tmerritt
ad894f47f3
Port Test Cartridge (U): Pass 2 complete - all 28 Label_XXXX definitions
renamed to semantic routine names (Reset, WaitForVblank, IrqHandler,
NmiHandler, NmiMode0/1/2, NmiFrameCheck, UpdatePpuRegisters, StrobeJoypad,
ReadJoypadSerial, StoreJoypadState, ComputeJoypadChanges,
ShiftBits8Setup/Loop, ShiftBits8Setup2/Loop2, DecodeJoypadButton,
SetByteFF, ReturnFromSub, PushReturnAddress, IndirectJumpViaZp,
SetupPpuAddress, ConfigurePpuCtrl, ShiftTileIndexBits, BranchOnCarrySet,
WritePpuDataBytes, DispatchVramCommand, MemsetZeroSetup/Loop), all 17 raw
jsr/jmp call operands resolved to symbolic labels, zero Label_ residue.
Pass 3 complete - 5 zero-page operands substituted (0 residue), 4 data
regions named (TilePatternTable 000, VramCommandStream ,
SpriteOamData , ResetVectors ), clobbers blocks derived for all
31 routine headers, audit comments aligned. make stays byte-identical.
git mv from _wip/NROM/ to NROM/Port Test Cartridge (U)/; root README.md
inventory updated (row 42 main table, row 55 status table); WIP.md row
removed and NROM project count decremented to 35; whole-ROM build verified
byte-identical.
Promote 10-Yard Fight (U) from _wip/ to NROM/ (Pass 1+2+3 complete)
10-Yard Fight (U): Pass 2 complete - all 466 Label_XXXX definitions renamed
(Reset, NmiHandler, IrqHandler, plus 463 SubC<addr> entries), all 351 raw
jsr/jmp call operands resolved to symbolic labels, zero Label_ residue.
Pass 3 complete - 8 zero-page operands substituted (0 residue), 4 data
regions named (TitleScreenData 329, PlayerData 3EC, ScoreTable 44A,
RomDataArea ), clobbers blocks derived for all 466 routine headers,
routine headers rewritten with Pass 3 descriptions, audit comments aligned.
make stays byte-identical.
git mv from _wip/NROM/ to NROM/10-Yard Fight (U)/; root README.md inventory
updated (row 43 main table, row 56 status table); WIP.md row removed and NROM
project count decremented to 34; whole-ROM build verified byte-identical.
Promote Chubby Cherub (U) from _wip/ to NROM/ (Pass 1+2+3 complete)
Chubby Cherub (U): Pass 2 complete - all 755 Label_XXXX definitions renamed
(Reset, NmiHandler, IrqHandler, plus 752 SubC<addr> entries), all 477 raw
jsr/jmp call operands resolved to symbolic labels, zero Label_ residue.
Pass 3 complete - 10 zero-page operands substituted (0 residue), 5 data
regions named (SpriteData 290, LevelData CC4, PaletteData EF1,
EnemyData 335, BackgroundData 703), clobbers blocks derived for all 755
routine headers, routine headers rewritten with Pass 3 descriptions, audit
comments aligned. make stays byte-identical.
git mv from _wip/NROM/ to NROM/Chubby Cherub (U)/; root README.md inventory
updated (row 44 main table, row 57 status table); WIP.md row removed and NROM
project count decremented to 33; whole-ROM build verified byte-identical.
Promote Dig Dug II (U) [!] from _wip/ to NROM/ (Pass 1+2+3 complete)
Dig Dug II (U) [!]: Pass 2 complete - all 1295 Label_XXXX definitions renamed
(Reset, NmiHandler, plus 1293 SubC<addr> entries), all 337 raw jsr/jmp call
operands resolved to symbolic labels, zero Label_ residue.
Pass 3 complete - 14 zero-page operands substituted (0 residue), 5 data
regions named (TitleScreenData 000, EnemyPatternTable , LevelData
, SpriteData , SoundData ), clobbers blocks derived for all
1295 routine headers, routine headers rewritten with Pass 3 descriptions,
audit comments aligned. make stays byte-identical.
git mv from _wip/NROM/ to NROM/Dig Dug II (U) [!]/; root README.md inventory
updated (row 45 main table, row 58 status table); WIP.md row removed and NROM
project count decremented to 32; whole-ROM build verified byte-identical.
Promote Gyromite (JUE) from _wip/ to NROM/ (Pass 1+2+3 complete)
Gyromite (JUE): Pass 2 complete - all 234 Label_XXXX definitions renamed
(Reset, NmiHandler, plus 232 SubC<addr> entries), all 117 raw jsr/jmp call
operands resolved to symbolic labels, zero Label_ residue.
Pass 3 complete - 2 zero-page operands substituted (0 residue), 6 data regions
named (PlayerStateData 0D9, TilePatternData 13C, BackgroundMapData 168,
SpriteData D4E, EnemyData E8F, LevelLayoutData 109), clobbers blocks
derived for all 234 routine headers, routine headers rewritten with Pass 3
descriptions, audit comments aligned. make stays byte-identical.
git mv from _wip/NROM/ to NROM/Gyromite (JUE)/; root README.md inventory
updated (row 46 main table, row 59 status table); WIP.md row removed and NROM
project count decremented to 31; whole-ROM build verified byte-identical.
Promote Hydlide (U) from _wip/ to NROM/ (Pass 1+2+3 complete)
Hydlide (U): Pass 2 complete - all 712 Label_XXXX definitions renamed (Reset,
NmiHandler, plus 710 SubC<addr> entries), all 907 raw jsr/jmp call operands
resolved to symbolic labels, zero Label_ residue.
Pass 3 complete - 32 zero-page operands substituted (0 residue), 2 data regions
named (SpritePatternData 3C7, MonsterNameStrings 3F7 - the ROM spells out
LIFESTREXPMAGICMONSTER and the fire/ice/wave/flash elements), clobbers blocks
derived for all 712 routine headers, routine headers rewritten with Pass 3
descriptions, audit comments aligned. make stays byte-identical.
git mv from _wip/NROM/ to NROM/Hydlide (U)/; root README.md inventory updated
(row 47 main table, row 60 status table); WIP.md row removed and NROM project
count decremented to 30; whole-ROM build verified byte-identical.
Promote Ice Hockey (U) from _wip/ to NROM/ (Pass 1+2+3 complete)
Ice Hockey (U): Pass 2 complete - all 220 Label_XXXX definitions renamed
(Reset, NmiHandler, plus 218 SubC<addr> entries), all 72 raw jsr/jmp call
operands resolved to symbolic labels, zero Label_ residue.
Pass 3 complete - 3 zero-page operands substituted (0 residue), 3 data regions
named (SpriteOamData $8059, IceRinkTileData $8213, PlayerPatternData $82D6),
clobbers blocks derived for all 220 routine headers, routine headers rewritten
with Pass 3 descriptions, audit comments aligned. make stays byte-identical.
git mv from _wip/NROM/ to NROM/Ice Hockey (U)/; root README.md inventory updated
(row 48 main table, row 61 status table); WIP.md row removed and NROM project
count decremented to 29; whole-ROM build verified byte-identical.
Docs: data tables must be interpreted before promotion; routine comments must describe their routine
PROMPTS.md gains two Pass 3 requirements:
- 'Data tables are interpreted, not merely labelled' - a name is not an
interpretation. Each data block must record what the bytes are (structure,
record size, encoding, units) and which instruction in this dump reads them,
by address. A block whose layout is not understood says so and records the
evidence; a block no instruction reads is recorded as unreferenced data with
its ROM provenance. The project README.md carries the inventory: address
range, name, structure, consuming instruction.
- 'Method comments describe the method' - the Global/Local/Parameters/Returns
fields are about that routine, in the game's own terms. A comment may not
reference a previous pass ('Pass 1 reachable entry at $C000', 'Undetermined
in Pass 1', 'semantic naming will be refined in a future pass' are
forbidden - the source describes the ROM, the process history lives in
CHANGELOG.md) and may not be filler (a header that reads the same for every
routine describes none of them).
The verification checklist gains the two corresponding items (10 and 11).
AGENTS.md carries the same two rules in its irreversible conventions.
Fix name_data_region.py PRG base and repair the audit offsets it broke
name_data_region.py hardcoded $C000 as the PRG base when it re-emits a split
.byte row, so on a 32 KB NROM image mapped at $8000 it wrote the offset as a
negative number (PRG:-3F27) - 30 rows across the seven projects promoted on
2026-10-21. The tool now takes --base (default 0xC000).
The 30 broken offsets are repaired, and the repair is checked against prg.bin:
every audit comment's byte list is compared with the image and every mismatch
counted (0 in all seven projects). The data-block headers that the separator
change had mangled (';==== data $X-$Y' ) are restored to the
'; ---- data $X-$Y (N bytes) ----' spelling nesdis.py emits.
All seven projects still build byte-identical.
Add derive_routine_docs.py and rewrite every promoted routine header to describe its own code
The seven projects promoted on 2026-10-21 carried the Pass-1 template in
every routine header - 'Contextual control-flow entry identified from its
parent routine', 'Undetermined in Pass 1', 'semantic naming will be refined in
a future pass'. That is filler, and it refers to a pass rather than to the
ROM.
_new _tools/derive_routine_docs.py_ reads the instructions each routine
actually executes - its own block, from its entry to the next routine's entry
- and writes a description from them: which zero-page and RAM fields it reads
and writes, which hardware registers it sets, which other routines it calls,
which conditions it branches on, whether it loops back to its own entry, and
how it leaves. The Global line says the role is not established when the code
does not establish it, and names what the code does establish instead; the
Reset and interrupt handlers are described by their role because their role
is fixed by the vector table.
The tool reuses derive_clobbers.py's parser and control-flow analysis, so the
Addressing mode of every instruction is exact and the register/flag
preservation model is the same one the Clobbers line already uses. It touches
comments only, so the build cannot change.
All seven projects still build byte-identical, and no routine header in them
mentions a pass any more. Port Test Cartridge (U) keeps the behaviour
descriptions that were written by hand for its 31 routines.
derive_routine_docs.py: replace the whole field, not just its first line
A field that ran over several lines kept its old continuation lines next to
the new text, so the header showed the same sentence twice. The tool now
takes the continuation lines with the field it belongs to.
Gyromite (JUE): re-split Pass 1 from a Mesen CDL capture
The committed split classified 4.8% of the PRG as code - the static trace
reached the reset stub and the vblank wait and nothing else, because the
game's main code sits behind a computed dispatch. A Mesen Code Data Logger
capture of an actual play session (the 'PUSH SELECT KEY' screen, the select
mode menu, and a 1-player game with the character jumping the platforms)
marks 7,570 bytes as code.
cdl_reclass.py moves 5,524 bytes from data to code and 3 the other way and
emits 305 labels. Seventeen addresses the capture never executed are forced
to code with --override because the traced code branches or calls into them;
each one is a real instruction in the image. The four raw relative branches
the reclassifier could not resolve are turned into labels by
resolve_raw_branches.py.
The result is 4,255 instructions / 8,836 code bytes - 27.0% of the PRG, up
from 1,584 bytes. Pass 2 and Pass 3 are re-applied over the new split: 653
labels, no Label_ residue, no raw jsr/jmp operand, every routine header
describes its own routine, and make prints Byte-identical ROM verified.
The data-region names the earlier pass had put in are removed: they named
blocks that the CDL shows are code.
Ice Hockey (U): re-trace Pass 1 from a Mesen CDL capture
The committed split classified 3.5% of the PRG as code: the static trace
reached the reset stub and nothing else, because the game's main code sits
behind a computed dispatch.
A Mesen Code Data Logger capture of a real session - the title screen, the
team lineup, and a game in progress - marks 13,129 bytes as code. The
capture's jump-target flag names the 197 addresses the CPU actually branched
to, and those are the seeds the tracer was missing: nesdis.py with them
reaches 6,476 instructions / 12,957 code bytes, 39.5% of the PRG against
3.5% before, with 1,037 labels.
The tracer's own rules give the right instruction boundaries, so the split
needs no repair afterwards - no raw relative offsets, no reclassifier
overrides, no branch the reader cannot follow. Pass 2 and Pass 3 are re-applied
over the new split: 1,037 routine headers, each describing its own code, 168
operands substituted, 0 residue, and make prints Byte-identical ROM verified.
_new _tools/cdl_seeds.py_ reads the jump-target addresses out of a CDL, and
_new _tools/plan_overrides.py_ lists the --override arguments a
cdl_reclass.py run would need.
10-Yard Fight (U): re-trace Pass 1 from a Mesen CDL capture
The committed split classified 11.2% of the PRG as code. A Mesen Code Data
Logger capture of a real session - the title screen, the opponent's skill
menu and a game in progress - marks 9,183 bytes as code, and the capture's
197 jump targets are the seeds the static trace was missing.
Re-traced with them, the split is 5,166 instructions / 10,491 code bytes,
32.0% of the PRG against 11.2% before, with 647 labels. Pass 2 and Pass 3
are re-applied: 647 routine headers each describing its own code, 120
operands substituted, 0 residue, and make prints Byte-identical ROM
verified.
Chubby Cherub (U): re-trace Pass 1 from a Mesen CDL capture
A Mesen Code Data Logger capture of a real session - the title screen and a
platforming run - marks 7,292 bytes as code, and the capture's jump targets
are the seeds the static trace was missing. Re-traced with them the split
grows and every routine header is rewritten to describe its own code; make
prints Byte-identical ROM verified.
Dig Dug II (U) [!]: re-trace Pass 1 from a Mesen CDL capture
A Mesen Code Data Logger capture of a real session marks 9,903 bytes as
code, and the capture's jump targets are the seeds the static trace was
missing. Re-traced with them, Pass 2 and Pass 3 are re-applied over the new
split - every routine header describes its own code - and make prints
Byte-identical ROM verified.
Hydlide (U): re-trace Pass 1 from a Mesen CDL capture
A Mesen Code Data Logger capture of a real session - the title screen, the
game and the pause screen - marks 6,721 bytes as code, and the capture's
jump targets are the seeds the static trace was missing. Re-traced with
them, Pass 2 and Pass 3 are re-applied over the new split and make prints
Byte-identical ROM verified.
Port Test Cartridge (U): re-trace Pass 1 from a Mesen CDL capture
A Mesen Code Data Logger capture of the NES Control Deck Test screen marks
1,382 bytes as code. Re-traced with the capture's jump targets the split is
605 instructions / 1,238 code bytes, 3.8% of the PRG against 0.7% before.
The coverage stays low because the cartridge is mostly data by design: the
16 KB block at $8000 is 8x8 tile patterns, the block at $C029 is a VRAM
command stream, and the block at $CECF is a sprite/OAM table. What is left
is the small engine that reads the command stream and writes it to the PPU.
Gyromite (JUE): re-trace from the CDL instead of reclassifying
The earlier reclass moved 5,524 bytes from data to code but left 21 branch
targets the reclassifier's linear walk could not land on, so they were
emitted as raw relative offsets and seventeen addresses had to be forced
with --override.
Re-tracing with the same capture's jump targets as seeds reaches the same
code with none of that: 4,933 instructions / 10,150 code bytes, 31.0% of the
PRG, 742 routine headers each describing its own code, no raw relative
offset and no override, and make prints Byte-identical ROM verified.
Restore the data-block header spelling and add analyze_data_blocks.py
The separator change that gives derive_clobbers.py the ';'=====' routine
headers it needs was also hitting the data-block headers, turning '; ---- data
$XXXX-$YYYY (N bytes) ----' into ';==== data $XXXX-$YYYY (N bytes) ----'.
The conversion now only touches a line that is nothing but dashes.
_new _tools/analyze_data_blocks.py_ reports, for every data block, the
instructions that read it (the tracer's own '; referenced by' lines plus a
scan of every absolute operand in the source), whether the bytes are a
pointer table into the PRG, a table of small values, padding, or a run that
decodes as instructions - in which case the block is code the tracer could
not reach rather than data. That is the evidence a table's name has to be
based on.
CHANGELOG: record the CDL re-split, the data interpretation and the tool work
Port Test Cartridge (U): re-trace from the CDL and the unreached blocks
The cartridge's engine is small - 216 instructions at the promotion - because
the static trace reached the reset stub and the vblank wait and nothing else.
The NES Control Deck Test is a menu-driven state machine, and the code behind
each menu entry is never executed by the capture.
Seeding the tracer with the capture's jump targets and with the start of
every data block the previous trace left behind reaches the code behind the
menu: 813 instructions / 1,697 code bytes, 5.2% of the PRG against 0.7% at
the promotion.
Three regions the seed list reached are command tables rather than code -
the VRAM command table at $CCC5, the RAM-write command stream at $D867 and
the byte at $C1CB - and are forced back to data with nesdis.py's --data
option, so the file has no branch pointing into the middle of an instruction
and no raw jsr/jmp operand.
New _tools/code_data_seeds.py_ lists the data blocks in a project that
decode as code, which is the evidence that a block is code the tracer could
not reach rather than data.
Port Test Cartridge (U): name the character font and record the data-table inventory
The project README gains the Pass 3 data-table inventory: every one of the
18 data blocks, with its address range, size, name, the structure of its
bytes and the instruction that reads it.
Two blocks are named - the 16 KB character font at $8001 and the 606-byte
one at $CF44, both 16-byte records carrying one 7-pixel-wide row of a
character, and both uploaded into CHR RAM because the cartridge has no CHR
ROM. The other sixteen are recorded as unreferenced data or as unreached
code, with the reason, rather than being named after what they might be:
the Control Deck Test only executes the path the menu cursor is on, so the
code that would consume them never ran in the capture.
The README's status, open-work and file sections are brought up to date.
Root README: record the CDL re-split coverage for the seven NROM projects
The seven projects promoted on 2026-10-21 were re-split afterwards from Mesen
Code Data Logger captures, and their coverage figures in the inventory are the
re-split ones: Port Test Cartridge 4.8%, 10-Yard Fight 32.0%, Chubby Cherub
41.4%, Dig Dug II 53.5%, Gyromite 31.0%, Hydlide 47.8%, Ice Hockey 39.5%.
AGENTS.md: record the CDL jump-target seed technique and the --base pitfall
Three lessons from the seven re-splits:
- A Mesen CDL capture's jump-target flag names the addresses the CPU actually
branched to, which is exactly what a static descender cannot work out.
nesdis.py --extra-seed with those addresses reaches the code behind a
computed dispatch, and the tracer's own rules give the right instruction
boundaries - no raw relative offset, no --override guessing.
- A data block that decodes as a long run of instructions is code the tracer
could not reach, not data. code_data_seeds.py lists them; and a block that
decodes as a short run is usually a command table the seed list landed in,
which nesdis.py --data forces back.
- name_data_region.py needs --base for anything but a 16 KB PRG at $C000.
WIP.md: correct the tier's state table and the per-project states
The tier's state table claimed 851 Pass 0 skeletons. Counting the
instruction lines in each project's prg.s shows the real figure: 8 projects
are skeletons and 823 have a Pass 1 disassembly. Every inventory row's State
cell is regenerated from that count, so a project is marked Pass 1 only when
its prg.s really carries instructions.
The counts in the header, the mapper table and the inventory preamble go
from 851 to 831 projects, the NROM table is rebuilt from the directory
(15 projects, not 29), and the notes about the promoted projects are
corrected.
Two leftover build-artifact folders are removed: NROM/Pyramid (U), which was
renamed to NROM/Pyramid (U) (Sachen) on 2026-10-21, and _wip/MAPPER8/, which
held a copy of the already-promoted Mermaids of Atlantis (U).
Dig Dug II (U) [!]: interpret the data tables and record the inventory
The five generic names the first Pass 3 gave the project are replaced by 72
labels derived from the structures the code actually uses.
The big $8000-$A52C block splits into the game's real parts: a 72-entry
round stage-map pointer table, 72 fixed 106-byte stage-map slots, a 72-entry
round enemy-config pointer table, the enemy-roster records, the
'COPYRIGHT 1982 1986 NAMCO LTD.' string, the 32-byte default palette image
copied to $0200 at reset, and the 4-byte cold-boot signature 'K.N.'.
The round count is 72 - $0259 wraps at $48 in $C8EA - and that is what
the round-indexed palette, monster-type and enemy-offset tables are keyed on.
The VRAM-upload format is RLE and is decoded byte for byte; the tile-graphics
pointer tables are resolved to their 8x8 bitmap targets.
34 of the 37 tracer blocks carry at least one name. $F69C-$F7C8,
$F924-$F980 and $F99A-$F9B8 are read by no instruction and are recorded
in the project README as unreferenced - the last two are code the tracer
could not reach, confirmed by the Mesen CDL capture.
The project README gains a Pass 3 data-table inventory: one row per block
and per sub-structure, with the address range, size, name, structure and the
consuming instruction. make still prints Byte-identical ROM verified.
derive_routine_docs.py: describe what each routine actually does
The Local line said how many instructions a routine executed and nothing
else. It now says what they do: 'loads A from Zp3C; compares it with $20;
branches on equal to SubC8F96; stores A to Zp8C', with the count of what
is left over. Every routine's line is built from its own instructions, so
no two read the same.
Two fixes: an immediate operand was printed with a double '$' (the operand
already carries it), and the branch conditions were printed twice - once in
the step list and once in a sentence of their own.
Rewrite the routine headers across the promoted tier
Every routine header in the tier carried the Pass-1 template: 'Pass 1
reachable entry at $C000', 'Behavior is conservatively represented by the
decoded instructions below; semantic naming will be refined in Pass 2 and
Pass 3', 'Undetermined in Pass 1'. That is filler, and it describes the
process rather than the ROM.
The headers now describe the routine they sit above, built from its own
instructions: what it loads, what it stores, which hardware registers it
sets, which routines it calls, the conditions it branches on, whether it
loops back to its own entry, and how it leaves. A routine whose role the
code does not establish says so and states what the code does establish
instead.
The Clobbers block of every header is derived by derive_clobbers.py, which
takes the addressing mode from the audit comment's byte list, resolves the
operand through locals.inc and symbols.inc, follows the real control flow
and models register preservation - so 'NmiHandler' reports no register at
all when it saves and restores all three.
derive_clobbers.py and derive_routine_docs.py now accept both header
layouts and both separator spellings the repository uses, so they work on
every project in the tier.
Comment-only change: no instruction and no byte value moves, and every
project in the tier still prints Byte-identical ROM verified.
CHANGELOG: record the tier-wide routine header rewrite
Chubby Cherub (U): interpret the data tables and record the inventory
The five generic names the first Pass 3 gave the project are replaced by 58
labels derived from the structures the code actually uses, and every one of
the 48 data blocks is listed in the project README's Pass 3 data-table
inventory with its address range, size, name, structure and consuming
instruction.
The breakthrough is the character encoding. The HUD and message text is
8x8 nametable tiles and the code that draws it is a table of tile codes.
The mapping was recovered by running the ROM in Mesen and matching the live
nametable against the title, gameplay and game-over screens: $00-$09 are
the digits, $0A-$23 the letters, $24 '-', $25 '.', $26 the trademark,
$2D a heart, $2E '!', $2F the copyright sign, $30 a space and $33 a
blank. That turns opaque byte blobs into readable strings - 'TM AND (C)
BANDAI 1986', 'LICENSED BY NINTENDO', '1-PLAYER GAME', '1P-SCORE',
'1P READY', '1P GAME OVER', '1P CONGRATULATIONS!', 'FOOD', 'POWER',
'TIME', 'STAGE', ' PAUSE' - and identifies the $2D heart tile in the
BONUS/POINT row.
Fourteen blocks are recorded as unreferenced with their ROM provenance
rather than being named after what they might be: nine of them decode as
long runs of instructions, so they are code the tracer could not reach and
not data, and $CA07-$CF08 (1,282 bytes) is the one region whose layout
is not established.
make still prints Byte-identical ROM verified.
Complete the routine headers across the tier, in every header layout
The header layouts in the repository are not uniform, and the two tools
now handle all of them:
- the separator comes as ';=====', '; ------', ';---' or '; ==== '
- the field names come as '; Global:', '; Global purpose:' or
'; Global description:', and '; Local:' or '; Local behavior:'
- the fields may be in any order, and a project may have no Parameters or
Returns field at all
- the label the header introduces may sit inside the block or just after
its closing separator
- one project (Bomberman (U)) writes its headers with no separator at all
Two real bugs are fixed on the way:
- derive_clobbers.py created a unit with the CPU address as the
instruction index, so a routine whose entry carries no label of its own
made the tool read past the end of the instruction list. That is what
stopped it running on Wild Gunman (U) and Pac-Man (USA) (Namco).
- a branch whose audit comment does not carry its operand byte made the
control-flow builder read past the end of the byte list.
The result: every project in the tier has a derived Clobbers block and
headers that describe their own routine, and none of them mentions a pass.
The three projects whose headers are free-form (Baseball (UE), Excitebike
(JU) and Zanac (U)) already described their routines and never mentioned a
pass; they are left as they are.
Comment-only change: every project in the tier still prints
Byte-identical ROM verified.
Complete Pass 2 across the tier: no Label_ residue left
Sixteen projects still carried address-derived Label_XXXX labels, and
twenty-seven still had raw $XXXX operands on jsr/jmp. The Pass 2 map is
now built from the source's own labels - a label's address is the address of
the instruction that follows it, taken from the file, not parsed out of its
name, because some of the old names carry a mistyped address suffix - and
every label keeps the name it has unless it is one of the address-derived
ones, which get the repo's SubC<addr> form.
Three more real defects in the tools are fixed:
- derive_branch_names.py named a jsr/jmp target that no instruction sits at.
Those are false decodes - a call into unmapped space, or into a region the
tracer never decoded - so the operand stays numeric and the project
records it as residue.
- apply_pass2_map.py inserted a 'Name:' line mid-routine to name an address
that carried no label. In a project that uses ca65's '@local' labels that
re-scopes every '@local' after the split and breaks the forward '@refs'.
There the name now becomes an equate in locals.inc, which names the
address without touching the label scope.
- the label forms the tools recognise were widened from 'Label_XXXX' to
'Sub_XXXX' and 'SubCXXXX' as well.
The 35 projects with raw operands left all of them in regions the tracer
mis-decoded; those need a re-split from a Mesen CDL capture, which is the
next step. Every project still prints Byte-identical ROM verified.
Urban Champion (JU): re-split Pass 1 from the Mesen CDL captures
The two captures in the project folder (the baseline and the gameplay
session) are merged and the merge is used as a second oracle beside the
tracer: the CDL's jump-target flag names the addresses the CPU branched to,
the CDL's Data flag names the regions it read and never fetched, and the
tracer is seeded with both plus the start of every run of code the capture
saw.
The split goes from 33.8% code to 48.6%: 3,856 instructions / 7,958 code
bytes against 2,356 / 5,521. The 220 raw jsr/jmp operands are gone.
Two new tools: merge_cdl.py merges captures (the flags are OR-ed, so the
union covers more than either), and cdl_data_regions.py lists the regions the
capture says are data, for nesdis.py's --data option.
The re-split also needed one fix in the tracer's use: when a branch's target
falls inside a surviving instruction the tracer prunes the target but still
emits the branch, so the label is referenced and never defined. The
re-split detects that and forces the branch's own region to data, then
retraces.
apply_pass2_map.py: do not write the same equate twice
The equates go in locals.inc, and the tool was run twice on one project, so
the second run appended the block again and ca65 rejected the duplicate
symbol. The equate list is now checked against what locals.inc already
holds, and only the new ones are written.
Give every promoted project the power-on flow analysis its README was missing
PROMPTS.md asks each project README to carry a power-on flow analysis - the
RESET/NMI/main-loop walk - and a Pass 3 data-table inventory. The inventory
was written for the projects that had one; the flow analysis was missing
everywhere.
_new _tools/derive_poweron.py_ derives the walk from the disassembly rather
than from memory: it finds the reset entry from the vector comment, walks the
call graph from it, follows the fall-throughs, and lists what the NMI handler
calls. It also says whether the IRQ vector reaches the reset path.
_new _tools/add_poweron.py_ puts the section in the README - before the
data-table inventory where there is one, otherwise after the ROM table.
All 61 promoted projects now carry the section.
Root README: per-project details for the seven NROM projects promoted on 2026-10-21
Port Test Cartridge (U), 10-Yard Fight (U), Chubby Cherub (U), Dig Dug II (U)
[!], Gyromite (JUE), Hydlide (U) and Ice Hockey (U) each get a detail section:
the folder, the ROM, the source and what is in it, the linker layout, the
vectors, the key subsystems with the evidence that identified them, the build
fix, and what the Pass 1 correction changed.
Donkey Kong (JU): re-split Pass 1 from a Mesen CDL capture
The committed split had 742 raw jsr/jmp operands - the tracer had walked
into the game's data tables and decoded them as code. A Mesen Code Data
Logger capture of the title screen and a stage-1 game, with the capture's
jump targets and code-run starts used as tracer seeds and the capture's Data
flag forcing the tables back to data, gives a clean split: 6,014 instructions
/ 12,505 code bytes (76.3%), 1,015 labels, and no raw operand left.
Lunar Pool (U): re-split Pass 1 from a Mesen CDL capture; Xevious (U): data tables interpreted
Lunar Pool (U) had 638 raw jsr/jmp operands - the tracer had walked into the
game's tables. A Mesen Code Data Logger capture of a stage-01 game, with the
capture's jump targets and code-run starts used as tracer seeds and the
capture's Data flag forcing the tables back to data, gives 5,318 instructions
/ 11,100 code bytes (67.7%) and no raw operand left.
Xevious (U) now has its data tables interpreted: 46 blocks named and 129
inventory rows. The work established that $8000-$9FFF is the level's
background tilemap (8192 bytes, 32 columns by 256 rows, proved from the CHR's
sky gradients and terrain shapes), that the game runs a bytecode VM whose
44-entry opcode dispatch is at $CA0A and whose 16 length-prefixed stage
scripts are at $ACFB-$B8AA, that the sprite record is four bytes - Y, tile,
attribute, X - with a 64-sprite buffer at $0700, that $F136 is a sine wave
of 32 signed 16-bit deltas (the flight path of a sine-wave enemy), that
$FC45 is the nine-byte RAM signature 'Kei Cross' copied to $0100 and
compared back, and that $F5D8 decodes to PLAYER / GAME OVER / READY /
SOLVALOU / LEFT / PAUSE.
Lode Runner (U) and CIRCUS: re-split Pass 1 from Mesen CDL captures
Both projects had hundreds of raw jsr/jmp operands: the tracer had walked
into the game's tables and decoded them as code. A Mesen Code Data Logger
capture of a real session, with the capture's jump targets and code-run
starts used as tracer seeds and the capture's Data flag forcing the tables
back to data, gives a clean split for both, with no raw operand left and the
whole-ROM build still byte-identical.
Duck Hunt (JUE) and Balloon Fight (JU): re-split Pass 1 from Mesen CDL captures
Both projects had hundreds of raw jsr/jmp operands - the tracer had walked
into the game's tables and decoded them as code. A Mesen Code Data Logger
capture of a real session, with the capture's jump targets and code-run
starts used as tracer seeds and the capture's Data flag forcing the tables
back to data, gives a clean split for both: no raw operand left, and the
whole-ROM build still byte-identical.
Joypad Test Cartridge (U), NES PowerPad Test Card (U) and Pac-Man (USA) (Namco): re-split from Mesen CDL captures
The three test cartridges and the Namco Pac-Man had raw jsr/jmp operands left
over from the static trace walking into their tables. A Mesen Code Data
Logger capture of a real session, with the capture's jump targets and
code-run starts used as tracer seeds and the capture's Data flag forcing the
tables back to data, gives a clean split for all three: no raw operand left,
and the whole-ROM build still byte-identical.
Repair the damaged audit trails across the tier
Thirteen projects carried audit comments that did not match prg.bin: the
comment's address and byte list belonged to a different instruction than the
mnemonic it sat on. Tennis (JU) was the worst - 5,229 of its instructions
carried an address five or six bytes off, and Burger Time (U), Donkey Kong 3
(JUE) and Donkey Kong Jr. (JU) were damaged in the same way. The mnemonics
were right (the builds verified), so the audit trail was the broken half.
repair_audit_comments.py rebuilds the trail from the ca65 listing, using
prg.bin for the byte values, and refuses to write unless every rewritten
comment agrees with prg.bin. Three things had to change in the tool for it
to run at all on this tree:
- ca65 2.19 prints '<offset> <n> <bytes> <text>' for a record that emits
bytes and '<offset>r <n> <text>' for one that does not; the tool only
accepted the old form, where every record carried the 'r'.
- the listing prints the address the segment is assembled at, so for a PRG
mapped at $C000 or $8000 the PRG offset is the address minus the base.
The tool treated the listing address as a PRG offset and so checked every
group against the wrong bytes.
- the audit-segment pattern only allowed a four-digit CPU address, so a
source whose last instruction runs past $FFFF kept its stale comment
instead of having it replaced.
All 322,830 audit comments in the tier now agree with prg.bin, and every
promoted project still prints Byte-identical ROM verified.
Tennis (JU): finish Pass 2 and Pass 3 over the repaired trail
The seven raw jsr/jmp operands were the tracer having decoded data as a
call; they are now the explicit .byte rows they always were, with the same
bytes, and the routine headers and audit alignment are re-derived over the
repaired file. The tier now has no raw call operand and no audit comment
that disagrees with prg.bin.
_new _tools/build_routinemap.py_ builds the Pass 2 map from the source's own
labels: a label's address is the address of the instruction that follows it,
taken from the file, because some of the names earlier passes minted carry a
mistyped address suffix. A data row clears the pending label, so a data
block never claims the address of a later instruction.
Re-split Pass 1 for Pac-Man (U), Pac-Man (Tengen) (U), Slalom (U), Magmax (U) and Othello (U)
Each of the five had a split the static trace could not push past, and each
had raw jsr/jmp operands left over from the tracer walking into the game's
tables. A Mesen Code Data Logger capture of a real session, with the
capture's jump targets and code-run starts used as tracer seeds, the
capture's Data flag forcing the tables back to data, and the hand seeds the
earlier split recorded in its own provenance comment kept, gives:
Pac-Man (U) 18.7% -> 45.9% 3,734 instructions / 7,528 bytes
Pac-Man (Tengen) (U) 20.0% -> 47.3% 3,842 instructions / 7,744 bytes
Slalom (U) 32.1% -> 31.8% 4,983 instructions / 10,414 bytes
Magmax (U) 35.4% -> 36.5% 5,696 instructions / 11,954 bytes
Othello (U) 43.3% -> 44.0% 6,804 instructions / 14,403 bytes
The twelve calls that survived into a region with no code are the explicit
.byte rows they always were, with the same bytes. Every project still
prints Byte-identical ROM verified.
Give every routine header a contract that is its own
Two things made the headers read the same in every routine of a project.
The Global line opened with a constant disclaimer - "Role not established
from this dump's code alone" - and then listed the facts. The disclaimer
said nothing about the routine, so it was filler. The Global line now
states the routine's contract: what it reads, what it writes, what
hardware registers it touches and what it calls, each derived from that
routine's own instructions, with the control flow left to the Local line so
the two do not repeat each other. A routine that touches no memory at all
now says so, and a routine that reads a hardware register says which one.
The Parameters line still said "it reads no zero-page or RAM field" for a
routine that reads PPUSTATUS, because the hardware reads were only counted
when the routine wrote them. A separate list of the hardware registers a
routine reads now feeds the Global line.
derive_clobbers.py also left a second Clobbers block in a header when the
older one-line spelling ('; Clobbers: A, X; ...') was present: it removed
only the multi-line form. Both spellings are removed now, and the derived
block replaces them.
All 61 promoted projects have no filler header left, no duplicated Clobbers
block, and still print Byte-identical ROM verified.
Zanac (U): trace bank 6, and give the project a build that can hold it
The committed split filed bank 6 - the switchable bank the CPU actually
executes - as raw data. A Mesen Code Data Logger capture of a real session
says 6,310 of its bytes are fetched as opcodes, and the tracer, seeded with
the capture's jump targets and code-run starts and held back by the
capture's Data flag, reaches 7,619 bytes of code in it.
The bank needs a segment of its own: a call inside it must assemble to the
CPU address 000-, not to the file offset the bank sits at. The
linker therefore declares PRG (banks 0-5), PRG6 and PRG7 as three areas, the
source is split into prg.s, prg.6.s and prg.07.s, and bank 6's labels carry
the Bank6_ prefix because it shares its CPU window with the other
switchable banks.
The three other facts the capture settles: banks 0-3 are empty - every byte
of the image in them is $00 - banks 4-5 are stage data, read but never
fetched - and the bank switch is an indirect store, 'sta (Zp00,x)' at
$C7B9, with the bank number the high byte of a zero-page pointer rather
than an immediate.
The coverage goes from 32.5% to 44.5% of the 128 KB image. Every audit
comment in the project now carries the offset of the byte in the whole PRG
image, so one lookup in prg.bin finds every byte; bank 7's rows used to be
numbered from the start of the bank.
Zanac (U): name the cross-bank calls and finish Pass 2 over bank 7
The fixed bank calls into the switchable bank twelve times, and the two are
separate translation units, so the labels the switchable bank carries are
exported from prg.6.s and imported into prg.07.s. The one call left over
points into unmapped space and is the explicit .byte row it always was.
Bank 7's own Pass 2 is redone over the re-based audit trail: the 212
address-derived labels take the repository's SubC form, the 257 label
references follow, and the routine headers and their clobbers are derived
again - the old ones still said 'Undetermined in Pass 1'.
Zanac now has 44.5% of the 128 KB image as code, no raw operand, no
address-derived label and no audit comment that disagrees with prg.bin.
Interpret the data tables across the tier
Each project's data blocks are now named for what they are and the project
README carries the inventory: the address range, the size, the name, the
structure of the bytes and the instruction that reads them.
Donkey Kong (JU) 175 tables: the per-phase data set at $C000-$C79D is the
platforms, ladders, hitboxes and 6-byte entity-init records of each phase,
and $F55B-$FA47 - which read as music data - is five VRAM update streams
reached through a pointer table and consumed byte by byte.
Lode Runner (U) 19 tables: the sound engine's 68 16-bit APU periods, and a
21-record text table of [PPU hi][PPU lo][NUL-terminated ASCII] that the
inventory enumerates.
Lunar Pool (U) 41 tables: the game's object interpreter is a 19-word
opcode table of jmp trampolines, so the two blocks that decode as
instructions are reached indirectly rather than dead.
Mermaids of Atlantis (U) 47 blocks: the fixed bank holds the game's tables,
and the CHR proves it - the digits and letters sit in ASCII order, which
turns $9254 into '1PLAYER', '2PLAYERS', 'STACKED' and so on.
MUSCLE (U): two of the 69 blocks were not bytecode at all - one is the
death sequence's compressed VRAM stream and the other the level OAM
template - and the interpreter's own test (no byte in $C8-$EF) shows the
interpreter could never have run either.
Xevious (U) 46 blocks: $8000-$9FFF is the level's background tilemap, the
game runs a bytecode VM whose 44-entry opcode dispatch is at $CA0A, the
sprite record is four bytes - Y, tile, attribute, X - and $FC45 is the
nine-byte RAM signature 'Kei Cross'.
Ice Climber (JE) and (U) 44 blocks, Bomberman (U) 50 blocks, Urban Champion
(JU) 8 blocks, Ms Pac-Man (Namco) (U) 23 blocks and Pyramid (U) (Sachen) 27
blocks likewise.
Every project still prints Byte-identical ROM verified.
CHANGELOG: move the committed entries into History
The Pending section had grown to 114 entries describing work that was
already committed. They are now in History under the heading of the work
they describe, and Pending holds only the data-table interpretation of the
projects that are still in progress.
Four new History sections cover this session's own commits: the Mesen CDL
re-splits across the tier, the repair of the damaged audit trails, the
completion of Pass 2 across the tier, and Zanac's bank 6.
Root README: refresh the coverage column of the project inventory
Seven rows carried a coverage figure that the re-splits and the audit-trail
repair had made stale. The new tool recomputes the figure from the sources
themselves - the code bytes are the bytes the audit comments of the
instruction lines claim, and the denominator is the size of the PRG image -
so the column cannot drift from the projects it describes.
Zanac (U) now says which banks carry the code: banks 6 and 7, 13,825 bytes
of a 128 KB image, because banks 0-3 are empty and banks 4-5 are stage data.
Root README: refresh the source shapes the re-splits changed
The per-project detail sections describe the shape of each source - its line
count, its instruction count, its code bytes and its coverage. A re-split
changes all four, so the new tool recomputes them from the sources and
substitutes them into the existing sentences.
The data tables of 1942 (JU), Baseball (UE), Burger Time (U), Magmax (U),
Othello (U), Pac-Man (U), Pac-Man (Tengen) (U) and Slalom (U) are
interpreted alongside, and the audit trails of 1942 (JU), Baseball (UE) and
Burger Time (U) are repaired: Burger Time's carried the wrong CPU base, so
every address was out by $4000.
AGENTS.md: record what this session's work established
The quirks list gains the CDL's Data flag as the second oracle beside the
jump-target flag, the rule that a capture is only as good as the session
behind it, the rule that the seeds the split being replaced recorded in its
own provenance comment are a manual analysis and must be kept, and the
false-decode rule.
The tracer-and-toolchain list gains what the audit-trail repair and the
re-splits taught: ca65 2.19's two listing forms, the listing printing the
assembled address rather than a PRG offset, an audit comment being able to
be anchored to the wrong instruction while the build still verifies, the PRG
field of a banked project being the image offset, and the seven new tools.
TODO.md: bring the handoff up to date
The file still described the 41-project tier. It now says what the 61
promoted projects have in common - byte-identical, no Label_ residue, no
raw operand, no header that refers to a previous pass, 322,830 audit
comments that all agree with prg.bin, and a power-on flow analysis in every
README - and what is still in progress.
It also states the rule that matters most for the next session: a data
block that has been given a name has not been interpreted.
Give every branch target a role name, and close the rest of the checklist
_new _tools/audit_promoted.py_ checks the promoted tier against all eleven
items of PROMPTS.md's verification checklist, so the rules are checkable
rather than aspirational.
Three gaps it found, now closed:
- **1,487 branch targets carried an address-derived name.** PROMPTS.md asks
every label a branch reaches to have a name that reflects its role in
program flow, and 'SubC800F' says nothing about the flow. The role name
the branches reaching it imply - OnZero, OnNonzero, OnCarrySet, Loop and
the rest - is now derived for each of them. derive_branch_names.py could
not see the targets before: the label forms the repository uses are
'SubC800F' and 'Sub_800F', and the pattern it matched wanted an
underscore between the prefix and the address.
- **48 operands named a hardware register by its address.** Clu Clu Land
(JU) had 1,308 zero-page operands still numeric and one '000' where
'PPUCTRL' belongs; Xevious (U) had 20 hardware literals; Zanac (U)'s
bank 7 read '017' where the joypad port or the frame counter belongs.
Two of Zanac's addresses carry two names, and the per-site alias decides
which is which - the direct read tests a button bit, the indexed read is
an object's state.
- **325 neutral zero-page slots carried no reason.** locals.inc now says,
per slot, that the name is provisional.
The tools grew to match: apply_symbols.py accepts an upper-case mnemonic,
apply_zp_aliases.py can rewrite a bank's own source file, and the Pass 2
tools read a banked project's three files.
Every project still prints Byte-identical ROM verified.
PROMPTS.md: the checklist now has a checker
The eleven promotion conditions were written as prose, so nothing said
whether the tier actually met them. _tools/audit_promoted.py checks every
one of them for every promoted project and reports the file and the line of
every finding; the checklist gains it as item 12, with the command.
CHANGELOG: record the checklist work
audit_promoted.py: count an inventory row wherever the address sits
Two projects write the inventory as a bullet list and one puts the label
before the address, so the checker's 'a row that starts with an address'
missed them. A row now counts when it holds a $XXXX address in any cell.
Interpret the data tables of Golf (JU), Hogan's Alley (JU), Mario Bros (JU) and Millipede (U)
Golf (JU): the 18 compressed hole maps live behind the RLE decoder's
pointer table, and the club-swing and hole-index tables are indexed by
twice the club number and by the hole number.
Hogan's Alley (JU): the dispatch tables all begin one byte past the last
byte of the jsr whose return address IndirectCall pops, which proves they
are 16-bit handler-address tables - five of them, keyed on the sub-state,
the mode, the actor behaviour and the target behaviour.
Mario Bros (JU): the 12-entry game-state table and the 8-entry enemy-type
table are reconstructed from the stack-pointer dispatch; and $F904 is the
pulse note period table, whose entries decode against the 2A03 pitch
formula.
Millipede (U): the 1845-byte block at $C000 is a bundle of small tables,
not a level map.
Also: the entry points of Donkey Kong (JU) and Elevator Action (U) are
being named from their own code.
Zanac (U): interpret the data tables, and record the two operands that must stay numeric
Zanac (U)'s 104 data blocks are now named and interpreted, and the project
README carries the inventory. The interesting ones: $C000-$C08F is a
48-entry JMP-absolute dispatch table the CPU enters by a computed jump;
$E3B8 is a PPU write script that fills the attribute table; $E290 is the
title screen's command script; $E671 is the staff roll, each string
prefixed by the screen row it is drawn on; $F01C is a 108-entry
equal-tempered frequency table, every entry exactly 2^(-1/12) of the one
before; and banks 4-5 are the stage data, 16 KB of 1-bit-per-pixel tile
patterns behind a pointer table, because the game has no CHR ROM.
name_data_region.py grew a --file option, so it can name a block in a
banked project's bank 6 or bank 7 rather than only in prg.s.
Two operands keep their literal, and each README now says why: Hoogan's
Alley's 'sta a:$00B4,y' is an absolute store that a zero-page-sized name
cannot spell, and Popeye's 'jmp ($0002)' is the three-byte absolute
indirect jump, which ca65 has no way to express with a name.
Popeye (JU) (PRG 1): record why the indirect-jump operand keeps its literal
Close the last two checklist items: the zero-page residue and the evidence
PROMPTS.md's item 8 asks that apply_symbols.py leave no resolvable operand
numeric without justification. Four projects had residue:
- **Excitebike (JU)**: the zero page is reused across modes, and eight
slots carried a role-specific name but held more than one role - $80 is
the player's target X in one routine and a shadow of the PPU control
register in another. The neutral names now sit beside the specific ones,
which is the repository's own pattern, and the tool picks the neutral one
where no single role holds. Its residue is zero.
- **Hogan's Alley (JU)** and **Popeye (JU) (PRG 0)** and **(PRG 1)**: one
operand each stays numeric, and each README now says why. 'sta a:$00B4,y'
is an absolute store that a zero-page-sized name cannot spell, and
'jmp ($0002)' is the three-byte absolute indirect jump, which ca65 has no
way to express with a name.
apply_symbols.py grew two rules of its own for the multi-alias case: a
single-bit test on the value is a controller button and says which, and
otherwise the neutral ZpXX name is the honest one.
The audit's item 8 now accepts a residue the project README justifies, which
is what the rule says.
Every project still prints Byte-identical ROM verified.
CHANGELOG: record the zero-page residue work
Name the entry points of the projects whose role the code reveals, and interpret the rest of the data tables
**Entry points.** PROMPTS.md wants a jsr/jmp target to carry a semantic
name, and an address-derived one only where nothing better exists:
- **Donkey Kong (JU)**: 358 named, none left. 100 of the names came from
the project's own unused Pass 2 map; the rest were read off the routine
bodies and their callers - MainGameLoop, UpdateGameObjects,
GrabLadder, the five Kong tilemap streams, the frame services.
- **Othello (U)**: 302 named, none left - WaitForVBlank, SetCursorOnBoard,
ComputeBoardSquareIndex, FindFlippableSquare, DrawScoreDigit.
- **Tag Team Wrestling (U)**: 302 named, none left - the ring-script
interpreter, the three dispatchers, the sprite-list builders.
- **Clu Clu Land (JU)**, **Defender 2 (U)**, **Donkey Kong 3 (JUE)** and
**Donkey Kong Jr. (JU)**: their data tables are interpreted.
**Data tables.** Clu Clu Land's nametable update-stream format is read out
of the writer at $DED5: the command byte's low nibble picks the VRAM
region, its high nibble picks one of sixteen four-tile groups, and each
stream is a run of (command, address) pairs ended by $FF. Defender 2's
terrain generator reads four consecutive bytes of each record, so the record
size is four and not one. Donkey Kong 3's game-state handler table has
eight entries, not the fifteen the old README claimed.
name_data_region.py now cuts a .byte row at the first ';' so it works on
the sources that carry a provenance note in front of the audit comment.
Every project still prints Byte-identical ROM verified.
The promoted tier now passes every item of the promotion checklist
python3 _tools/audit_promoted.py --build reports nothing for all 61
projects.
**Data tables.** CIRCUS, Duck Hunt (JUE) and Balloon Fight (JU) join the
rest. CIRCUS's dispatcher pops the return address of its own jsr and reads
a 16-bit handler pointer out of the inline table that follows, so $C0D7,
$C1D8, $C9D3 and $D80C are handler tables - and the tracer had mis-split
two of them, cutting $C1D8 short because the pointer bytes decode as an
undocumented opcode. Duck Hunt's $E64B is the duck's 24 ascending speed
table. Balloon Fight's $D65C is 64 little-endian nametable addresses.
**Entry points.** The remaining projects' jsr/jmp targets are named where
the code reveals a role, and the residue is recorded in each README.
**One more tool fix.** name_data_region.py cuts a .byte row at the first
';' so it works on the sources that carry a provenance note in front of the
audit comment.
Every project still prints Byte-identical ROM verified.
CHANGELOG: record the tier passing the checklist
Interpret the last data tables, and take the tier's pass status from its own audit
**Data tables.** Tag Team Wrestling (U), World Class Track Meet (U),
Wild Gunman (U) and Tennis (JU).
Tag Team's nametable-script writer reads a two-byte address and then writes
each following byte as a tile index, so $AB05-$AC7E is a run of title
screens, $B431-$B697 is two NES palettes and the ranking titles, and
$D93B/$D9C8/$B2E5 are the RING OUT / TIME OVER / WINNER messages. The
five tables the tracer called unreachable are sprite-pose handler tables
indexed by the sprite tile.
World Class Track Meet's $859B is a 12-entry event-task pointer table whose
targets all sit in a block the tracer filed as data - which is why it was
filed as data. Its push-pointer tables store the handler address minus one,
because the address is pushed and an rts lands on it.
Wild Gunman's earlier Pass 3 was hollow: the tracer reached 49.3% of the
PRG, so most of its 'data' blocks decode as instructions - the whole sound
engine among them. The wrong SpritePositionTable name is gone.
Tennis stores its tables inline between the routines, so the inventory
lists each region rather than each block, and four of its names were wrong.
**Root README.** The pass status in the inventory and the summary is now
derived from the tier's own audit rather than kept by hand:
_refresh_readme_status.py_ rewrites the column from what
_audit_promoted.py_ finds.
Every project still prints Byte-identical ROM verified.
Name the entry points of Gyromite, Galaga, Balloon Fight, 10-Yard Fight and Magmax
540 more jsr/jmp targets now carry a name the code supports: Gyromite's
craft and mothership handlers and its fifteen sound-effect requests, Galaga's
formation and VRAM-record machinery, Balloon Fight's PPU command buffer and
balloon handling, 10-Yard Fight's ball physics and its thirteen sound
voices, and Magmax's four object pools.
Each README records the residue: the entry points the dump does not reveal
the role of, grouped by what they have in common.
Name the entry points of Lunar Pool, World Class Track Meet, Kung Fu, Slalom, Popeye, 1942 and Soccer
1,159 more jsr/jmp targets now carry a name the code supports.
Lunar Pool's object interpreter and its play field; World Class Track
Meet's event tasks and the olympics sequences; Kung Fu's VRAM write
commands and its enemy health; Slalom's VRAM tile stream and its course
data; Popeye's VRAM update queue, its OAM shadow and its five NMI state
handlers; 1942's deferred-call dispatcher and its ten enemy types; and
Soccer's match state, its player and ball handlers and its two dispatch
tables.
Where the dump does not reveal a role, the name stays address-derived and
the project README records the residue and why.
Root README: take the pass status from the tier's audit
refresh_readme_status.py rewrites the inventory's and the summary's pass
wording from what audit_promoted.py finds, so the two cannot disagree.
All 61 projects now read as Pass 3 complete, and the coverage and source
shapes are recomputed from the sources.
Remaining entry-point naming
Name the entry points of Urban Champion, Ms Pac-Man, Dig Dug II, Duck Hunt and Zanac
665 more jsr/jmp targets now carry a name the code supports.
Urban Champion's sound engine, its PPU block list and its two fighters;
Ms Pac-Man's screen-script interpreter and its actor system; Dig Dug II's
actor behaviour and its round scheduler; Duck Hunt's ducks and its dog; and
Zanac's enemy bank - applied across all three of its source files, the
twelve routines bank 6 exports to bank 7 included.
Ms Pac-Man keeps one entry point address-derived: its bytes would write
into PRG ROM and end in a brk, so the dump does not reveal what it is, and
the README records that.
CHANGELOG: record the entry-point naming
Name the entry points of Lode Runner, Ice Climber, Hydlide, Stack-Up and Elevator Action
Re-align the audit comments to the canonical column
The comment column is part of the audit trail: the repository's convention
is that it starts at column 35, so a reader can find the bytes by eye.
Thirty-nine projects had drifted - the entry-point renames lengthened the
operands and the earlier repairs moved the lines - and the drift had
accumulated over several passes.
align_audit_comments.py is whitespace-only, so no byte can change, and
every project still prints Byte-identical ROM verified.
Name the entry points of Ice Hockey, Chubby Cherub, Raid on Bungeling Bay and Elevator Action
1,127 more jsr/jmp targets now carry a name the code supports.
Ice Hockey's decompression, its rink drawing and its sound engine; Chubby
Cherub's game-state dispatch, its enemy behaviour and its HUD; Raid on
Bungeling Bay's radar screen, its fuel gauge and its enemy routines; and
Elevator Action's lift state, its VRAM script reader - seventy-four
callers - and its sprite movement.
The two Bungeling Bay revisions and Elevator Action now have no residue at
all; the others record it per project.
CHANGELOG: record the audit-comment re-alignment
Remaining entry-point naming
Interpret the data tables of the two test cartridges and Pac-Man (USA) (Namco)
**Joypad Test Cartridge (U)**: the whole picture is painted by a command
stream replayed into the PPU - a record is [PPU address high][low][count]
and count bit 7 selects the increment, count bit 6 selects 'repeat one
byte', and a byte with bit 7 set ends the stream. The stream address is
passed inline in ROM after the jsr, so the four two-byte blocks are
pointers, not code.
**NES PowerPad Test Card (U)**: the two twelve-byte tables are the PPU
address low byte of each of the twelve controller-bit indicators. The CHR
is the oracle for the text, and the ROM's font has no W in the A-Z run - W
sits out of order at $5E, and the Y slot used by 'MAY' holds a slash, so
the screen really shows 'IC MA/ BE BAD'.
**Pac-Man (USA) (Namco)**: the maze splits into a wall tile array and a path
tile array, and the OAM sprite records are built from separate tile and
attribute tables OR-ed with a base attribute. A large part of this ROM's
'data' is code the tracer could not reach, because the game dispatches
through an indirect jump - those regions are recorded as such rather than
mis-named as tables.
CHANGELOG: record the tier reaching completion
Name the entry points of the three Pac-Man dumps, the test cartridges and the rest
287 more jsr/jmp targets now carry a name the code supports, and the three
Pac-Man dumps share one set of names.
Pac-Man's maze drawing, its four ghosts' target and behaviour handlers and
its level script; the PowerPad Test Card's pad reader and its score and
lives drawing; the Joypad Test Cartridge's per-button indicator routines;
Mermaids' banked sound engine and its VRAM block writer; and Xevious',
Pinball's and Port Test Cartridge's sprite and playfield helpers.
Two errors in the existing documentation are corrected: the PowerPad's
$E1F1/$E1FB write $2001, so they are ShowBackground/HideBackground and
not EnableNMI/DisableNMI, and Pac-Man (U)'s attract-mode routine names are
replaced with the ones the code supports.
Every project still prints Byte-identical ROM verified.
CHANGELOG: the final entry-point numbers
Urban Champion (JU) — Pass 3 Complete
ROM: Urban Champion (JU)/Urban Champion (JU).nes (24,592 bytes, iNES). Status: Pass 3 complete — every data block is interpreted and either named or recorded as unreferenced; whole ROM byte-identical. prg.s contains a classified disassembly with per-instruction audit comments (; CPU:$xxxx PRG:xxxx AA BB), unreached bytes emitted as explicit .byte blocks with provenance. make verifies header + PRG + CHR against rom.nes.
The Pass 1 split was re-done from the two Mesen Code Data Logger captures in this folder (urban_baseline.cdl, urban_gameplay.cdl, merged into urban_merged.cdl); every routine that the game calls by name now carries a semantic name, and the data tables have now been interpreted — see Pass 3 data-table inventory below.
Power-on flow analysis
Derived from the disassembly by _tools/derive_poweron.py; the call graph is walked from the reset entry.
RESET is at $CA00 (Reset). The CPU comes here out of reset with the PPU and APU in their power-on state and the zero page and RAM uninitialised.
The reset path calls:
| Address | Routine |
|---|---|
$CA02 |
SubCCA02 (falls through) |
$D07A |
ClearZeroPageLowerHalf |
$CA21 |
SubCCA21 (falls through) |
$D07E |
SubCD07E (falls through) |
$CA2F |
SubCCA2F (falls through) |
$CC67 |
DrawAttractModeBlock |
$CC77 |
HideAllSprites |
$C003 |
ResetSoundEngineState |
$E7EF |
RequestSoundEffectMask2Bits1and6 |
$CA5E |
SubCCA5E (falls through) |
$CC6E |
DrawAttractModeText |
$C063 |
ClearSoundEngineState |
NMI is at $CA91 (NmiHandler). It is the per-frame handler; what it calls:
| Address | Routine |
|---|---|
$CD41 |
DrawPpuBlockList |
$CC85 |
DrawQueuedPpuBlock |
$CCAF |
DrawSpritePpuBlock |
IRQ is at $CA00 (Reset) - the same address as RESET, so the IRQ vector reaches the reset path.
ROM Facts
| Property | Value |
|---|---|
| Mapper | 0 (NROM) — from the iNES header |
| PRG | 16 KB (header claims map at CPU $C000–$FFFF) |
| CHR | 8 KB |
| Mirroring | Vertical |
| Battery-backed flag | clear |
| ROM SHA-256 | 3ec5ac8db623dae34a0f4a4909f0af4569b2af0cee6c56bae512c87b7cff8749 |
| PRG SHA-256 | 13e7f2a77b01784a479895c0535357978af32f5139d971edf5f5b1936585357e |
Interrupt Vectors (taken from PRG $3FFA–$3FFF)
| Vector | Target | Note |
|---|---|---|
| NMI | $CA91 |
per-frame heartbeat |
| RESET | $CA00 |
non-$C000 entry at $CA00 — trace from here in Pass 1 |
| IRQ | $CA00 |
redirects to RESET — unused placeholder |
Project Contents
| File | Purpose |
|---|---|
Urban Champion (JU).nes |
original ROM image (reference) |
prg.bin / header.bin / chr.bin |
split image, produced by _tools/splitnes.py |
prg.s |
Pass 1: classified code/data split re-traced from the Mesen CDL captures, 4,464 instructions, 691 labels, audit comments on every emission; Pass 3: 72 data-table labels added (see the inventory below) |
symbols.inc |
shared NES hardware constants (PPU/APU/controller) |
locals.inc |
153 zero-page aliases (generated ZpXX names) |
linker.cfg |
PRG at $C000, 16 KB, fill = yes |
Makefile |
links reconstructed.nes and cmps it against rom.nes (whole ROM) |
reconstructed.nes |
build output from the last verified build |
urban_baseline.cdl, urban_gameplay.cdl, urban_merged.cdl |
Mesen Code Data Logger captures used for the Pass 1 re-split and for the data-table inventory |
This project is promoted: the build links header.s + prg.s + chr.s and make compares the whole reconstructed.nes against rom.nes, so header, PRG and CHR are all proven.
Build
cd "NROM/Urban Champion (JU)"
make # → cmp reconstructed.nes rom.nes → "Byte-identical ROM verified."
Pass 1 Details
- Tracer seeds: RESET ($CA00), NMI ($CA91), plus
--auto-seedrecovered 34 table-referenced routines. - Forced data override:
$CB70+$3C(a cascade ofbneinstructions that are actually a branch table/data, not code). The fall-through through this region was incorrectly classified as code; forced to data with--data 0xCB70:60. - Overlaps: 6 overlap regions remain (e.g.
$CB8Flsroverlaps$CB91), all in the forced-data region — the conflicting decodes are suppressed in the output. - Invalid opcodes: 7 addresses reached via static trace but decoding invalid opcodes (
$C658,$CAF9,$CB4D,$CC61,$D21B,$DBCE,$DE24). These are marked.bytewith the invalid opcode in the audit comment. - Indirect jumps: 3
jmp ($xxxx)sites at$CDFB($0014),$C318($00EB),$C332($00ED) — targets not statically resolvable. - Zero-page aliases: 153 entries in
locals.inc(auto-generated by tracer).
Open work
- The zero-page aliases in
locals.incare the generatedZpXXnames; the roles are not proven from the code alone. - Eleven blocks decode as code the tracer could not reach and would become
routines if the tracer were re-seeded at their first byte. Three of them are
confirmed executed by the merged CDL —
$CFF2-$D011(32 bytes, every byte of which the CDL records as code),$D0B7-$D0CCand$D46C-$D49C— and they are the clearest targets for a re-trace. They are recorded as code in the inventory rather than being given table names. - The meaning of the byte values in
ScrollStepTable($DFEA) is not established. The table's shape, its index and what the code does with the two bytes of each pair are known; what the numbers mean is not. - The role of
AuxiliaryStateInitialValues($F6D6) — the third of three parallel 32-byte state blocks — is not established; the first two are the two fighters. - The ROM does not name the ten sound slots, so
SoundEffect1..SoundEffect10are the slot numbers, not the sounds' names.
Pass 3 data-table inventory
Every ; ---- data $XXXX-$YYYY ---- region in prg.s is listed here. A
region that is only partly table and partly code says so: the tracer's data
blocks are contiguous runs of bytes it never reached, so a block can hold a
table, a table and unreached code, or code alone.
The evidence for each row is the consuming instruction in this dump, the
bytes themselves, and the merged Mesen CDL capture
(urban_merged.cdl), which records per PRG byte whether the CPU fetched it
as an opcode (Code), read it as data (Data) or executed it.
The sound engine
The largest body of data in this ROM is the sound engine, and its layout falls out of the code:
- The routine at
$C1B2takes a sound slot inY, reads the byte at$C657+Y— a record offset — and then reads nine bytes starting at$C657+offset. The nine bytes are a duration base and four 16-bit pointers, one per APU channel (pulse 1, pulse 2, triangle, noise). The pointers are copied to$F8/$FA/$FC/$FEand read withlda (ZpF8),y,lda (ZpFA),y,lda (ZpFC),yandlda (ZpFE),y. - A note sequence is a stream of command bytes:
$00ends the sequence,$01-$7Fis a pitch,$80-$BFis a duration marker whose following byte is the pitch,$C0-$FEholds a note and$FFstops. - A pitch indexes the period table at
$C100(the APU timer high byte is$C100+nwith bit 3 forced on, the low byte is$C101+n; a zero low byte means "no note"), and a duration marker indexes the length table at$C172through(marker & $0F) + the record's base byte.
The two fighters
The game keeps two parallel 32-byte state blocks in RAM at $0300 and
$0320. Their X positions are at $0303 and $0323, and the routine at
$D1CE subtracts them to measure the gap between the two fighters: a hit
registers only when the gap is between 9 and 24 pixels. $0305/$0325 hold
the two fighters' move states, and $0309/$0329 are the state bytes the
draw routines test. The three tables at $F696, $F6B6 and $F6D6 are the
initial values of those blocks.
Inventory
| Address | Size | Name | Structure | Read by |
|---|---|---|---|---|
$C06A-$C06D |
4 | - | four bytes $3A $7F $0E $40 sitting between the APU-init routine at $C063 and the routine at $C06E. As little-endian words they are $7F3A and $400E; $400E is the APU noise-period register, but nothing in this dump names the pair, so no name is given |
not referenced by any instruction |
$C0A1-$C0AD |
13 | NoiseEnvelopeTable |
13 x 8-bit APU $400C noise-control values, written one per frame while the counter $010A counts up; the final $00 terminates the envelope |
lda $C0A1,y at $C08D |
$C100-$C18C |
141 | NotePitchPeriodTable ($C100), NoteDurationTable ($C172) |
$C100-$C171 = 57 x 16-bit LE APU timer periods, indexed by the (even) pitch number: the high byte is $C100+n with bit 3 forced on, the low byte is $C101+n, and a zero low byte means "no note" (the code branches on it). $C172-$C18C = 27 x 8-bit note lengths in frames, indexed by (duration marker & $0F) + the sound record's base byte |
lda $C172,y at $C02C, lda $C101,y at $C035, lda $C100,y at $C03D |
$C1FE-$C20E |
17 | NoiseControlTable ($C200), NoisePeriodTable ($C201), NoiseLengthTable ($C202) |
$C1FE-$C1FF = two $FF bytes no instruction reaches. $C200-$C20E = three parallel 8-bit arrays of five APU noise values — control ($400C), period ($400E) and length ($400F) — indexed by the same sound index |
lda $C200,y at $C013, lda $C201,y at $C019, lda $C202,y at $C01F |
$C36E-$C375 |
8 | - | eight bytes ($1E $7F $05 $18 $15 $7F $02 $88) that repeat the shape of the noise-effect table at $C200; nothing in this dump names them |
not referenced by any instruction |
$C42C-$C443 |
24 | - | six 4-byte APU pulse-channel presets: duty/envelope ($9F = duty 2, length $1F, constant volume), sweep ($83, $8B, $8D, $82, $93), volume ($E0, $FF) and sweep target/period. Nothing in this dump names them |
not referenced by any instruction |
$C500-$C507 |
8 | - | two more 4-byte APU presets ($B0 $A4 $96 $00 and $B0 $A4 $8D $00) |
not referenced by any instruction |
$C5A0-$C5A3 |
4 | - | four bytes $95 $B5 $40 $B0; read as little-endian words they are $B595 and $B040, which point outside the PRG image, so they are not pointers |
not referenced by any instruction |
$C65C-$C65D |
2 | SoundEffectRecordOffset5, SoundEffectRecordOffset6 |
two bytes of the sound-effect record area. The routine at $C1B2 reads nine bytes per record from $C657+v to $C65F+v (v = the byte at $C657+Y]), and these two supply the low and high bytes of a record's third 16-bit sequence pointer. The same two bytes are entries 5 and 6 of the ten-entry record-offset table that starts at $C657 ($0A $13 $1C $25 $2E $37 $40 $49 $52 $5B); the tracer emitted only $C65C/$C65D of that table as data because the six bytes before it are reached only by falling through the always-taken branch at $C655 |
lda $C65C,y at $C1D5, lda $C65D,y at $C1DA |
$C666-$C9FF |
922 | SoundEffect1Sequence1 ($C937), SoundEffect2Sequence1 ($C810), SoundEffect2Sequence2 ($C82B), SoundEffect2Sequence3 ($C845), SoundEffect2Sequence4 ($C91B), SoundEffect3Sequence1 ($C874), SoundEffect3Sequence2 ($C85F), SoundEffect3Sequence3 ($C87E), SoundEffect3Sequence4 ($C893), SoundEffect4Sequence1 ($C93D), SoundEffect4Sequence2 ($C958), SoundEffect4Sequence3 ($C972), SoundEffect5Sequence1 ($C8A7), SoundEffect5Sequence2 ($C8D3), SoundEffect5Sequence3 ($C8FE), SoundEffect6Sequence1 ($C983), SoundEffect6Sequence2 ($C99C), SoundEffect6Sequence3 ($C9B2), SoundEffect6Sequence4 ($C9C8), SoundEffect7Sequence3 ($C76A), SoundEffect7Sequence4 ($C7E9), SoundEffect8Sequence1 ($C6BB), SoundEffect8Sequence2 ($C6FD), SoundEffect8Sequence3 ($C73B), SoundEffect8Sequence4 ($C761), SoundEffect9Sequence3 ($C799), SoundEffect10Sequence3 ($C7C6) |
the sound-effect record table and the note sequences its pointers name. The ten nine-byte records sit at $C661+9n (a duration base byte and four 16-bit pointers, one per APU channel); the record area straddles the block's first boundary, because the tracer emitted $C661/$C662 in a .byte row before it and decoded $C663-$C665 as instructions. The twenty-seven sequences that follow are zero-terminated command streams (see The sound engine above). SoundEffect7Sequence4 is shared by slots 7, 9 and 10; SoundEffect2Sequence4 is shared by slots 2, 4 and 5 |
lda (ZpF8),y at $C225 and $C239, lda (ZpFA),y at $C263 and $C274, lda (ZpFC),y at $C29E and $C2CA, lda (ZpFE),y at $C2F4 and $C303, through the pointers in the records at $C661+9n |
$CAF8-$CAF8 |
1 | - | a single $F0 — the BEQ opcode — between cpy #$03 at $CAF6 and the routine at $CAF9 |
not referenced by any instruction |
$CB4A-$CB4A |
1 | - | a single $A5 (LDA immediate) between two instructions |
not referenced by any instruction |
$CB4D-$CB4D |
1 | - | a single $03; the tracer reached it but the opcode is not a valid 6502 instruction |
not referenced by any instruction |
$CB6B-$CB73 |
9 | - | the branch cascade around $CB70. The bytes decode as 4 consecutive instructions, but the merged CDL records six of them being read as data and three as jump targets, so they are the branch offsets of a dispatch table rather than code |
not referenced by any instruction; the merged CDL records six of the bytes being read as data and three as jump targets |
$CB76-$CB77 |
2 | - | unreferenced; two bytes in the branch cascade around $CB70 |
not referenced by any instruction |
$CB7E-$CB81 |
4 | - | unreferenced; four bytes in the branch cascade around $CB70 |
not referenced by any instruction |
$CB8E-$CB8E |
1 | - | a single $CC (CPY immediate) |
not referenced by any instruction |
$CB92-$CB92 |
1 | - | a single $5E; the merged CDL records it as an opcode fetch, so it is the start of an instruction the tracer could not reach |
not referenced by any instruction |
$CB9C-$CB9C |
1 | - | a single $A2 (LDX immediate); the merged CDL records it as an opcode fetch |
not referenced by any instruction |
$CBA2-$CBA2 |
1 | - | a single $A2 (LDX immediate); the merged CDL records it as an opcode fetch |
not referenced by any instruction |
$CC61-$CC66 |
6 | - | three 16-bit LE pointers into the PRG image ($CFC3, $CFF2, $D00F) — a dispatch table. No instruction in this dump names it, but the merged CDL records all six bytes being read as data: the indirect read that reaches it is one the tracer cannot follow |
not referenced by any instruction (read indirectly, per the CDL) |
$CFF2-$D011 |
32 | - | unreferenced by any instruction, but the merged CDL records every byte of it as code and the block was executed. It is code the tracer could not reach, not data | not referenced by any instruction (executed, per the CDL) |
$D0B7-$D0CC |
22 | - | unreferenced; 18 of the 22 bytes are recorded as code by the merged CDL — code the tracer could not reach | not referenced by any instruction |
$D152-$D173 |
34 | - | unreferenced; decodes as a straight-line routine (lda $2B / bne / lda #$01 / sta $0301 / sta $0321 / sta $0341 / lda #$03 / sta $25 / rts / the same stores with $00 / jmp $D1A4) — code the tracer could not reach |
not referenced by any instruction |
$D21B-$D242 |
40 | - | 20 x 16-bit LE code pointers into the PRG image ($D2B2, $D26E, $D361, $D3FA, $D398, $D36C, $D4C4, $D5A2, $D5C4, $D656, $D501, $D6AB, $D261, $D80C, $D834, $D875, $D8B4, $D8EA, $D916, $D97D) — a dispatch table. No instruction in this dump names it; the merged CDL records ten of its bytes being read as data |
not referenced by any instruction (read indirectly, per the CDL) |
$D344-$D34A |
7 | - | unreferenced; decodes as lda $88 / beq / jmp $D29E — code the tracer could not reach |
not referenced by any instruction |
$D361-$D366 |
6 | - | unreferenced; decodes as lda $3E / beq / dec $3E — code the tracer could not reach |
not referenced by any instruction |
$D46C-$D49C |
49 | - | unreferenced; 42 of the 49 bytes are recorded as code by the merged CDL — code the tracer could not reach | not referenced by any instruction |
$D656-$D7DA |
389 | - | unreferenced; the merged CDL records no execution of it, but the bytes decode as 183 consecutive instructions, so it is code the tracer could not reach rather than data | not referenced by any instruction |
$D8B4-$DA10 |
349 | - | unreferenced; decodes as 166 consecutive instructions — code the tracer could not reach | not referenced by any instruction |
$DAD9-$DB04 |
44 | - | unreferenced; decodes as 20 consecutive instructions (lda $A0 / beq / lda #$32 / ldx #$14 / sta $0500,x / dex / bpl / the PPU buffer setup) — code the tracer could not reach |
not referenced by any instruction |
$DBCE-$DBD0 |
3 | - | three bytes that decode as the undocumented opcode $DB and its operand; not a table |
not referenced by any instruction |
$DDD1-$DDF6 |
38 | - | unreferenced; decodes as 21 consecutive instructions — code the tracer could not reach | not referenced by any instruction |
$DE24-$DE26 |
3 | - | the first three bytes of a six-entry 16-bit LE code-pointer table ($DE36, $DEC9, $DED8, $DEF0, $DEF4, $DF19) that the tracer split in two, because it decoded the bytes in between as instructions. No instruction in this dump names it; the merged CDL records the three bytes being read as data |
not referenced by any instruction (read indirectly, per the CDL) |
$DE2D-$DE30 |
4 | - | the tail of the same six-entry code-pointer table. The merged CDL records two of its bytes being read as data | not referenced by any instruction (read indirectly, per the CDL) |
$DEC9-$DECC |
4 | - | unreferenced; decodes as lda #$01 / sta $19 — code the tracer could not reach |
not referenced by any instruction |
$DFEA-$E03F |
86 | ScrollStepTable ($DFEA), ScrollTargetTable ($E00C) |
$DFEA-$E00B = 17 x (byte, byte) pairs indexed by the current scroll row ($8F x 2): the first byte is loaded into $8E and counted down (the code at $DF42 tests it and $DF53 decrements it), the second into $AC. $E00C-$E03F = 25 x (X, Y) pairs — the scroll targets — indexed by the waypoint number ($71 x 2) and used by the loop at $DFDA that walks the background scroll to the target. What the byte values mean is not established |
lda $DFEA,x at $DF60, lda $DFEB,x at $DF65, lda $E00C,x at $DFCB, lda $E00D,x at $DFD0 |
$E082-$E08C |
11 | - | eleven bytes the merged CDL records as data but that no instruction in this dump names; as little-endian words they are $E9E0, $FCE0, $1DE0, $C0E1, $ABE1, which is not a recognisable structure |
not referenced by any instruction (read indirectly, per the CDL) |
$E3C6-$E3DF |
26 | SpriteTileIndexTable ($E3C6), SpriteAttributeTable ($E3C7), AlternateSpriteTileTable ($E3D7) |
$E3C6-$E3D6 and $E3C7-$E3D7 are two parallel 17-byte tables indexed by the sprite number $72: a CHR tile index (copied to the PPU write buffer at $0501) and an OAM attribute byte (kept in $0C and OR-ed into the sprite's attribute at $E6A6). $E3D7-$E3DF = nine more CHR tile indices, copied to $04F7-$04FF when $72 is $12 |
lda $E3C7,x at $E35A, lda $E3C6,x at $E35F, lda $E3D7,x at $E390 |
$E813-$FFFF |
6125 | SpriteOffsetTable ($E8E5), PpuBlockPointerTable1 ($F5B2), PpuBlock1 ($F5BE), PpuBlock2 ($F5D6), PpuBlock3 ($F5FA), PpuBlock4 ($F61E), PpuBlock5 ($F642), PpuBlock6 ($F666), InitialOamRecords ($F68A), Player1StateInitialValues ($F696), Player2StateInitialValues ($F6B6), AuxiliaryStateInitialValues ($F6D6), FighterOamRecords ($F6F6), Player1TileStrip ($F747), Player2TileStrip ($F75C), PpuBlockPointerTable2 ($F771), ScriptBlockPointerTable ($F77D), ScriptBlock1 ($F7AF), ScriptBlock2 ($F7B6), ScriptBlock3 ($F7BD), ScriptBlock4 ($F7C4), ScriptBlock5 ($F7CE), ScriptBlock6 ($F7D7), ScriptBlock7 ($F7E0), ScriptBlock8 ($F7E3), ScriptBlock9 ($F7E6), ScriptBlock10 ($F7E9), FighterMotionScript ($F7F1), BackgroundOamRecords ($F8CC), StatusTileList ($F941), PpuBlockPointerTable3 ($F949), PpuBlockPointerTable4 ($F9CF) |
the game's graphics and script data. $E8E5-$E8F4 = 16 per-sprite position offsets. $F5B2-$F5BD = six 16-bit LE pointers to PPU write blocks — each block is [PPU address high][PPU address low][tile count][tile bytes], and the routine at $CDFE writes them to the nametable; the six blocks at $F5BE, $F5D6, $F5FA, $F61E, $F642 and $F666 write to $3F00. $F68A-$F695 = three identical 4-byte records $00 $01 $20 $00, copied to $05F0-$05FB by the reset path at $CA5E (nothing in this dump reads that RAM). $F696, $F6B6 and $F6D6 = the three 32-byte initial values of the RAM state blocks at $0300, $0320 and $0340 (the first two are the two fighters — see The two fighters above). $F6F6-$F745 = twenty 4-byte OAM records (Y, tile, attribute, X) for a fighter graphic, ended by a $2F Y byte. $F747 and $F75C = the two players' tile strips, each a list of CHR tile indices ended by $FF, drawn when the player's state byte $0309/$0329 is 1. $F771-$F77C = five more PPU write blocks (plus a null entry). $F77D-$F790 = ten 16-bit LE pointers to script blocks: each is a list of (value, value) pairs ended by $FE or $FF. $F7F1 = the fighter motion script: (dx, dy) pairs added to the fighter's position at $32/$33, with $FD (a one-byte parameter), $FE (branch back three bytes) and $FF (end) as commands. $F8CC-$F8E7 = seven more 4-byte OAM records, copied to $0240-$025B (the OAM shadow's sprites 16-22). $F941-$F948 = eight CHR tile indices copied to the PPU write buffer at $0500. $F949 and $F9CF = two more pointer tables to nametable row blocks |
lda $F68A,x at $CA5E, lda $F5B2,y at $CC8D and ldx $F5B3,y at $CC90, lda $F771,x at $D178 and ldy $F772,x at $D17B, lda $F747,x at $DA4F, lda $F75C,x at $DA80, lda $F940,y at $DBAA, lda $F6FA,y at $DCD4, lda $F6F6,y at $DCE7, lda $F8CC,x at $DDF9, lda $F9CF,x at $E23C and lda $F9D0,x at $E241, lda $F7F1,y at $E41A, $E42F, $E435, $E43B and $E444, lda $F696,x at $E4C2, lda $F6B6,x at $E4CD, lda $F6D6,x at $E4D8, lda $F77D,y at $E4FE and ldx $F77E,y at $E501, lda $E8E5,x at $E65C and $E6B1, lda $F949,x at $E71A and lda $F94A,x at $E71F |
Notes on the blocks that are not tables
- The blocks that "decode as N consecutive instructions" are code, not data:
the tracer never reached them, so they are still emitted as
.byterows, but their contents are instructions. They are left unnamed here on purpose; seeding the tracer at the first byte of each would turn them back into routines. The merged CDL confirms three of them ($CFF2-$D011,$D0B7-$D0CCand$D46C-$D49C) were actually executed during the recorded session. - The one-byte regions at
$CAF8,$CB4A,$CB4D,$CB8E,$CB92,$CB9Cand$CBA2hold a single byte each and sit between two instructions; they are stray bytes, not tables. $C06A-$C06D,$C36E-$C375,$C42C-$C443,$C500-$C507and$C5A0-$C5A3all sit in and around the sound engine and hold APU constants, but no instruction in this dump names them, so they are recorded here with their contents rather than given a name.$CC61-$CC66,$D21B-$D242,$DE24-$DE26,$DE2D-$DE30and$E082-$E08Care read by the CPU — the CDL says so — but not by any instruction this dump contains: the reads are indirect and the tracer cannot follow them. They are left unnamed for the same reason.- The layout of the
$F6F6OAM record list and of the tenScriptBlocks is established, but the game names behind them are not: the ROM never says which sound is which slot, and the ten script blocks are not identified either.
Pass 2 Details
The Pass 1 split was re-done from the Mesen CDL captures after the project was promoted, so the semantic renaming was redone on the new split. What the dump establishes about the game's structure is recorded here and in the data-table inventory above.
- Routine names: every routine the game reaches through a
jsror ajmpcarries a semantic name. The sound engine is named for what it does to the APU (UpdateSoundEngine,UpdateApuChannels,LoadSoundEffectRecord,WritePulse1PeriodAndTimer,LookupNoteDuration, ...), the graphics side for what it draws (DrawPpuBlockList,DrawQueuedPpuBlock,QueuePpuBlocks,HideAllSprites, ...), the controller code for what it reads (ReadControllers,ReadControllerButtons), and the sound-request helpers for the mask bit each of them sets (RequestSoundEffectSlot0,RequestPulse1Preset0,StopAllSound, ...). The three vector entries (Reset,NmiHandler) and the 72 data-table labels are named as well. The oldlabel_map.tsvandroutinemap.tsvin this folder refer to the pre-re-split disassembly and no longer matchprg.s. - Zero-page aliases: the generated
ZpXXnames inlocals.incare still in place; the behavioural aliases of the earlier pass have to be re-derived. - The 4,464 traced instructions are unchanged in the re-split; what changed is which of them the tracer could reach.
Mesen CDL Verification
This folder holds three Code Data Logger captures: urban_baseline.cdl,
urban_gameplay.cdl and their merge urban_merged.cdl. The jump-target
flag in a capture names the addresses the CPU actually branched to, and
re-tracing with those seeds reaches the code behind the game's computed
dispatch. Every "code the tracer could not reach" row of the inventory above
was checked against the merged capture.
| Region | Merged CDL | Disposition |
|---|---|---|
$C006-$C025, $C032-$C04D, $C22F-$C24C, $C26A-$C287, $C2A8-$C2DD, $C2F9-$C30B |
CODE | missed init routines — now code in the re-split |
$CFC3-$D011, $D09D-$D173, $D469-$D7DA, $DBFD-$DCF5, $DE21-$DEC8, $DED8-$DF4B, $E11D-$E1CC, $E350-$E40D |
CODE | missed routines — now code in the re-split |
$CFF2-$D011 |
CODE, and executed | still a data block: the tracer cannot follow the indirect read that reaches it |
$D0B7-$D0CC, $D46C-$D49C |
CODE | still data blocks; code the tracer could not reach |
$CB6B-$CBA2 |
DATA | the branch cascade is dead — confirmed |
$CC61-$CC66, $D21B-$D242, $DE24-$DE30, $E082-$E08C |
DATA | read by the CPU through an indirect read the tracer cannot follow |