Pass 3 named the 10 data regions in prg.s, then the project was promoted
out of _wip/ so `make` now proves header + PRG + CHR against the original
ROM instead of only the PRG bank.
Data regions named:
LevelPtrTable $C000-$C03B (60 B) level header data
ObjectPtrTable $C03C-$C043 (8 B) 4 pointer pairs
LevelDataPtrTable $C044-$C79D (1882 B) level data pointers
SpriteInitPtrTable labelled at $C4B0 see residue note
UnreachedCode_D650 $D650-$D696 (71 B) unreached code
UnreachedCode_E144 $E144-$E165 (34 B) unreached code
MusicDataTable $F55B-$FA47 (1261 B) music/sound data
APUDataTable $FAE6-$FB74 (143 B) APU pulse/noise tables
SfxDataTable $FE59-$FFEF (407 B) sound-effect data
VectorTable $FFF6-$FFFF (10 B) padding + NMI/RESET/IRQ
Promotion (per the AGENTS.md checklist):
- git mv "_wip/Donkey Kong (JU)" "Donkey Kong (JU)"
- add copilot/rom.nes -> ../Donkey Kong (JU).nes symlink
- add header.s / chr.s (one-line .incbin of header.bin / chr.bin)
- linker.cfg gains HEADER ($0000/16 B) and CHR ($0000/8 KB)
- Makefile switched from `cmp reconstructed_prg.bin prg.bin` to
`cmp reconstructed.nes rom.nes`
- no _tools path change (this Makefile never referenced _tools/)
and no `make regen` pipeline exists for it
Doc corrections:
- project OVERVIEW.md said Mirroring Vertical; header byte 6 = $00
means Horizontal (the root index was right) — fixed
- root OVERVIEW.md: row 18 now BYTE-IDENTICAL, tier paragraph and
summary table refreshed (they had drifted around the Lunar Pool and
Urban Champion promotions), new per-project detail entry
- counts corrected to 19 top-level / 17 _wip in OVERVIEW.md,
TODO.md and AGENTS.md
Residue recorded rather than guessed:
- Pass 2 is partial: 919 Label_ definitions remain (214 semantic
labels applied); noted in TODO.md so nobody reads the promotion as
full semantic naming
- SpriteInitPtrTable's label sits at $C4B0: the routine at $C807 reads
$C4A7,x/$C4A8,x, but that table starts mid-row and a label there
would split the canonical 16-byte audit-comment line
Verification:
make clean && make -> "Byte-identical ROM verified."
verify_pass1.py -> 19/19 top-level build, Donkey Kong (JU) OK
(6014 instr / 12505 B), all comments canonical
Doc-drift sweep: build tiers, mirroring, and stale status tails
Reconciled the docs against verified reality after the Lunar Pool / Urban
Champion / Donkey Kong (JU) promotions and the 2026-10-19 audit-comment
standardization. No source behaviour changed except the two build fixes below.
Build tier (whole-ROM vs PRG-only)
- AGENTS.md: the 17 `_wip/` projects are real disassemblies at the PRG-build
tier, not "skeletons"; header.s/chr.s/rom.nes are promotion additions;
verify_pass1.py covers the top-level projects.
- Root OVERVIEW.md: `_wip` prose, audit-comment narrative and summary table
refreshed (37.5% figure, SEEDED vs OK wording, re-trace false alarm).
- Promoted projects whose build blocks still claimed `make` emits
`reconstructed_prg.bin` compared to `prg.bin` (Balloon Fight, Baseball,
CIRCUS, Clu Clu Land, Excitebike, NES PowerPad, Pac-Man (USA), Tennis):
now describe the whole-ROM `reconstructed.nes` vs `rom.nes`.
- Lunar Pool / Urban Champion / CIRCUS also had stale `cd "_wip/..."`
build paths and "Promotion" items; retargeted to their top-level folders.
Mirroring (header byte 6 bit 0: 0 = Horizontal, 1 = Vertical)
- Corrected DK Jr. prose "horizontal mirroring (flag 6 = $01)" -> vertical,
and both `_wip/Pac-Man` variant notes "Both use vertical mirroring" ->
horizontal (both are byte-6 = $00).
- Re-audited every project OVERVIEW: 0 rows and 0 prose claims now disagree.
Stale status tails
- Retitled/restatused the `_wip` OVERVIEWs to their real `prg.s` (Golf,
Ice Climber (U), Lode Runner, Millipede, Pac-Man Tengen, Pac-Man (U),
Popeye 0/1, Raid, Raid a2, Hogan's Alley, Mario Bros); Golf's
skeleton-era contents rows and Next Steps corrected.
- Dropped the skeleton-era "## Next Steps (per `PROMPTS.md`)" heading and
the "(from the skeleton)" wording across all project OVERVIEWs.
- Rewrote Lunar Pool / Urban Champion Next Steps (both already Pass 1-3
complete and promoted; their tails still described pending Pass 2 and
promotion); fixed root row 13 (Wild Gunman) and row 20 (Duck Hunt).
Also lands two code fixes carried with this sweep:
- `_wip/Hogan's Alley (JU)`: $E9F1-$E9FD and $EA13-$EA14 reclassified as
data with canonical audit comments (the seeded build had decoded a data
table base as code, breaking the build since 2ae09f7). `make` ->
BYTE-IDENTICAL again; reconstructed_prg.bin/.lbl refreshed.
- `_wip/Pyramid (U)`: `Label_D72E` -> `NMI:` (byte-identical).
Verification:
make (Hogan's Alley, Pyramid) -> BYTE-IDENTICAL, BYTE-IDENTICAL
_tools/verify_pass1.py -> 19/19 build, all canonical,
"No truncated or unfaithful Pass 1"
mirroring audit (rows + prose) -> 0 mismatches
Donkey Kong (JU): complete Pass 2 — all 919 Label_ definitions named
The last non-zero Label_ residue in the repo is now gone. Every one of the
919 address-derived definitions in copilot/prg.s is replaced:
* 319 routine entry points (jsr/jmp targets):
- 102 named from observed behaviour (LoadSpriteInitPointerToZp00 $C807,
CopyVramDataToBuffer $CBDF, CheckSpriteListCollision $D8AD,
UpdateRandomSeed $F4ED, ReadControllers $F50E, UpdateSoundEngine $FA48, ...)
- 217 left as SubC<addr> — honest residue where the body is too
context-dependent to name without guessing (Golf: 108, Mario Bros: 223)
- the 77 already-named entries untouched
* 600 internal branch targets named <Routine>_Block / <Routine>_Block_n in
address order within their owning routine (DK Jr./Balloon Fight convention).
Ownership is control-flow containment, so a loop that physically precedes
its own entry lands correctly (FlushPpuBuffer_Block $F1EC under $F228).
* Two proposal collisions disambiguated by indexing zero-page slot:
UpdateObjectListZp5D/DispatchObjectStateZp5E ($DA16/$DA4C) vs
UpdateObjectListZpAE/DispatchObjectStateZpAF ($E1E9/$E250).
jsr/jmp operands stay numeric (Wild Gunman style); only branch operands are
symbolic. Applied with _tools/pass2.py apply (919 defs + 2,622 refs rewritten,
comments re-aligned); the ROM still rebuilds byte-identically and
verify_pass1.py reports 19/19 canonical with no truncated split.
Docs synced: project OVERVIEW.md gains a Pass 2 Details section, root
OVERVIEW.md rows + conventions, TODO.md section 4 closed. dk_full_map.tsv now
records the complete applied map (its zp rows remain unapplied proposals).
_wip status correction: five false "Pass 2 complete" claims + map audit
The `_wip` tier's "Pass 2 complete" headers counted their draft maps' rows, not
the names actually present in `prg.s`, and described the count of *neutral*
`ZpXX` slots in `locals.inc` as "zero-page semantic aliases". Verified against
the sources and corrected in the root inventory rows, the project OVERVIEWs and
TODO:
project named/total Label_ left drafted map
Pinball (JU) 180 / 681 501 210 rows, 179 applied
Ice Climber (JE) 76 / 973 897 255 rows, 76 applied
Donkey Kong Jr. Math 64 / 1035 971 243 rows, 62 applied
Duck Hunt (JUE) 31 / 472 441 272 rows, 31 applied
Ice Climber (U) 2 / 973 971 none - Pass 2 not started
No `_wip` project is Pass 2 complete. Ice Climber (U) was the worst case: the
2026-10-19 sweep itself restated it "Pass 2 complete" while describing its 971
`Label_` definitions in the same paragraph - a copy-paste from (JE); (U) has no
map file at all.
Drafted maps audited row by row against the committed split: they are not
applicable. 100/243 (DK Jr. Math), 96/255 (Ice Climber (JE)) and 17/210
(Pinball) rows point at addresses that are not instruction boundaries - they
were built against an older code/data split - while most of the rest are
unlabelled boundaries that no operand references, or (Duck Hunt) competing
candidate names for one label (`Label_C2BF` alone carries 205). Rows that are
both insertable and corroborated by control flow: 0 in every map. Recorded as
stale and kept for provenance; Pass 2 here needs a fresh map derived from the
committed split.
Also corrected while verifying:
- Mario Bros entry counts (docs said 252 / 90 + 165 / 477 sites / 156 neutral
slots; the file holds 262 distinct `jsr`/`jmp` targets = 39 semantic + 223
`SubC<addr>`, 478 sites, 151 slots).
- root `_wip` prose line/label ranges (4,482-17,180 lines, 192-971 `Label_`,
11,126 total) and the Ice Climber code figure (74.6% / 6,112 instr, not
74.7% / 6,113).
- TODO §4 re-scoped to the promoted tier, with the `_wip` residue table added.
Verification: `make` across all 17 `_wip` projects -> BYTE-IDENTICAL (17/17);
`_tools/verify_pass1.py` -> 19/19 build, all canonical, "No truncated or
unfaithful Pass 1 found". No source bytes changed.
Balloon Fight (JU): apply locals.inc/symbols.inc names to prg.s (Pass 3)
Substitutes symbol names for 922 numeric operands: 125 hardware registers
(symbols.inc) and 797 of 813 zero-page/RAM operands (locals.inc). The 15
multi-alias addresses were resolved per routine; 16 operands stay numeric
because $13 is used there as a plain high-byte scratch beside Temp12 and
none of its three aliases fits.
- _tools/apply_symbols.py: the substitution tool (dry run by default;
--sites supplies per-routine choices for multi-alias addresses, --report
lists the residue). Only the operand token is rewritten, so the
`; CPU:$.... PRG:.... XX XX` audit comments survive byte for byte.
- prg.s: operand tokens only. make prints "Byte-identical ROM verified."
- OVERVIEW.md (project): instruction quotes now match prg.s, new
alias-reuse table, and section 10 rewritten from the stale "497 Label_"
prose to the real naming state and the 16-site residue.
- OVERVIEW.md (root), TODO.md, AGENTS.md: status, counts, tool list.
verify_pass1.py: 19/19 OK, all audit comments canonical.
Bomberman (U): apply locals.inc/symbols.inc names to prg.s (Pass 3)
Substitutes 362 zero-page operands in copilot/prg.s with the names already
declared in copilot/locals.inc: 354 from single-name addresses and 8 from the
two multi-alias addresses, resolved per site:
$E0/$E1 IndirectPtrLo/Hi in the RAM-clear loop
(InitializeSystemAndRunMainLoop -> Main_WriteSoundDispatchIndex_C317,
which writes $00 across $0100-$07FF via (ptr),y),
SoundDelay0 (the base of the per-channel delay table, indexed by X)
in the sound engine;
No symbols.inc substitution was needed: copilot/prg.s contains no numeric
hardware operands ($2000-$4017) at all. All 362 operands were already written
with two hex digits, so no ca65 `a:` prefix was required.
make -> Byte-identical ROM verified. Operand token only; mnemonics, spacing and
the trailing `; CPU:$.... PRG:.... XX XX` audit comments are untouched.
Remaining numeric operands (758) address bytes that no .inc file names:
505 zero-page (133 addresses), 171 RAM $0100-$07FF (46 addresses) and 82
table reads in $8000+ (54 addresses).
Bomberman (U): substitute 24 in-file table labels at ROM operand sites
Uses the new `--labels` option of `apply_symbols.py` with the
ld65 `-Ln` output (`reconstructed.lbl`). Only labels that prg.s
actually defines and that live in the PRG (+) are considered,
so CHR/header segment labels cannot leak in.
24 numeric operands (`lda ,x`, `adc ,y`, etc.) now read
`lda SystemPaletteData,x`, `adc GameplayObjectClassTable,y`, etc.
All 24 point at exact label addresses; the remaining 58 ROM-space
numeric operands point at interior bytes or unlabelled tables and
stay numeric.
make -> Byte-identical ROM verified.
Bomberman (U): update docs for Pass 3 symbol application
- Project OVERVIEW.md: corrected source file from main.s to prg.s/header.s/chr.s;
output name from reconstructed_bomberman.nes to reconstructed.nes;
rewritten §10 Zero-Page/RAM Symbols table to match locals.inc (with aliases
and unnamed residue documented);
fixed §4 step 1/4 to use IndirectPtrLo/Hi and SoundDelay0 names;
fixed §11 InesHeader location (now header.s);
added §2 Pass 3 summary table;
added §13 notes on legacy main.s and Main_WriteSoundDispatchIndex_C317 misnomer.
- Root OVERVIEW.md §3: updated source line count (7,553), file list, and added
Pass 3 summary.
Both builds verified byte-identical.
Pass 3 symbol application to all 19 top-level projects (2026-10-19)
Ran _tools/apply_symbols.py --write on all 19 promoted projects to substitute
symbolic names from symbols.inc (hardware registers) and locals.inc (zero-page
RAM aliases, forward references) into prg.s operands. The tool preserves the
canonical audit comments (; CPU:$XXXX PRG:XXXX AA BB) and preserves byte
identity — all projects still rebuild byte-identical to their original ROMs.
Per-project operand substitutions:
Baseball (UE) 121 (85 single + 36 hardware)
Tennis (JU) 18 (18 single)
Pac-Man (USA) (Namco) 524 (524 single; 727 multi-alias residues)
CIRCUS 118 (38 single + 80 hardware; 23 multi-alias residues)
Wild Gunman (U) 76 (11 single + 65 hardware)
Joypad Test Cartridge (U) 47 (47 hardware)
NES PowerPad Test Card (U) 89 (89 hardware)
MUSCLE (U) 220 (91 single + 129 hardware)
Lunar Pool (U) 45 (18 single + 27 hardware)
Donkey Kong (JU) 75 (17 single + 58 hardware)
Urban Champion (JU) 70 (4 single + 66 hardware)
Already had symbols applied: Balloon Fight, Bomberman, Burger Time,
Clu Clu Land, Defender 2, Donkey Kong 3, Donkey Kong Jr.
Skipped: Excitebike (JU) — inline prg.s definitions conflict with locals.inc
values and source operands don't match ROM byte encodings; automatic
substitution breaks byte identity.
Documentation updated:
OVERVIEW.md — added Pass 3 symbol notes to all 19 project entries,
added Urban Champion as section #36
TODO.md — current state now reflects complete symbol application across
the promoted tier
Verification: python3 _tools/verify_pass1.py reports all 19 projects OK/SEEDED,
all canonical comments, no truncated or unfaithful Pass 1.
47 KiB
Disassembly Project Index — /home/tmerritt/Projects/disassembly/
This document provides a consolidated overview of all NES disassembly projects in this directory. Each project has its own folder containing a copilot/ subdirectory with the full source, build tooling, and — for every project except Donkey Kong 3 (JUE), which still needs one — an individual OVERVIEW.md (at the project folder root) 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 OVERVIEW.md files 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 | PRG-IDENTICAL (Pass 1 complete, Pass 2 partial — 64 of 1,035 labels named, 81.9% code) | $C4A9 / $C41E / $FFF0 |
| 20 | Duck Hunt (JUE) |
Japan / USA / Europe | 16 KB | 8 KB | Vertical | PRG-IDENTICAL (Pass 1 complete, Pass 2 partial — 31 of 472 labels named, 37.5% code) | $C086 / $C000 / $C000 |
| 21 | Golf (JU) |
Japan | 16 KB | 8 KB | Vertical | PRG-IDENTICAL (Pass 1+ substantial) | $C0A6 / $C000 / $C0C4 |
| 22 | Hogan's Alley (JU) |
Japan | 16 KB | 8 KB | Vertical | PRG-IDENTICAL (Pass 1 complete, 41.8% code, needs CDL reclass; build fixed 2026-10-19 — $E9F1 forced back to data) |
$C088 / $C000 / $C000 |
| 23 | Ice Climber (JE) |
— | 16 KB | 8 KB | Horizontal | PRG-IDENTICAL (Pass 1 complete, Pass 2 partial — 76 of 973 labels named, 74.6% code) | $C076 / $C014 / $FFF0 |
| 24 | Ice Climber (U) |
USA | 16 KB | 8 KB | Horizontal | PRG-IDENTICAL (Pass 1 complete, Pass 2 not started — 2 of 973 labels named, 74.6% code) | $C076 / $C014 / $FFF0 |
| 25 | Lode Runner (U) |
USA | 16 KB | 8 KB | Vertical | PRG-IDENTICAL (Pass 1 complete, 52.6% code) | $C02C / $C000 / $FFF9 |
| 26 | Mario Bros (JU) |
Japan | 16 KB | 8 KB | Vertical | PRG-IDENTICAL (Pass 1 complete, Pass 2 substantial) | $C07D / $C000 / $C000 |
| 27 | Millipede (U) |
USA | 16 KB | 8 KB | Vertical | PRG-IDENTICAL (Pass 1 complete, 74.6% code) | $C7F1 / $C735 / $FFF0 |
| 28 | Pac-Man (Tengen) (U) |
USA | 16 KB | 8 KB | Horizontal | PRG-IDENTICAL (Pass 1 complete, 19.5% code) | $C0FA / $C033 / $C16A |
| 29 | Pac-Man (U) |
USA | 16 KB | 8 KB | Horizontal | PRG-IDENTICAL (Pass 1 complete, 19.6% code) | $C0FA / $FF00 / $C16A |
| 30 | Pinball (JU) |
Japan | 16 KB | 8 KB | Horizontal | PRG-IDENTICAL (Pass 1 complete, Pass 2 partial — 180 of 681 labels named, 59.5% code) | $C1ED / $C000 / $C1ED |
| 31 | Popeye (JU) (PRG 0) |
— | 16 KB | 8 KB | Vertical | PRG-IDENTICAL (Pass 1 complete, 72.3% code) | $C701 / $C649 / $FFF0 |
| 32 | Popeye (JU) (PRG 1) |
— | 16 KB | 8 KB | Horizontal | PRG-IDENTICAL (Pass 1 complete, 72.3% code) | $C701 / $C649 / $FFF0 |
| 33 | Pyramid (U) |
USA | 16 KB | 8 KB | Vertical | PRG-IDENTICAL (Pass 1 done) | $D72E / $FF00 / $FF00 |
| 34 | Raid on Bungeling Bay (U) |
USA | 16 KB | 8 KB | Vertical | PRG-IDENTICAL (Pass 1 complete, 64.6% code) | $C04C / $C000 / $C2C0 |
| 35 | Raid on Bungeling Bay (U) [a2] |
— | 16 KB | 8 KB | Horizontal | PRG-IDENTICAL (Pass 1 complete, 64.3% code) | $C04C / $C000 / $C2C0 |
| 36 | Urban Champion (JU) | Japan | 16 KB | 8 KB | Vertical | BYTE-IDENTICAL (Pass 3 complete, 33.9% code) | $CA91 / $CA00 / $CA00 |
All 36 are mapper 0 / 16 KB PRG / 8 KB CHR, battery-backed, no trainer.
Rows 1-18 are BYTE-IDENTICAL: make compares the whole reconstructed ROM
against copilot/rom.nes. Rows 19-35 are PRG-IDENTICAL: their Makefiles
compare only reconstructed_prg.bin against prg.bin, so header and CHR are
not yet proven to rebuild. Treat those as unverified outside the PRG. Row 36
(Urban Champion) is also BYTE-IDENTICAL — it was promoted while still numbered
at the tail of the _wip block, so the tier split is by row ranges 1-18 + 36
versus 19-35, not a single cut.
How to read this table. The vectors are the three little-endian words at the end of the
16 KB PRG ($FFFA-$FFFF in the $C000 mirror) — not fields in the iNES header, whose bytes
0-9 carry only sizes, mirroring and mapper. Regenerate the whole column with:
python3 - <<'EOF'
import os
for p in sorted(d for d in os.listdir('.') if os.path.isdir(os.path.join(d, 'copilot'))):
rom = open(f"{p}/copilot/rom.nes", 'rb').read()
prg = rom[16:16 + rom[4]*16384]; vo = len(prg) - 6
v = [prg[vo+i] | (prg[vo+i+1] << 8) for i in (0, 2, 4)]
print(f"{p:30s} {'Vertical' if rom[6] & 1 else 'Horizontal':10s} "
+ " / ".join("$%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:
Balloon Fight (JU)/ - ROM:
balloon.nes(24,592 bytes) - Source:
copilot/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
.incbinspans were converted to explicit classified bytes (TrailingFillBeforeApuTablesat $F4C5,SoundEngineTailBytesat $F5FC), so no ROM byte is hidden - Pass 3 symbols (2026-10-19): every operand
symbols.inc/locals.incdefines is now named inprg.s— 125 hardware-register operands and 797 of 813 zero-page/RAM operands. The 15 multi-alias addresses were resolved per routine (--sitesin_tools/apply_symbols.py). 16 operands are left numeric:$13used as a plain high-byte scratch besideTemp12, where none of its three aliases fits. Rebuild stays byte-identical. - Details:
Balloon Fight (JU)/OVERVIEW.md
2. Baseball (UE)
- Folder:
Baseball (UE)/ - ROM:
baseball.nes(24,592 bytes) - Source:
copilot/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.incvia_tools/apply_symbols.py— zero residue. Rebuild stays byte-identical. - Details:
Baseball (UE)/OVERVIEW.md
3. Bomberman (U)
- Folder:
Bomberman (U)/ - ROM:
bomberman.nes(24,592 bytes) - Source:
copilot/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 $E4vsdec $54) — resolved by addingRandomStateAlt = $E4tolocals.incalongsideRandomState0 = $54(zero-page reuse); also renamedControllerState→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 fromreconstructed.lbl; 0 hardware substitutions needed. Residue: 758 unnamed operands (179 distinct addresses). - Details:
Bomberman (U)/OVERVIEW.md
4. Burger Time (U)
- Folder:
Burger Time (U)/ - ROM:
Burger Time (U) [!].nes(24,592 bytes) - Source:
copilot/prg.s(9,323 lines),copilot/header.s,copilot/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,seiprologue), 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)/OVERVIEW.md
5. Clu Clu Land (JU)
- Folder:
Clu Clu Land (JU)/ - ROM:
rom.nes(24,592 bytes) - Source:
copilot/main.s(9,150 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
bplbranch to undefined label at CPU $FAB4 — replaced withbne *-$1Bto produce originald0 e3bytes (disassembler mislabeledbneasbpl) - Details:
Clu Clu Land (JU)/OVERVIEW.md
6. Defender 2 (U)
- Folder:
Defender 2 (U)/ - ROM:
Defender 2 (U).nes(24,592 bytes) - Source:
copilot/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_CA6Aat $CA6A) waiting on NMI flag, side-scrolling gameplay ($C073–$C324 family), PPU streaming ($F20B–$F7C0), audio engine ($E642–$F7C0) with dispatch table ($E6AD) - Build fix: Same
bpl→bne *-$1Bfix at CPU $E811 as Clu Clu Land (disassembler mislabeledbneasbpl) - Details:
Defender 2 (U)/OVERVIEW.md
7. Excitebike (JU)
- Folder:
Excitebike (JU)/ - ROM:
rom.nes(24,592 bytes) - Source:
copilot/prg.s(14,111 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 *-$1Bfix at CPU $FAB4 (same pattern as Clu Clu Land/Defender 2) - Details:
Excitebike (JU)/OVERVIEW.md
8. Tennis (JU)
- Folder:
Tennis (JU)/ - ROM:
Tennis (JU).nes(24,592 bytes) - Source:
copilot/prg.s(9,268 lines) - Linker: PRG at $C000, 16 KB; single segment
- Vectors: NMI → $C07D (
NmiHandler), RESET → $C000 (Reset), IRQ → $C000 (Resetreused) - Key subsystems: NMI-synchronized main loop (
MainLoopat $C04F), game state machine viaMainStateHandlerTable($C101, 12 states), game mode state machine viaGameModeStateTable($CAD7, 8 states), object/sprite system with fixed-point physics, audio engine ($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.incvia_tools/apply_symbols.py— zero residue. Rebuild stays byte-identical. - Details:
Tennis (JU)/OVERVIEW.md
9. Pac-Man (USA) (Namco)
- Folder:
Pac-Man (USA) (Namco)/ - ROM:
rom.nes(24,592 bytes) - Source:
copilot/prg.s(9,268 lines) - Linker: PRG at $C000, 16 KB; single segment
- Vectors: NMI → $C10E (
NmiHandler), RESET → $C033 (Reset;locals.incdefinesResetOffset = $C033), IRQ → $C17E (IrqHandler) - Key subsystems: NMI-synchronized main loop (
MainLoopat $C04F), game state machine viaMainStateHandlerTable($C101, 12 states), game mode state machine viaGameModeStateTable($CAD7, 8 states), object/sprite system with fixed-point physics, audio engine ($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.incvia_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)/OVERVIEW.md
10. Donkey Kong 3 (JUE)
- Folder:
Donkey Kong 3 (JUE)/ - ROM:
Donkey Kong 3 (JUE).nes(24,592 bytes) - Source:
copilot/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; theprg.sheader block records it as "Pass 2 control-flow entry at CPU $C08D"), RESET → $C000 (Reset), IRQ → $C000 (Resetreused) - 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.sintoheader.s,prg.s,chr.s; addedRandomStateAlt = $E4fordec $E4at CPU $E71B (zero-page reuse withRandomState0 = $54). 2026-10-16 — one-byte branch-target bug fixed: the project was recorded as BYTE-IDENTICAL but had never built byte-identical. Thebneat CPU $C14C (PRG $014C) was annotatedD0 12(target $C160) but assembled asD0 0D, because it was labelledStoreSelectedPlayerAndScreenFlags($C15B) instead of the routine actually at $C160. Retargeted toClearAudioSetGameMode— which is also the semantically correct target for a "mode != $01" test.cmpnow passes. - Details:
Donkey Kong 3 (JUE)/copilot/OVERVIEW.md
11. Donkey Kong Jr. (JU)
- Folder:
Donkey Kong Jr. (JU)/ - ROM:
Donkey Kong Jr. (JU).nes(24,592 bytes) - Source:
copilot/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 (
makeincopilot/). Pass 1 verified complete 2026-10-16 — a full byte-accounting audit ofprg.sconfirms 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.incbinremains. 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 theDeferredTaskHandlerTabledispatch at $BFFE). Pass 2/3 naming is complete; Pass 3 tables are named (DeferredTaskHandlerTable,HudDigitDescriptorTable, …) - Details:
Donkey Kong Jr. (JU)/OVERVIEW.md
12. CIRCUS
- Folder:
CIRCUS/ - ROM:
rom.nes(24,592 bytes) - Source:
copilot/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 (
makeincopilot/). 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.incvia_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/OVERVIEW.md
13. Wild Gunman (U)
- Folder:
Wild Gunman (U)/ - ROM:
rom.nes(24,592 bytes) - Source:
copilot/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 (reusesReset) - 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 (
makeincopilot/compares the whole ROM: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'spla-based computed goto puts the jump table inline right after eachjsr $C341) and filed ~4.9 KB of real code as.bytedata. 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 (zeroLabel_Cxxxx/SubCxxxxremain), routine headers on every entry point, zero-page aliases inlocals.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.incvia_tools/apply_symbols.py— zero residue. Rebuild stays byte-identical. - Details:
Wild Gunman (U)/OVERVIEW.md
14. Joypad Test Cartridge (U)
- Folder:
Joypad Test Cartridge (U)/ - ROM:
rom.nes(24,592 bytes) - Source:
copilot/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 (reusesReset) - 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 atRetAddrUpdate($CDC8) for runtime-computed dispatch;VramWrite($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
$C09EonDCP $3C20($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 --undocumentedsupplies the 105 undocumented NMOS opcodes; ca65 V2.19 encodes none of them, so the 4 affected instructions are emitted as explicit.bytewith the disassembly in the comment. Pass 2 then renamed all 202 labels (zeroLabel_Cxxxxleft) and rewrote all 202 routine headersr all labels, semantic naming for key routines, zero-page aliases inlocals.inc(VramPtrLo=$00,PpuCtrlShadow=$EF,FrameCounterLo=$53, etc.) - Pass 3 symbols (2026-10-19): 47 hardware operands substituted from
symbols.incvia_tools/apply_symbols.py— zero residue. Rebuild stays byte-identical. - Details:
Joypad Test Cartridge (U)/OVERVIEW.md
15. NES PowerPad Test Card (U)
- Folder:
NES PowerPad Test Card (U)/ - ROM:
rom.nes(24,592 bytes) - Source:
copilot/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 (reusesReset) - 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.incvia_tools/apply_symbols.py— zero residue. Rebuild stays byte-identical. - Details:
NES PowerPad Test Card (U)/OVERVIEW.md
16. MUSCLE (U)
- Folder:
MUSCLE (U)/ - ROM:
M.U.S.C.L.E. (U).nes(24,592 bytes);copilot/rom.nesis a relative symlink../M.U.S.C.L.E. (U).nes - Source:
copilot/prg.s(Pass 1/2/3 output, with 42 bytecode listings above the.bytedata) - 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 bareRTIthat doubles as the NMI epilogue). Vectors themselves sit in the $C000 mirror at $FFFA. - Key subsystems: bytecode VM — 40 opcodes at
$C8-$EFhandled through a table at$9237, everything else a literal operand. Gameplay dispatches through three jump tables plus two zero-pagejmp (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$AC82with a 12-byte fill table at$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
$C000linker assumption was wrong — RESET is$8000, solinker.cfghad to move.copilot/Makefiletool paths were../../../_tools/while in_wip/; promotion to top-level required../../_tools/.make regen(pass1→pass2→pass3) reproducesprg.sbyte-for-byte. - Pass 3 symbols (2026-10-19): 220 operands substituted (91 single-name + 129 hardware) from
symbols.inc/locals.incvia_tools/apply_symbols.py— zero residue. Rebuild stays byte-identical. - Details:
MUSCLE (U)/OVERVIEW.md
17. Lunar Pool (U)
- Folder:
Lunar Pool (U)/(promoted out of_wip/2026-10-18 bygit mv, so the relativecopilot/rom.nessymlink is live and tool paths are../../_tools/) - ROM:
Lunar Pool (U).nes(24,592 bytes) - Source:
copilot/prg.s(5,300 instructions, 67.6% code / 11,077 bytes; 705 labels, zeroLabel_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 (barerti, 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/addedheader.s,chr.s, HEADER/PRG/CHRlinker.cfg, and whole-ROMcmp; 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.incvia_tools/apply_symbols.py— zero residue. Rebuild stays byte-identical. - Details:
Lunar Pool (U)/OVERVIEW.md
18. Donkey Kong (JU)
- Folder:
Donkey Kong (JU)/(promoted out of_wip/2026-10-19 bygit mv, so the relativecopilot/rom.nes → ../Donkey Kong (JU).nessymlink survived) - ROM:
Donkey Kong (JU).nes(24,592 bytes) - Source:
copilot/prg.s(6,014 instructions, 76.3% code / 12,505 bytes; 1,015 labels with zeroLabel_residue, 145 zero-page slots with neutralZpXXnames, 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 overMusicDataTable($F55B),APUDataTable($FAE6),SfxDataTable($FE59) - Pass 2 (2026-10-19): all 919
Label_XXXXdefinitions named — 102 new semantic routine names + 217SubC<addr>entry names (honest residue) + 600 derived<Routine>_Block[_n]internal branch targets;jsr/jmpoperands stay numeric (Wild Gunman (U)style). Applied with_tools/pass2.py apply;makestill byte-identical - Build fix: none at PRG level — it was PRG-identical in
_wip/and stayed byte-identical through Pass 3. Promotion addedheader.s,chr.s, a HEADER/PRG/CHRlinker.cfg, therom.nessymlink, and the whole-ROMcmp; no_toolspath change (the Makefile never referenced_tools/) and nomake regentarget. Mirroring was recorded as Vertical in the project 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.incvia_tools/apply_symbols.py— zero residue. Rebuild stays byte-identical. - Pass 3 symbols (2026-10-19): 75 operands substituted (17 single-name + 58 hardware) from
symbols.inc/locals.incvia_tools/apply_symbols.py— zero residue. Rebuild stays byte-identical. - Details:
Donkey Kong (JU)/OVERVIEW.md
36. Urban Champion (JU)
- Folder:
Urban Champion (JU)/ - ROM:
Urban Champion (JU).nes(24,592 bytes) - Source:
copilot/prg.s(~4,000 lines) - Linker: PRG at $C000, 16 KB; single segment
- Vectors: NMI → $CA91 (
NmiHandler), RESET → $CA00 (Reset), IRQ → $CA00 (reusesReset) - Key subsystems: NMI-driven frame loop with simple fight game logic; minimal code (33.9%)
- Build fix: None needed; byte-identical out of the box
- Pass 3 symbols (2026-10-19): 70 operands substituted (4 single-name + 66 hardware) from
symbols.inc/locals.incvia_tools/apply_symbols.py— zero residue. Rebuild stays byte-identical. - Details:
Urban Champion (JU)/OVERVIEW.md
_wip/ Projects
These 17 ROMs are listed as rows 19-35 of the Project Inventory above, so their vectors and mirroring are in one place rather than a second table that can drift.
Each carries a real disassembly, not a skeleton: 4,482–17,180 lines of prg.s
with 192–971 address-based Label_ definitions apiece — 11,126 in total.
Fifteen of the seventeen also carry canonical ; CPU:$xxxx PRG:xxxx AA BB
audit comments; the two exceptions predate
that convention — Golf (JU) uses ; C007: AD 02 20 and Pyramid (U) a
; PRG:$172E 48 form. They verify at PRG level only — their Makefiles run
cmp reconstructed_prg.bin prg.bin, not a whole-ROM compare, which is why the
inventory marks them PRG-IDENTICAL rather than BYTE-IDENTICAL. None keeps the
header/CHR as linkable source: copilot/ holds the raw header.bin/chr.bin
splits, with no header.s, chr.s or HEADER/PRG/CHR linker.cfg. Promoting one
to the top level therefore means adding a copilot/rom.nes (a relative symlink
survives the git mv), adding those three files (copy the shape from
Burger Time (U)/copilot/), switching the Makefile to a whole-ROM compare, and
moving the ../../../_tools/ paths to ../../_tools/. Lunar Pool (U) went
through exactly that on 2026-10-18 and Donkey Kong (JU) on 2026-10-19 (Pass 3
done, whole ROM byte-identical); DK (JU) needed no _tools path change because
its Makefile never referenced _tools/.
Pass 1 is done in all 17, and the inventory rows give the authoritative
per-project status. No _wip project is Pass 2 complete. The furthest
along are Pinball (180 of 681 label definitions named, plus 40 Pass 3 data
regions drafted but unapplied) and Mario Bros (262 call entry points named —
39 semantic + 223 SubCxxxx), and both still carry hundreds of address-based
Label_ definitions; the other 15 are Pass 1 with partial or no semantic
naming, and none has semantic zero-page aliases. Five headers that read
"Pass 2 complete" before 2026-10-19 (Donkey Kong Jr. Math, Duck Hunt, Ice
Climber (JE), Ice Climber (U), Pinball) had counted their draft maps' rows
rather than the names actually present in prg.s; those claims are corrected,
and the maps themselves are stale and unapplied (audited per project — see each
project's OVERVIEW.md). All 17 currently build cleanly at the PRG level.
Each project also owes a real power-on flow OVERVIEW.md — the 2026-10-19
sweep corrected their status headers to match the actual sources, but most still
lack the flow analysis the top-level projects carry.
Notable vector/header observations for Pass 1 work:
- Pac-Man (U) RESET at
$FF00(vector-page tail), while the Tengen variant RESETs at$C033— different builds confirmed (PRG bytes differ). - Lunar Pool (U) NMI
$FF65/ IRQ$FF64are 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)/OVERVIEW.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 barertijust before the NMI handler, so IRQs are ignored). There is nojmp ($7961)RAM-pointer gate (an earlier claim): those three sites fell out of decoding two bytes into the word "player".$CBDC/$CBC9is a print-inline-string-and-return-after-it helper, so ajsr $CBDCis always followed by a$81-prefixed,$00-terminated string ("player", "shot", "game over", "hiscore__", "perfect_"). The split was re-derived from a Mesen CDL capture (10,028 bytes Code): now **5,300 instructions / 11,077 bytes (67.6%)**, 5,301 data bytes and the six vector bytes as.word. Pass 2 named all **705** labels —Label_is gone from the file — and Pass 3 named 33 tables plus the zero-page aliases (38 semantic, 66 neutral, ten former phantom aliases deleted). Residue, recorded rather than guessed: 73 bytes of *reachable* code are still.byte($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. SeeLunar Pool (U)/OVERVIEW.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) — already at Pass 1: interesting unlicensed Sachen boot ($4100 mapper pokes, "AV" stack-byte check, two queued-event dispatchers). See its
OVERVIEW.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/OVERVIEW.md. - Joypad Test Cartridge (U) — Pass 3 complete: minimal code (23.4%), data-heavy test cartridge. Data region
$CF06–$FFFFbroken into 20 named sub-blocks; VRAM command stream opcode set decoded viaRetAddrUpdatereturn-address modification trick at$CDC8. SeeJoypad Test Cartridge (U)/OVERVIEW.md. - Wild Gunman (U) — Pass 1 redone, Pass 2/3 complete: NMI-driven frame loop. Gates its code behind runtime computed-goto tables — see the
prg.sheader block and itsOVERVIEW.md. - Mario Bros (JU) — Pass 1 complete (72.2% code), Pass 2 substantial: 262 call entry points named (39 semantic + 223
SubCxxxxaddress-based) — verified 2026-10-19; the earlier "252 (90 + 165)" was wrong; 667 internalLabel_Cxxxxbranch targets remain. Code is gated behind stack-based indirect dispatch at$CD9Eand a 20-entryJSRthunk table at$C5A3. Audio routines in$F8xx-$F9xxclearly identifiable from APU register writes. See_wip/Mario Bros (JU)/OVERVIEW.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
rtior 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
.cfgmemory 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/.resdata 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 folder contains:
copilot/— disassembly source, build config, and build artifactsOVERVIEW.md(at the project folder root) — detailed per-project power-on execution flow analysis<rom>.nes— original NES ROM image (for reference)
To rebuild any project:
cd /home/tmerritt/Projects/disassembly/<Project>/copilot
make
To verify byte-identity:
make verify # (where supported by the Makefile)
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:
- 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.
- No runtime dispatch. It followed only vectors and direct
jsr/jmp/branch targets. Games here dispatch through computed jumps —jmp ($0014), thepla-based inline-table gotos in Wild Gunman (Label_C341), and task tables like Donkey Kong Jr.'sDeferredTaskHandlerTableat $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 19 top-level projects — it selects folders
that carry a copilot/rom.nes, so the 17 _wip/ projects are not covered (they
are checked by plain make at the PRG level). Current run, 2026-10-19: every
project builds, 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/, 15 of the 17 also use the canonical spelling; the two stragglers
are Golf (JU) (; C007: AD 02 20) and Pyramid (U) (; PRG:$172E 48).
Bringing those two up to canonical is Pass 2 work for them, 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 19 top-level 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
The 19 numbered projects below are promoted out of _wip/ and rebuild byte-identical
to their original ROMs (rows 1-18 plus row 36 — Urban Champion kept its tail number
when it was promoted). The 17 _wip/ projects (rows 19-35) verify at PRG level only —
see "_wip/ Projects" below.
| # | 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 |
| 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) |
| 36 | Urban Champion (JU) | BYTE-IDENTICAL | complete; symbols applied 2026-10-19 (70 operands) |
Rows 19-35 (_wip/) all rebuild cleanly at PRG level. All 17 have Pass 1 done and
several are at Pass 2 (see the rows above); promotion into the numbered inventory,
CDL-backed reclassification of the remaining data, and a real power-on flow
OVERVIEW.md per project are the open work for them.
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.