin loop at $C057). Menu text at $C763 ("CONTINUE", "STAGE", "SELECT", "PLAY"). Object state machine at $DC3F–$FE7B. Audio sequence data at $FABB–$FFFB. See `CIRCUS/README.md`.
- **Joypad Test Cartridge (U)** — *Pass 3 complete*: minimal code (23.4%), data-heavy test cartridge. Data region `$CF06–$FFFF` broken into 20 named sub-blocks; VRAM command stream opcode set decoded via `RetAddrUpdate` return-address modification trick at `$CDC8`. See `Joypad Test Cartridge (U)/README.md`.
- **Wild Gunman (U)** — *Pass 1 redone, Pass 2/3 complete*: NMI-driven frame loop. Gates its code behind runtime computed-goto tables — see the `prg.s` header block and its `README.md`.
- **Mario Bros (JU)** — *Pass 1 corrected, Pass 2/3 complete, promoted 2026-10-20*: the engine's handler tables sit **inline**, right after the `jsr` that reads them, so the static tracer could not follow them. A Mesen Code Data Logger capture showed 1,067 bytes the tracer had left as data were code, taking the split from 72.0% to 78.4%. Pass 2 named every label (zero `Label_`, zero `SubC`) and Pass 3 added 25 semantic zero-page aliases and named 35 data tables. Code is gated behind stack-based indirect dispatch at `$CD9E` and a 20-entry `JSR` thunk table at `$C5A3`. Audio routines in `$F8xx-$F9xx` clearly identifiable from APU register writes. See `NROM/Mario Bros (JU)/README.md`.

## Common Patterns Across All Projects

### Memory Map
Every project uses a single 16 KB PRG bank mapped at CPU **$C000–$FFFF**, with 8 KB CHR. All builds are NROM (no bank switching).

### Interrupt Structure
All projects follow the same NES interrupt pattern:
- **NMI** fires once per frame and is the real-time heartbeat — handles OAM DMA, PPU updates, controller reading, and audio.
- **RESET** performs cold-start hardware init, RAM clearing, and enters the main loop.
- **IRQ** is almost always unused (either `rti` or a self-loop).

Two exceptions worth noting from branches of this family:
- **Excitebike** uses a state-dispatch table at $C000 rather than a conventional inline main loop, and its IRQ vector points into a data region (unused).
- **Donkey Kong Jr.** is the extreme case: its reset path idles forever in a PRNG-advance loop, and the *entire* frame state machine (title, attract, gameplay, sound) executes inside the NMI handler itself. Its reset entry is also at $C66E rather than $C000.

### Build Toolchain
All projects use the same toolchain:
- **ca65** (6502 assembler)
- **ld65** (linker with `.cfg` memory map)
- All rebuilds are verified **byte-identical** to the original `prg.bin` / ROM PRG bank.

### Disassembly Style
All sources are "Pass-1" style disassemblies:
- Every instruction annotated with PRG offset, CPU address, and emitted bytes
- Inline `.byte`/`.word`/`.res` data blocks interleaved with code
- Address-based labels where semantics are not yet resolved: `Label_Cxxxx` (unrenamed internal targets), `SubC<addr>` / `Sub_Cxxxx` (unnamed entry points), `<Routine>_Block[_n]` (internal blocks under a named parent routine)
- Zero-page symbol files (`locals.inc`) and hardware symbol files (`symbols.inc`)

---

## Navigation

Each project is a flat folder under its mapper directory — e.g.
`NROM/Balloon Fight (JU)/` — containing:
- `prg.s` — disassembly source; `header.s`, `chr.s` and the raw `header.bin` / `chr.bin` / `prg.bin` splits (where present)
- `symbols.inc`, `locals.inc` — hardware constants and application symbols
- `linker.cfg`, `Makefile` — memory map and build script
- `rom.nes` — space-free copy/symlink of the original ROM used by the compare
- `README.md` — detailed per-project power-on execution flow analysis

To rebuild any one project:
```bash
cd /home/tmerritt/Projects/disasm/NROM/<Project>
make
```

To build and verify every project at once (all mapper directories):
```bash
cd /home/tmerritt/Projects/disasm
make          # all projects, all mappers
make clean    # clean them all
make MMC3     # one mapper tier only
```

The root `Makefile` covers the **promoted** tier only. The pre-promotion tier
under `_wip/` is built explicitly:
```bash
for d in _wip/*/*/; do make -C "$d"; done
```
See `WIP.md` for the `_wip/` tier's layout, its quirks and its open work.

---

## Pass 1 methodology note (2026-10-16)

The original Pass 1 disassembler had two limitations that silently understated
code coverage. Both are worth knowing before trusting a coverage percentage:

1. **Documented opcodes only.** Its table held the 151 documented 6502 opcodes.
   These ROMs also use the 54 undocumented opcodes and the 26 unofficial NOPs
   as 2/3-byte padding; a tracer that halts on them strands the real code behind.
2. **No runtime dispatch.** It followed only vectors and direct `jsr`/`jmp`/branch
   targets. Games here dispatch through computed jumps — `jmp ($0014)`, the
   `pla`-based inline-table gotos in Wild Gunman (`Label_C341`), and task tables
   like Donkey Kong Jr.'s `DeferredTaskHandlerTable` at $BFFE.

Effect measured per project (old tracer → complete-opcode dispatch-aware tracer):

| Project | Old | Complete | Action taken |
|---------|-----|----------|--------------|
| NES PowerPad Test Card (U) | 546 instr | 559 | Pass 1 already sound |
| Joypad Test Cartridge (U) | 282 instr | **1,773** | Pass 1 redone (23.4% code); Pass 2 complete; Pass 3 complete |
| Wild Gunman (U) | 1,600 instr | **4,083** | Pass 1 redone (49.3% code) |
| Balloon Fight (JU) | 5,216 instr | 5,277 | hand-done file was already better |
| Donkey Kong Jr. (JU) | 6,135 instr | 6,135 | file already complete |

**Joypad Test Cartridge (U) was the last project carrying the old, truncated
Pass 1, and has now been redone.** Its recorded "3.5% code" was really 23.4%: the
tracer stopped at `$C09E` on `DCP $3C20` (`$CF`), an undocumented opcode used as
ordinary code, and 3,256 bytes of real code were filed as `.byte` data. Redoing it
also invalidated its Pass 3, which had described `$C09E–$C173` and `$C17F–$CCF6` as
data — both are code. Pass 3 is now the outstanding work.

The fix generalises: `nesdis.py --undocumented` decodes all 105 undocumented NMOS
opcodes. It is **default off** so that projects whose `prg.s` is already
regen-stable keep reproducing byte-for-byte under `make regen`.

`_tools/verify_pass1.py` checks the **top-level projects** — it selects the project
folders under each mapper directory (`NROM/`, `AOROM/`, `CNROM/`, `MMC1/`, `MMC3/`,
`MMC5/`, `UNROM/`) that carry a `Makefile` and a `prg.bin`/`rom.nes`, so `_wip/`
projects are not covered (they are checked by plain `make`, now at the
whole-ROM level).
Current run, 2026-10-20: all 35 `NROM/` projects build, **all canonical**, and
**no truncated or unfaithful Pass 1**. The
last two carryovers are gone — Joypad Test Cartridge, the last project holding an
old truncated Pass 1, was redone, and Excitebike, the last source with uncommented
instructions, was commented.

The comment-spelling report used to claim that **no project follows the canonical
`; CPU:$xxxx PRG:xxxx AA BB` convention**. That was a bug in the checker, not a fact
about the sources: the `canonical` pattern ends with `$` but was compiled without
`re.MULTILINE`, so it could only ever match once — at end of file — and every
project fell through to whichever laxer spelling matched most lines. Fixed with
`re.M`, the true split was 8 canonical / 3 `pipe` / 2 `short` / `rom` / `bytes` /
`colon` / `slash`; the 2026-10-19 standardization (`_tools/audit_comment_tool.py`
over 9 projects, plus hand fixes to CIRCUS and Excitebike) closed it out, so the
checker now reports **all canonical**.

Inside `_wip/`, only `Golf (JU)` has instructions to comment at all — it is
the one project in that tier with a real disassembly, and its comments use
the pre-canonical spelling (`; C007: AD 02 20`). The other 856 are Pass 0
skeletons with no instructions, so the spelling does not apply to them.
Bringing `Golf (JU)` up to canonical is Pass 2 work, not a build problem.

The old claim that "Excitebike and Pac-Man carry no byte comments at all" is stale
on both counts. Pac-Man (USA) (Namco) is complete (4,695/4,695 instructions
commented), and Excitebike's 1,013-line gap was closed on 2026-10-19 — all 5,376
instruction lines now carry a canonical comment.

The earlier-reported re-trace crash on `MUSCLE (U)` / `Donkey Kong Jr. (JU)`
(`ValueError: invalid literal for int() with base 16: ':$0010'`) was a false alarm:
`nesdis.operand_value()` already strips the emitter's `a:` prefix via
`token.removeprefix("a:").lstrip("$")`, so re-tracing all promoted projects is
clean.

### Resolved — audit comments for Excitebike and Pac-Man (2026-10-19)

Both were hand-written sources with semantic labels but no byte-identity audit
trail. Both now carry canonical `; CPU:$xxxx PRG:xxxx AA BB` comments on every
instruction, and `verify_pass1.py` reports all-canonical across the top level, so
this section is closed.

The `ca65 -l` listing route described here was abandoned, for the reason recorded
in `AGENTS.md`: the listing carries no source line numbers, so entries cannot be
keyed back to source lines. The comment tooling went through the tracer instead
(`_tools/audit_comment_tool.py`, tracer as ground truth). The invariant still
holds and is the check to keep: after inserting comments, `make` must still print
`Byte-identical ROM verified.`, and each comment's byte list must match `prg.bin`
at the stated offset — a wrong offset that still assembles is the failure mode.

---

## Summary

Thirty-five projects sit under `NROM/`, and all 35 rebuild **byte-identical**
to their original ROMs (rows 1-27 below plus row 29 `Hogan's Alley (JU)`,
row 30 `Mario Bros (JU)`, row 31 `Pac-Man (Tengen) (U)`, row 32 `Pac-Man (U)`,
row 33 `Pyramid (U)`, rows 34 and 35 `Raid on Bungeling Bay (U)` and
`Raid on Bungeling Bay (U) [a2]` — all promoted 2026-10-20 — and row 36
Urban Champion, which kept its tail number when it was promoted; row 7
`Excitebike (JU)` was fixed on 2026-10-20 — the byte-596 mismatch was two
`$0A`/`$11` PPU-mask-shadow operands, see `NROM/Excitebike (JU)/README.md`).

The pre-promotion tier holds **857 projects** under `_wip/`, and as of
2026-10-20 all 857 verify **byte-identical for the whole ROM** as well. Row 28
(`Golf (JU)`) is the only one listed in the table above, because it is the
only one with a real disassembly; the other 856 are Pass 0 skeletons, and the
whole tier — its layout, its quirks and its open work — is documented in
**`WIP.md`**. Folder
*locations* changed on 2026-10-20 (mapper directories, flat project folders),
but each row's build-status claim in this table is the state at its own
promotion; verify against the tree with `make` if in doubt.

| # | Project | Build Status | Pass 3 |
|---|---------|--------------|--------|
| 1 | Balloon Fight (JU) | BYTE-IDENTICAL | complete; symbols applied 2026-10-19 (16 `$13` operands left numeric) |
| 2 | Baseball (UE) | BYTE-IDENTICAL | complete; symbols applied 2026-10-19 (121 operands) |
| 3 | Bomberman (U) | BYTE-IDENTICAL | complete |
| 4 | Burger Time (U) | BYTE-IDENTICAL | complete |
| 5 | Clu Clu Land (JU) | BYTE-IDENTICAL | complete |
| 6 | Defender 2 (U) | BYTE-IDENTICAL | complete |
| 7 | Excitebike (JU) | BYTE-IDENTICAL | complete (Pass 2/3 complete); byte-596 `$0A`/`$11` mask-shadow fix + audit-trail re-anchor + 58 `jsr/jmp` operands symbolized 2026-10-20 |
| 8 | Tennis (JU) | BYTE-IDENTICAL | complete; symbols applied 2026-10-19 (18 operands) |
| 9 | Pac-Man (USA) (Namco) | BYTE-IDENTICAL | complete; symbols applied 2026-10-19 (524 operands; 727 multi-alias residues) |
| 10 | Donkey Kong 3 (JUE) | BYTE-IDENTICAL | complete |
| 11 | Donkey Kong Jr. (JU) | BYTE-IDENTICAL | complete (Pass 1 verified) |
| 12 | CIRCUS | BYTE-IDENTICAL | complete; symbols applied 2026-10-19 (118 operands; 23 multi-alias residues) |
| 13 | Wild Gunman (U) | BYTE-IDENTICAL | complete (Pass 1 redone); symbols applied 2026-10-19 (76 operands) |
| 14 | Joypad Test Cartridge (U) | BYTE-IDENTICAL | Pass 3 complete; symbols applied 2026-10-19 (47 operands) |
| 15 | NES PowerPad Test Card (U) | BYTE-IDENTICAL | complete; symbols applied 2026-10-19 (89 operands) |
| 16 | MUSCLE (U) | BYTE-IDENTICAL | complete; symbols applied 2026-10-19 (220 operands) |
| 17 | Lunar Pool (U) | BYTE-IDENTICAL | complete (tables named); symbols applied 2026-10-19 (45 operands) |
| 18 | Donkey Kong (JU) | BYTE-IDENTICAL | complete (Pass 2/3, promoted 2026-10-19); symbols applied 2026-10-19 (75 operands) |
| 19 | Donkey Kong Jr. Math (U) | BYTE-IDENTICAL | complete (Pass 3 complete); promoted into `NROM/` 2026-10-20 after fixing the mislabeled `SubCF218` call sites |
| 20 | **Duck Hunt (JUE)** | **BYTE-IDENTICAL** | **complete (Pass 3 complete)** |
| 21 | **Ice Climber (JE)** | **BYTE-IDENTICAL** | **complete (Pass 3 complete)** |
| 22 | **Ice Climber (U)** | **BYTE-IDENTICAL** | **complete (Pass 3 complete)** |
| 23 | **Lode Runner (U)** | **BYTE-IDENTICAL** | **complete (Pass 2/3 complete)** |
| 24 | **Pinball (JU)** | **BYTE-IDENTICAL** | **complete (Pass 2/3 complete)** |
| 25 | **Millipede (U)** | **BYTE-IDENTICAL** | **complete (Pass 2/3 complete, 74.6% code)** |
| 26 | **Popeye (JU) (PRG 0)** | **BYTE-IDENTICAL** | **complete (Pass 2/3 complete, 72.3% code)** |
| 27 | **Popeye (JU) (PRG 1)** | **BYTE-IDENTICAL** | **complete (Pass 2/3 complete, 72.3% code); promoted 2026-10-20** |
| 31 | **Pac-Man (Tengen) (U)** | **BYTE-IDENTICAL** | **partial (Pass 2 complete, Pass 3 partial — 30 zero-page aliases, 28 named data tables, 0 residue, 20.0% code); promoted 2026-10-20** |
| 32 | **Pac-Man (U)** | **BYTE-IDENTICAL** | **partial (Pass 2 complete, Pass 3 partial — 119 operands, 0 residue); promoted 2026-10-20** |
| 34 | **Raid on Bungeling Bay (U)** | **BYTE-IDENTICAL** | **partial (Pass 2/3 partial, 64.6% code); promoted 2026-10-20** |
| 33 | **Pyramid (U)** | **BYTE-IDENTICAL** | **partial (Pass 2 complete, Pass 3 partial — 24 zero-page aliases, 32 named data tables, 0 residue, 39.6% code); promoted 2026-10-20** |
| 35 | **Raid on Bungeling Bay (U) [a2]** | **BYTE-IDENTICAL** | **partial (Pass 2 complete, Pass 3 partial — 15 zero-page aliases, 0 residue, 64.3% code); promoted 2026-10-20** |
| 30 | **Mario Bros (JU)** | **BYTE-IDENTICAL** | **partial (Pass 2 complete, Pass 3 partial — 25 zero-page aliases, 35 named data tables, 0 residue, 78.4% code); promoted 2026-10-20** |
| 29 | **Hogan's Alley (JU)** | **BYTE-IDENTICAL** | **partial (Pass 2 complete, Pass 3 partial — 60 semantic zero-page aliases, 34 named data tables, 0 residue, 49.1% code); promoted 2026-10-20** |
| 36 | Urban Champion (JU) | BYTE-IDENTICAL | complete; symbols applied 2026-10-19 (70 operands) |

Row 28 (`Golf (JU)`, still in `_wip/`) rebuilds cleanly at the whole-ROM
level as of 2026-10-20. It has Pass 1 done and is at substantial Pass 2.
Promotion into the numbered inventory, CDL-backed reclassification of the remaining
data, and a real power-on flow `README.md` per project are the open work for it;
the other 38 `_wip/` projects are Pass 0 skeletons and need Pass 1 from scratch.
See **`WIP.md`**.

Use `_tools/verify_pass1.py` to re-check any of this at any time; it rebuilds each
project and re-traces it, and reports `TRUNCATED` when a project's committed split
claims less code than the tracer can reach.