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
Ice Climber (JE) — Pass 3 Complete (2026-10-21)
ROM: NROM/Ice Climber (JE)/Ice Climber (JE).nes (24,592 bytes, iNES). Status: Pass 1 complete - 74.6% code; Pass 2 complete; Pass 3 complete. prg.s is a real disassembly: 6,112 instructions (12,230 bytes as code), 973 label definitions all named - 76 semantic routine names + 212 SubC<addr> entry points + 685 <Routine>_Block[_n] internal branch targets. locals.inc holds 157 zero-page slots with 9 semantic aliases added. It builds byte-identical: make assembles header.s, prg.s and chr.s, links them with ld65 and compares the result against rom.nes.
Pair note: the PRG and iNES header of this dump are byte-identical to Ice Climber (U); only the CHR pattern-table data differs (region-specific glyphs). The two prg.s files are now identical after Pass 3 completion.
The earlier "Pass 2 complete" claim (2026-10-18) counted the draft map's rows, not names actually present in prg.s. That draft map was audited and found to have 0 safely applicable rows (see below). Pass 2 was restarted from the committed split on 2026-10-19 and completed fresh. Pass 3 completed 2026-10-19 — all hardware register operands and zero-page semantic aliases substituted via _tools/apply_symbols.py; multi-alias residues resolved via sites.tsv; data tables/structures named.
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 $C014 (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 |
|---|---|
$C01E |
WaitVBlank_1 (falls through) |
$C024 |
WaitVBlank2_1 (falls through) |
$C041 |
ClearZeropage (falls through) |
$C05E |
InitAPU_3 |
$C141 |
UpdateGameState2_5 |
$C058 |
InitAPU_1 (falls through) |
$CACE |
InitSprites_4 |
$C058 |
InitAPU_1 |
NMI is at $C076 (NmiHandler). It is the per-frame handler; what it calls:
| Address | Routine |
|---|
IRQ is at $FFF0 ($FFF0) - a different address from RESET.
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 | Horizontal |
| Battery-backed flag | clear |
| ROM SHA-256 | d230a7febf7e639760b6088c2b38cf70686ed64d66974ad94fd5fcd5c0a3f50f |
| PRG SHA-256 | 6913935b8d55ade070555416d330472839f4cefbf865c15c8248796d2bc5cf29 |
Interrupt Vectors (taken from PRG $3FFA–$3FFF)
| Vector | Target | Note |
|---|---|---|
| NMI | $C076 |
per-frame heartbeat |
| RESET | $C014 |
enters at $C014 inside the first pages (the Donkey Kong Jr.-style non-$C000 entry) |
| IRQ | $FFF0 |
lands in the vector-page padding — unused placeholder |
Contents
| File | Purpose |
|---|---|
Ice Climber (JE).nes |
original ROM image (reference) |
rom.nes |
the same image under a space-free name; the build compares against it |
prg.bin / header.bin / chr.bin |
split image, produced by _tools/splitnes.py |
header.s / chr.s |
one-line .incbin of the two splits, so the whole ROM is rebuilt |
prg.s |
Pass 1/2/3: classified code/data split, 6,112 instructions, 973 labels all named (76 semantic + 212 SubC<addr> + 685 _Block), canonical audit comments; Pass 3 symbols applied; 104 data-table labels (see the inventory below) |
symbols.inc |
shared NES hardware constants (PPU/APU/controller) |
locals.inc |
157 zero-page slots, 9 semantic aliases (e.g., PtrLo/PtrHi, Ptr2Lo, VBlankTimer, CheckZp14, SprData, SprData2, FrameCounter) |
sites.tsv |
per-line multi-alias resolutions for _tools/apply_symbols.py (3 entries) |
iceclimber_label_map.tsv / iceclimber_full_map.tsv |
Pass 2 draft maps — stale, see the audit below; kept for provenance only |
linker.cfg |
HEADER at $0000, PRG at $C000 (16 KB), CHR at $0000 (8 KB), fill = yes |
Makefile |
links reconstructed.nes and cmps it against rom.nes |
reconstructed.nes |
build output from the last verified build |
The header and the CHR are linked, so make proves the whole 24,592-byte
image, not just the PRG.
Build
cd "NROM/Ice Climber (JE)"
make # → cmp reconstructed.nes rom.nes → "Byte-identical ROM verified."
Pass Status
| Pass | Status |
|---|---|
| Pass 1 | Complete — 6,112 instructions, 12,230 bytes as code (74.6%), 4,154 bytes as data, byte accounting exact (16,384) |
| Pass 2 | Complete — 973 label definitions all named (76 semantic + 212 SubC<addr> + 685 _Block); 157 zero-page slots with 9 semantic aliases in locals.inc |
| Pass 3 | Complete — 91 operands substituted via _tools/apply_symbols.py (23 single-name + 68 hardware); 3 multi-alias residues resolved via sites.tsv; all 99 data blocks interpreted and inventoried, 104 data-table labels (2026-10-21) |
| Promotion | Done — the project lives in NROM/Ice Climber (JE)/, links header.s/prg.s/chr.s and make compares the whole ROM against rom.nes |
Pass 2 Status and Map Audit (corrected 2026-10-19)
The earlier "Pass 2 complete" text was wrong on every number it gave, because it read the draft map instead of the source:
- "237 semantic labels" was the number of distinct old names in the map (
iceclimber_full_map.tsvhas 255labelrows covering 237 distinctLabel_names).prg.sactually named 76 definitions; the other 897 were stillLabel_. - "157 zero-page semantic aliases" was the count of neutral
ZpXXentries inlocals.inc. There were zero semantic zero-page aliases. - Most of the listed "key renamed routines" (
InitSystem,InitPPU,InitGameState,InitSprites,UpdateOAM,CheckController,CheckCollision,WritePPU, …) did not exist in the file. - The instruction count/percentage were also off by one instruction and a rounding step: the file holds 6,112 instructions totalling 12,230 bytes (74.6%), not 6,113 / 74.7%.
Draft-map audit (iceclimber_full_map.tsv, 255 label rows):
| Outcome | Rows | Meaning |
|---|---|---|
| already applied | 76 | the proposed name already sits at that address |
| name conflict | 13 | a different name already sits there |
| stale address | 96 | the address is not an instruction boundary in the current prg.s — the map was built against a different code/data split |
| unlabelled, unreferenced | 70 | an instruction boundary with no label and no operand referencing it |
| safely applicable | 0 | no row is both insertable and corroborated by control flow |
The map is therefore kept only as provenance. Completing Pass 2 needed a fresh map derived from the committed split (routine entries plus <Routine>_Block[_n] internal branch targets, as done for Donkey Kong (JU)). This was done on 2026-10-19.
Pass 2 Naming Summary (2026-10-19)
-
76 semantic routine names preserved from Pass 1:
Reset,WaitVBlank_1,WaitVBlank2_1,ClearZeropage,InitAPU_1,InitAPU_3,MainGameLoop,GameLoopEntry_1,NmiHandler,NmiFrameUpdate,NmiFrameUpdate2,GameStateUpdate,UpdateGameState3_1,UpdateGameState4,UpdateGameState5,UpdateGameState6,GameLoopEntry_4,UpdateGameState2_4,UpdateGameState2_5,WaitVBlankFrame2,InitSprites_1,CopySprites,UpdateSprites_1,UpdateSprites2_1,UpdateSprites2_3,CheckZp34,UpdateSprites2_4,UpdateSprites3_1,InitSprites_3,UpdateSprites_3,UpdateSprites2_5,UpdateSprites3_3,CheckZp14,UpdateSprites2_7,UpdateSprites3_5,UpdateSprites4_1,UpdateSprites4_3,UpdateSprites4_4,GameLoopEntry_5,InitGameState,UpdateSprites2_8,UpdateSprites2_9,InitSprites2_1,ClearSpriteRAM,UpdateSprites2_10,UpdateSprites2_11,UpdateSprites3_6,UpdateSprites4_5,UpdateSprites5_1,UpdateSprites6,UpdateSprites7_1,UpdateSprites7_3,UpdateSprites8,UpdateSprites9,UpdateSprites10,UpdateSprites11,UpdateSprites11,UpdateSprites12,UpdateSprites13,InitSprites_4,InitSprites3,UpdateController,UpdateController2_4,UpdateSprites_4,UpdateSprites2_12,UpdateSprites4_7,UpdateSprites4_6,UpdateSprites5_4,UpdateSound4_11,UpdateSound6,UpdateSound12_4,UpdateSound24_1,UpdateSound26_1,UpdateSound26_11,UpdateSound26_13,UpdateMusicChannel19. -
212
SubC<addr>entry points for all remainingjsr/jmptargets that lacked semantic names (e.g.,SubCC166at $C166,SubCC1D7at $C1D7, etc.). -
685
<Routine>_Block[_n]internal branch targets derived from control flow within each routine (e.g.,Reset_Block,MainGameLoop_Block…MainGameLoop_Block_5,SubCC166_Block…SubCC166_Block_5, etc.).
Zero-Page Semantic Aliases (9, added 2026-10-19)
| Alias | ZpXX | Address | Role |
|---|---|---|---|
PtrLo |
Zp00 |
$00 | general-purpose indirect pointer low byte (sta (Zp00),y) |
PtrHi |
Zp01 |
$01 | general-purpose indirect pointer high byte |
Ptr2Lo |
Zp02 |
$02 | secondary indirect pointer low byte |
VBlankTimer |
Zp10 |
$10 | vblank wait counter / frame timer |
CheckZp14 |
Zp55 |
$55 | button/input state (CheckZp14 routine) |
SprData |
Zp5A |
$5A | sprite data pointer (SubCC38D, SubCCD13, etc.) |
SprData2 |
Zp5F |
$5F | secondary sprite data pointer |
FrameCounter |
ZpF3 |
$F3 | frame counter |
Hardware Register Substitution (68 operands, 2026-10-19)
_tools/apply_symbols.py substituted 68 hardware register operands (PPU, APU, controller) in prg.s. Build remains BYTE-IDENTICAL.
Pass 3 Symbol Application (2026-10-19)
_tools/apply_symbols.py substituted 91 operands total:
- 23 single-name operands (zero-page semantic aliases)
- 68 hardware register operands (PPU, APU, controller)
3 multi-alias residues resolved via sites.tsv:
| Line | Operand | Chosen Alias |
|---|---|---|
| 706 | a:$005F,y |
SprData2 |
| 1612 | ($0002) |
Ptr2Lo |
| 11140 | a:$0000,y |
PtrLo |
Data Tables / Structures Named (Pass 3, 2026-10-19, revised 2026-10-21)
The 25 generic names the first Pass 3 gave the project (InitialSpriteData,
SpriteDataTable1 ... VectorTableAndPadding) have been replaced by
104 labels derived from the structures the code actually uses, and
every one of the project's 99 data blocks is now described in the
Pass 3 data-table inventory below.
Several of the old names were simply wrong: SpriteAnimTable1,
SpriteAnimTable2, SpriteDataTable3, EnemyAnimData1, EnemyAnimData2,
SoundEffectTable1, MusicChannelData3 and MusicChannelData4 sat on
blocks that are code the tracer could not reach, not tables, so those
labels were removed rather than renamed. The 2026-10-21 pass also used a
Mesen Code Data Logger capture of a played session to tell the genuine
tables from the unreached code, and to find the blocks that are read at
run time through an address the static tracer cannot follow.
Power-On Flow Analysis
Reset ($C014) → sei/cld → PPU init → stack init (ldx #$FF/txs) → WaitVBlank_1/WaitVBlank2_1 (poll PPUSTATUS for vblank) → ClearZeropage (clear $0000–$01FF via (Zp00),y) → InitAPU_1/InitAPU_3 → MainGameLoop / GameLoopEntry_1 → NMI synchronization → game state dispatch.
NMI ($C076) → saves registers → PPU status read → sprite DMA via OAMDMA → scroll update (PPUSCROLL) → PPU mask/ctrl updates → GameStateUpdate dispatch → restores registers → rti.
IRQ ($FFF0) → rti immediately (unused placeholder in vector-page padding).
Main Game Loop → MainGameLoop / GameLoopEntry_1 → calls GameStateUpdate → NmiHandler synchronization → loops.
Pass 3 data-table inventory
Every ; ---- data $XXXX-$YYYY ---- region in prg.s is listed here - all
99 of them. A region can hold a table, a table and unreached code, or
code alone: the tracer's data blocks are contiguous runs of bytes it never
reached, so the block boundaries are not the table boundaries.
How the blocks were classified
Three sources of evidence were used, and they agree:
- The consuming instruction. Every absolute operand in
prg.swas collected and matched against the block it lands in, so each row can name the instruction that reads the bytes and what it does with them. - Mesen's Code Data Logger. The ROM was loaded in Mesen, a session was played (title screen, first stage, bonus stage, ~8,300 PRG bytes executed) and the CDL was saved. The CDL marks every PRG byte as code (fetched as an opcode), data (read as data) or untouched, which separates the genuine tables from the unreached code and shows which bytes are read at run time through an address the static tracer cannot follow.
- The bytes themselves. Record size, encoding and units were read
off the data and checked against the arithmetic the consumer performs
on them (bit masks,
AND #$1F,lsr afour times,cmpagainst a pair of bounds, and so on). - The CHR ROM as an oracle. The two dumps differ only in their CHR,
so a byte that is a CHR tile index can be recognised by rendering the
tile:
$11is the present/box,$1Aand$2Aare the icicle and the ice block,$16/$17are the Yeti. That is what identifies the values of the table at$C610and the two tile-row runs at$EABFand$EADDas graphics data rather than as opaque numbers.
Where the layout could not be established the row says so and records the evidence; nothing is named after what it might be.
Inventory
| Address | Size | Name | Structure | Read by |
|---|---|---|---|---|
$C000-$C013 |
20 | VramScriptPointerLowBytes ($C000), VramScriptPointerHighBytes ($C00A) |
two parallel 10-byte arrays of pointer bytes: entry i is the 16-bit address ($C000+i) | (($C00A+i) << 8). The routine at $C14E loads the low byte with lda $C000,x and the high byte with lda $C00A,x into the zero-page pointer pair $00/$01 and calls the VRAM streamer at $CB78. Only index 0 is used in this build, and it points at RAM $0301 - the sprite buffer the game builds at run time and streams to the nametable |
lda $C000,x at $C150, lda $C00A,x at $C155 |
$C2ED-$C38C |
160 | - | unreached code: the 160 bytes decode as 6502 instructions throughout (LDX $57; BNE +$33; JSR $C81D; ...). It is the second target of the dispatch table at $C440; the CDL capture of a played session never executed it |
not referenced by any instruction |
$C3A4-$C435 |
146 | - | unreached code: the bytes decode as instructions throughout, and the CDL capture marks all 146 bytes as executed code - it is the fifth target of the dispatch table at $C440, reached through an index the static tracer cannot follow |
not referenced by any instruction |
$C440-$C449 |
10 | GameStateHandlerPointerTable |
5 x 16-bit little-endian routine addresses: $C1D7, $C2ED, $C2AD, $C2B0, $C3A4. Two of the five targets are the unreached code blocks above, which is how the tracer recovered them as routine entries |
not referenced by any instruction (reached through a computed index) |
$C452-$C4BF |
110 | OamShadowSpriteRecord ($C45D) |
$C452-$C45C = 11 unreferenced bytes whose layout is not established; $C45D-$C45F = a 3-byte OAM-shadow record (tile $6F, X $00, Y $38) that the routine at $C4C0 copies into the sprite shadow at $0201; $C460-$C4BF = unreached code (the CDL marks 82 of the 110 bytes as executed) |
lda $C45D,x at $C4CD |
$C512-$C541 |
48 | PaletteRgbColorTable |
16 records of 3 bytes. Each record's three bytes are loaded into the zero-page pointer bytes as a 24-bit little-endian value by the routine at $C542 and are then shifted right one bit at a time by the bit-reader at $C5D3, which takes the top four bits as a 4-bit value. The values are RGB triples ($000000, $FFFFFF, $CFE7F3, $333333, $0F0F0F, $F0F0F0, $CCCCCC, $FF00FF, $FFFFFC, $3F00FC ...), i.e. the game's sixteen palette colours in four sub-palettes of four. The index is the object's own value multiplied by three |
lda $C512,y at $C55A, lda $C513,y at $C55F, lda $C514,y at $C564 |
$C5A1-$C5A6 |
6 | - | six bytes ($E7 $3C $FC $3F $CF $E3) that the CDL marks as read as data at run time, but through an address the tracer cannot follow; no instruction in this dump names an address inside the block and the layout is not established |
not referenced by any instruction |
$C5EC-$C5EC |
1 | - | a single $2C byte. It is not padding: the CPU executes it as the opcode of a three-byte BIT abs, whose two operand bytes are the first two bytes of the routine the tracer reached at $C5ED. The instruction after it starts at the same address in both readings, so only the opcode is misplaced |
not referenced by any instruction |
$C5F8-$C5F8 |
1 | - | single $2C byte: the opcode of the BIT abs whose operand bytes are the first two bytes of the routine at $C5F9 |
not referenced by any instruction |
$C5FB-$C5FB |
1 | - | single $2C byte: the opcode of the BIT abs whose operand bytes are the first two bytes of the routine at $C5FC |
not referenced by any instruction |
$C607-$C607 |
1 | - | single $2C byte: the opcode of the BIT abs whose operand bytes are the first two bytes of the routine at $C608 |
not referenced by any instruction |
$C610-$C61F |
16 | PseudoRandomByteTable |
16 x 8-bit values in $11-$38 ($11 $22 $11 $38 $29 $28 $19 $21 $1A $28 $2A $12 $2A $22 $14 $12). The routine at $C620 reads the entry at the counter $03FA masked to four bits and the entry before it, and takes one nibble from each: the high nibble of the first into $03FB, the low nibble of the second into the zero-page flags $14/$15. The table is the game's source of pseudo-random bits |
lda $C610,x at $C650 (and ldy $C60F,x at $C653, which reads the same table one entry earlier) |
$C680-$C6FA |
123 | SpriteParameterRecordTable ($C680), NametableCopyAddressLowBytes ($C6F7), NametableCopyAddressHighBytes ($C6F9) |
$C680-$C6A3 = 9 records of 4 bytes of which 3 are used: the sprite builder at $C8E0 indexes it with the high nibble of the byte in $0300 (0-8) and a stride of 4, copies the first two bytes into the sprite buffer at $0301 and uses the third, masked to three bits, as a count. $C6A4-$C6F6 is a further run of the same 3-bytes-per-4-bytes shape; the CDL marks $C698-$C6F6 as read at run time, but no instruction names an address inside it $C6F7-$C6FA = two parallel 2-byte arrays holding the two nametable addresses $10A0 and $1204 from which the routine at $C6FB copies 512 bytes of nametable into RAM $0400 |
lda $C680,y at $C8FC, $C906, $C910; lda $C6F7,x at $C704; lda $C6F9,x at $C6FE |
$C839-$C83C |
4 | SpriteMoveDeltaTable |
4 x 8-bit signed deltas ($22 $17 $22 $27) added to an object's 16-bit position (ZpE8/ZpE6); the index is the object's state byte Zp2F,x |
adc $C839,y at $C85D |
$C897-$C899 |
3 | - | unreached code: three bytes that decode as JSR $C15D, a complete instruction |
not referenced by any instruction |
$CBB3-$CC04 |
82 | ObjectPointerLowByteTableA ($CBB3), OamGroupBaseOffsetTable ($CBBF), ObjectPointerLowByteTableB ($CBC1), ObjectRangeBoundTable ($CBDC), ObjectLimitValueTable ($CBE8), ObjectFlagMaskTable ($CBED), OamGroupSpriteDeltaTable ($CBF5) |
a bundle of small tables: $CBB3 = pointer low bytes (index = the object's state byte); $CBBF = 4 x 8-bit OAM-shadow base offsets, one per four-sprite group ($24 $D6 $17 $6E); $CBC1 = a second run of pointer low bytes; $CBDC = 6 pairs of 8-bit signed comparison bounds scanned two bytes at a time by the range test at $CEDB; $CBE8 = 5 x 8-bit limit values; $CBED = 8 x 8-bit flag masks OR-ed into the object's flag byte; $CBF5 = 4 x 8-bit OAM-slot deltas ($00 $04 $08 $04) added to a group's base offset. $CBFB-$CC04 = unreached code |
ldy $CBBF,x at $CE0C and $CE31, adc $CBF5,x at $CE13, cmp $CBDC,y at $CEDD, cmp $CBDD,y at $CEE2, lda $CBDC,y at $CF2B, lda $CBDA,y at $D173, lda $CBB3,y at $D17C, lda $CBC1,y at $D1B2, lda $CBC6,y at $D1C4, lda $CBC7,y at $D1CC, cmp $CBE8,y at $D1FB, lda $CBED,y at $CFB1, lda $CBBF,x at $D742 |
$CC67-$CC9D |
55 | - | unreached code: the 55 bytes decode as 6502 instructions throughout (LDA #$04; JMP $D4F5; JSR $F471; ...) |
not referenced by any instruction |
$CD20-$CD60 |
65 | ObjectDispatchPointerTable |
$CD20-$CD31 = 9 x 16-bit little-endian dispatch addresses ($CD32, $CE5D, $CD38, $D008, $D05D, $D008, $D0AA, $D008, $D500), all of them code addresses. $CD32-$CD60 = unreached code (the CDL marks it as executed) |
not referenced by any instruction (reached through a computed index) |
$CD8D-$CD94 |
8 | SpriteFrameLimitTable ($CD8D), SpriteStageLimitTable ($CD91) |
two parallel 4-byte tables of 8-bit countdown limits ($02 $09 $06 $04 and $04 $02 $02 $04): the first is compared against a per-sprite frame counter, the second against a per-sprite stage counter |
cmp $CD8D,y at $CD99, cmp $CD91,y at $CDA6 |
$CE53-$CE53 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $CE54 |
not referenced by any instruction |
$CE7D-$CE7D |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $CE7E |
not referenced by any instruction |
$CE8A-$CE8A |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $CE8B |
not referenced by any instruction |
$CF14-$CF14 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $CF15 |
not referenced by any instruction |
$CF57-$CF5A |
4 | ObjectPointerLowBytes ($CF57), ObjectPointerHighBytes ($CF59) |
two parallel 2-byte arrays of pointer bytes; entry i is the 16-bit address ($CF57+i) | (($CF59+i) << 8), i.e. $0301 and $0D80 |
lda $CF57,y at $CFA4, lda $CF59,y at $CF8F |
$CFD0-$CFD0 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $CFD1 |
not referenced by any instruction |
$CFEA-$CFEA |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $CFEB |
not referenced by any instruction |
$D008-$D009 |
2 | - | unreached code: two bytes that decode as LDA $6A,X |
not referenced by any instruction |
$D05D-$D06A |
14 | - | unreached code: the bytes decode as instructions throughout (INC $60; LDA $60; CMP #$14; BCS ...) and the CDL marks all 14 bytes as executed code. It is the fourth target of the dispatch table at $CD20 |
not referenced by any instruction |
$D091-$D0A9 |
25 | ObjectPointerThirdByteTable ($D0A6) |
$D091-$D0A4 = 20 bytes of small values in $68-$6D terminated by $00, read at run time (CDL) through an address the tracer cannot follow. $D0A6-$D0A8 = 3 x 8-bit bytes ($80 $C0 $40) loaded into the third pointer byte Zp02 |
lda $D0A6,y at $D0E7 |
$D248-$D248 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $D249 |
not referenced by any instruction |
$D251-$D251 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $D252 |
not referenced by any instruction |
$D281-$D281 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $D282 |
not referenced by any instruction |
$D391-$D392 |
2 | ObjectSlotIndexTable |
2 x 8-bit RAM slot indices ($00, $05) used as an X index into the two counters at $0361 and $0363 |
lda $D391,x at $D3A0 and $D421 |
$D48D-$D492 |
6 | ObjectXRangeLowBytes ($D48D), ObjectXRangeHighBytes ($D490) |
two parallel 3-byte arrays of 8-bit bounds: the low bytes ($2C $64 $AC) and the high bytes ($4C $94 $CC) of three X bands, [44,76), [100,148) and [172,204), tested against the object's X coordinate |
cmp $D48D,y at $D49F, cmp $D490,y at $D4A4 |
$D501-$D506 |
6 | ObjectDataPointerHighBytes ($D501), ObjectDataPointerLowBytes ($D505) |
two parallel arrays of pointer bytes: 4 high bytes ($01 $02 $04 $04, index = (value >> 2) & 3) and 2 low bytes ($0A $05, index = ZpD5), giving the 16-bit addresses $010A and $0205 |
lda $D501,y at $D51B, lda $D505,y at $D522 |
$D75E-$D7DD |
128 | ObjectSpeedTable ($D75E), IceBlockColumnXTable ($D762), SpriteTypeKeyTable ($D77F), SpriteTypeValueTable ($D785), SpriteTypePointerHighBytes ($D78B), SpriteTypePointerLowBytes ($D794), SpriteTypeAltValueTable ($D79D), PlayfieldLeftEdgeTable ($D7A3), PlayfieldRightEdgeTable ($D7AD), ObjectStepValueTable ($D7B7), ObjectStepAltValueTable ($D7BD), ObjectSpeedLimitTable ($D7C8), ObjectSpeedLimitAltTable ($D7D3) |
the playfield geometry and the sprite-type tables. $D762 = the 10 X positions of the ice-block columns ($02 $00 $18 $30 $48 $60 $78 $90 $A8 $C0, 24 pixels apart). $D7A3/$D7AD = the 10 left and right edges of the ten playfield rows ($20 $20 $20 $28 $28 $28 $30 $30 $30 $30 and $E0 $E0 $D8 $D8 $D8 $D0 $D0 $D0 $D0). $D77F = 6 key bytes searched linearly by the routine at $DDBF; $D785 and $D79D = the two 6-entry value tables the same search returns. $D78B/$D794 = 10 high and 10 low bytes of 16-bit pointers. $D7B7, $D7BD, $D7C8, $D7D3 = small step and speed values in $04-$10 |
lda $D75E,y at $D905, cmp $D7A3,y at $DA70, $DB5B, $DBD3, cmp $D7AD,y at $DA78, $DB60, $DBD8, lda $D7AD,y at $DA7D, lda $D7A3,y at $DA87, $DAE6, $DAEB, cmp $D7BD,y at $DB58 and $DB69, cmp $D7D3,y at $DB7A, adc $D7B7,y at $DB8A, cmp $D7C8,y at $DB9D, cmp $D7BC,y at $F8E8 and $F909, cmp $D77F,y at $DDC0 and $DEED, lda $D785,y at $DDC5, lda $D79D,y at $DEF2, lda $D762,y at $DBEA, $DD30, $DED0, adc $D762,y at $DFC0, lda $D78B,y at $E073 and $E7BC, lda $D794,y at $E06E and $E7C1 |
$D918-$D91B |
4 | ObjectXOffsetLowBytes ($D918), ObjectXOffsetHighBytes ($D91A) |
two parallel 2-byte arrays of signed offsets: the low bytes ($F8 $08) and the high bytes ($00 $05), added to a sprite's X coordinate |
lda $D918,x at $D96E, lda $D91A,x at $D934 |
$D966-$D966 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $D967 |
not referenced by any instruction |
$D9C4-$D9CB |
8 | SpriteAttributeMaskTable |
8 x 8-bit masks ($00 $40 $C0 $80 $40 $00 $80 $C0) OR-ed into a sprite's attribute byte after its low two bits have been masked out; the index is the sprite's own number |
ora $D9C4,x at $DA17 |
$DA97-$DA98 |
2 | EnemyPointerLowByteTable |
2 x 8-bit pointer low bytes ($FC, $0C), loaded into Zp00 after a call that tests whether the enemy is alive; the index is the enemy's state byte Zp62,x |
lda $DA97,y at $DAAD and $DDDC |
$DB4A-$DB4A |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $DB4B |
not referenced by any instruction |
$DC33-$DC33 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $DC34 |
not referenced by any instruction |
$DC8F-$DC96 |
8 | IceBlockPatternPointerTable |
4 x 16-bit little-endian pointers into the table at $D75E ($D76C, $D775, $D78A, $D793), copied into the zero-page pointer bytes by the loop at $DCFE |
lda $DC8F,y at $DCFE |
$DD0C-$DD15 |
10 | PlatformHeightThresholdTable |
10 x 8-bit height thresholds ($18 $18 $18 $16 $16 $16 $14 $14 $14 $14): used as the limit of a countdown, as the value written to $0303, and subtracted from $18 to give a distance |
lda $DD0C,x at $DD41, cmp $DD0C,x at $DD5C, sbc $DD0C,x at $DDA4 |
$DD8E-$DD8E |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $DD8F |
not referenced by any instruction |
$DE7A-$DE7A |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $DE7B |
not referenced by any instruction |
$DE8F-$DE8F |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $DE90 |
not referenced by any instruction |
$DEB8-$DEB8 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $DEB9 |
not referenced by any instruction |
$DEF6-$DFA4 |
175 | IceBlockRowXTable ($DEF6), IceBlockRowPointerLowBytes ($DEFA), IceBlockRowPointerHighBytes ($DEFB), IceBlockPositionTable ($DF1B) |
the level layout. $DEF6-$DEF9 = 4 X positions of the ice-block rows ($50 $80 $B0 $E0). $DEFA-$DEFF = two parallel 3-byte arrays of pointer bytes, giving $8167, $8970 and $8589. $DF1B-$DFA4 = 138 x 8-bit packed ice-block positions: the low five bits are the column (0-31) and the high nibble the row (0-15), read with and #$1F and four lsr a |
lda $DEF6,y at $E031, lda $DEFA,y at $DFED, lda $DEFB,y at $DFF2, lda $DF1B,x at $DFBA, $DFF8, $E0AA and lda $DF1B,y at $E01D, $E039, $E046 |
$E12B-$E12B |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $E12C |
not referenced by any instruction |
$E185-$E188 |
4 | ObjectVariantOffsetTable |
4 x 8-bit offsets ($28 $58 $88 $B8) selected by the difference of two zero-page counters, stored into ZpA8 |
lda $E185,x at $E1D9 |
$E273-$E276 |
4 | SpriteColumnXTable |
4 x 8-bit X positions ($00 $18 $30 $48, 24 pixels apart) used as an index into the sprite array at $02A0 |
lda $E273,x at $E27C, lda $E273,y at $E610 |
$E279-$E279 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $E27A |
not referenced by any instruction |
$E338-$E33B |
4 | SpriteRowYTable |
4 x 8-bit Y positions ($14 $2C $44 $5C, 24 pixels apart) used as an index into the sprite array at $02A0 |
lda $E338,x at $E348 |
$E382-$E4C1 |
320 | ObjectRowAttributeTable ($E382), ObjectParamByteTable1 ($E462), ObjectParamByteTable2 ($E472), ObjectParamByteTable3 ($E482), ObjectParamByteTable4 ($E492), ObjectPositionPairTable ($E4A2), ObjectPointerHighByteTable ($E4B2) |
a mixture. $E382-$E389 = 8 zero bytes read as a row-attribute table. $E38A-$E461 (216 bytes) is a run whose layout is not established: no instruction names an address inside it and the CDL marks only 11 of the 320 bytes as read. $E462-$E4A1 = four parallel 16-byte tables whose four bytes are assembled into one 32-bit value ($E462 << 24 | $E472 << 16 | $E482 << 8 | $E492) before being shifted right four bits by the bit-reader at $E74B. $E4A2-$E4B1 = 8 x 16-bit little-endian (X,Y) position pairs, read one byte at a time with a stride of two. $E4B2-$E4C1 = 16 x 8-bit bytes, of which the first ten are pointer high bytes |
lda $E382,x at $E4CE, lda $E4A2,x at $E4EF and $E67E, lda $E4A3,x at $E4F5 and $E683, lda $E4B2,x at $E668, lda $E4BB,x at $E6DE, lda $E4B7,x at $E6FE, lda $E462,y at $E740, lda $E472,y at $E73B, lda $E482,y at $E736, lda $E492,y at $E731 |
$E539-$E572 |
58 | ObjectTypeByteTable |
$E539-$E55A (34 bytes) = a table of 8-bit object-type parameters, read with an index that is the type's own slot number and whose low six bits are compared with a limit; $E55B-$E572 (24 bytes) = unreached code |
lda $E539,x at $E575 |
$E5C7-$E5C7 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $E5C8 |
not referenced by any instruction |
$E5FE-$E5FE |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $E5FF |
not referenced by any instruction |
$E727-$E72A |
4 | ObjectOffsetTable |
4 x 8-bit offsets ($D3 $8C $CD $8F), indexed by a value shifted right twice and masked to two bits |
lda $E727,x at $E775 |
$E778-$E778 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $E779 |
not referenced by any instruction |
$E77B-$E77B |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $E77C |
not referenced by any instruction |
$E78D-$E79C |
16 | SpriteBufferOffsetTable |
16 x 8-bit offsets into the sprite buffer at $0600 ($21 $4E $20 $4D $42 $42 $42 $42 $42 $48 $4E $9D $9D $9D $9D $9D), used as an X index when a sprite is written to the buffer |
ldx $E78D,y at $E81C, lda $E790,x at $E7E0 |
$E88C-$E998 |
269 | EnemySpriteTileTable ($E8C3), EnemySpritePaletteTable ($E8C7), EnemySpritePointerTable ($E8CB), EnemySpriteSpeedTable ($E8CF), EnemySpriteDataTable ($E8DE) |
the enemy sprite definitions. $E8C3, $E8C7, $E8CB and $E8CF are four parallel 4-byte tables (tile, palette, pointer byte and speed) read with the enemy's type as the index; $E8DE-$E8F3 is a 22-byte table of enemy data returned by the routine at $EA55. The rest of the block - $E88C-$E8C2 and $E8F4-$E998 - is not established: no instruction names an address inside it and the CDL never touched it |
lda $E8C3,x at $E9BA, lda $E8C7,x at $E9AC, lda $E8CB,x at $E9A0, lda $E8CF,x at $E9B3, lda $E8DE,y at $EA58 |
$E9CE-$EA48 |
123 | - | unreached code: the 123 bytes decode as 6502 instructions throughout (LDA $0360,Y; ADC $0365,X; ...) |
not referenced by any instruction |
$EA5C-$EA8D |
50 | - | unreached code: the 50 bytes decode as 6502 instructions throughout | not referenced by any instruction |
$EAA2-$EAFB |
90 | EnemySpriteDefinitionTable ($EAA2), EnemySpritePlane0Rows ($EABF), EnemySpritePlane1Rows ($EADD) |
the enemy graphics. $EAA2-$EABE = 29 x 8-bit offsets, one per enemy type, read with the enemy's type as the index. $EABF-$EADC and $EADD-$EAFB = two runs of 8x8 2bpp tile rows - the bytes are the bit patterns $55, $AA, $FF, $00, $22, $32, $42, $11, $21, $24 - read with the same index and used as the two bit planes of the enemy's sprite |
lda $EAA2,x at $EB9C and $EC48, lda $EABF,y at $EB03, lda $EADD,y at $EB0E |
$EB14-$EB2D |
26 | - | unreferenced data: 26 x 8-bit values in $01-$08 (fourteen of them are $04), the shape of a per-enemy-type speed or step table. No instruction in this dump names an address inside the block and the CDL read only four of the bytes, so the index and the units are not established |
not referenced by any instruction |
$EB55-$EB55 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $EB56 |
not referenced by any instruction |
$EB61-$EB61 |
1 | - | single $24 byte: the opcode of a two-byte BIT zp whose operand byte is the first byte of the routine at $EB62 |
not referenced by any instruction |
$ECB7-$ECBE |
8 | - | unreached code: two complete JSR instructions (JSR $30F0, JSR $1DC0) |
not referenced by any instruction |
$ECE9-$ECE9 |
1 | - | single $85 byte: the opcode of a two-byte STA zp whose operand byte is the first byte of the routine at $ECEA |
not referenced by any instruction |
$ED09-$ED24 |
28 | - | unreached code: the 28 bytes decode as 6502 instructions throughout (LDY $43; STY $D0; ...) |
not referenced by any instruction |
$ED68-$EDBE |
87 | - | unreached code: the bytes decode as 6502 instructions throughout and the CDL marks 77 of the 87 bytes as executed code | not referenced by any instruction |
$EDD0-$EDD4 |
5 | - | unreached code: the bytes decode as LDA $5A; BIT $5B; LDA $5B |
not referenced by any instruction |
$EDE6-$EE0C |
39 | EnemyBehaviourParameterTable ($EDE6), EnemyAttackAngleTable ($EDED), EnemySpeedTable ($EDF1) |
the enemy behaviour parameters. $EDE6-$EE0C is one run of 39 parameter bytes read from four overlapping bases: $EDED (8 x 8-bit attack timers, $68 $98 $C8 $F0 $18 $20 $28 $20, compared against an enemy's timer), $EDF1 (12 x 8-bit values, indexed by a running counter plus a per-enemy offset), $EDFD (9 x 8-bit values stored into the per-enemy field at $03DD) and $EE00 (13 x 8-bit values added to the enemy's Y position) |
lda $EDFD,y at $EEB5, lda $EDED,y at $EEDD, lda $EE00,y at $EF26, lda $EDF1,y at $EF96 |
$EFE2-$EFEB |
10 | ObjectSpawnXTable |
10 x 8-bit X positions; the eight entries at $EFE4-$EFEB ($30 $40 $40 $50 $60 $70 $80 $90, 16 pixels apart) are read with an index masked to three bits and stored into the per-enemy field at $03A6; $EFE2-$EFE3 are unreferenced |
lda $EFE4,y at $F0B1 |
$F02F-$F03A |
12 | SoundDurationTable |
12 x 8-bit values in $01-$07, read with an index computed from a sound value and the pointer byte Zp00; the code special-cases the twelfth entry against $07 |
lda $F02F,y at $F063 |
$F107-$F10A |
4 | - | unreferenced data: four bytes ($10 $0E $0C $0C) that look like a short step or speed table, but no instruction in this dump names an address inside the block and the CDL never touched it, so the index and the units are not established |
not referenced by any instruction |
$F149-$F19D |
85 | - | unreached code: the bytes decode as instructions (the head uses the undocumented $CF opcode), and the CDL never touched the block |
not referenced by any instruction |
$F1AC-$F2EB |
320 | MusicSequenceData ($F1AC), MusicNoteDurationTable ($F267), MusicNoteParameterTable ($F291), MusicChannelParameterTable ($F2E4) |
the music data. $F267-$F28F = 41 x 8-bit note values in a rising sequence ($01 ... $2E, then $00); $F291-$F2B9 = 41 x 8-bit per-note parameters; $F2E4-$F2EB = 8 x 8-bit per-channel parameters, indexed by the channel number masked to three bits. $F1AC-$F266 and $F2BA-$F2E3 are the rest of the sequence data; their finer layout is not established |
cmp $F22F,x at $F33A, lda $F238,x at $F34E, lda $F25E,x at $F34A, lda $F2BA,y at $F3D5, lda $F267,y at $F3DD, lda $F291,y at $F3E4, lda $F2E4,x at $F3AB |
$F3C5-$F3C5 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $F3C6 |
not referenced by any instruction |
$F45A-$F45A |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $F45B |
not referenced by any instruction |
$F466-$F503 |
158 | MusicChannelNoteTable ($F46C) |
$F466-$F46B = 6 bytes whose layout is not established; $F46C-$F503 = a table of music-channel data, indexed by the channel number Zp6A,x and stored into the per-channel field Zp37,x. The rest of the block decodes as instructions and the CDL never touched it, so the table/data boundary inside the block is not established |
lda $F46C,y at $F506 |
$F51C-$F523 |
8 | ScreenBufferInitData |
$F51C-$F51D = 2 unreferenced bytes; $F51E-$F523 = 6 x 8-bit bytes copied into the nametable-copy buffer at $0400 by the loop at $F52D |
lda $F51E,x at $F52D |
$F538-$F563 |
44 | MusicChannelInitBytes |
$F538-$F53A = 3 x 8-bit bytes copied into the sprite buffer at $0301; $F53B-$F563 is unreached code (the CDL marks $F53E as a jump target) |
lda $F538,y at $F566 |
$F582-$F585 |
4 | - | unreferenced data: 4 bytes ($00 $05 $00 $0E) of which the two at $F583-$F584 are added to $48 to form a value stored in the sprite buffer; the index and the units are not established |
adc $F583,x at $F592 |
$F5C9-$F62F |
103 | MusicNoteSequenceTable ($F5D3), MusicChannelEnvelopeTable ($F5F9), MusicChannelInitTable ($F609) |
the per-channel music parameters. $F5D3-$F5F8 = 38 x 8-bit note/frequency bytes; $F5F9-$F608 = 16 x 8-bit envelope bytes; $F609-$F614 = 6 x 8-bit initialisation bytes. $F5C9-$F5D2 and $F615-$F62F are unreached code |
lda $F5D3,y at $F660, lda $F5F9,x at $F693, lda $F609,y at $F671 |
$F63B-$F64B |
17 | - | unreached code: the bytes decode as instructions throughout and the CDL marks 13 of the 17 bytes as executed code | not referenced by any instruction |
$F67E-$F690 |
19 | - | unreached code: the bytes decode as instructions throughout and the CDL marks all 19 bytes as executed code | not referenced by any instruction |
$F6EF-$F71C |
46 | - | unreached code: the bytes decode as instructions throughout (LDY #$30; CPY #$A2; LDA #$00; STA $91,X; ...) |
not referenced by any instruction |
$F730-$F736 |
7 | SoundEffectPointerLowBytes ($F730), SoundEffectTileTable ($F733) |
two parallel 3-byte arrays: $F730-$F732 ($3E $46 $46) are pointer low bytes loaded into Zp02; $F733-$F735 ($50 $51 $4E) are tile bytes written into the sprite array at $0241 |
lda $F730,y at $F751, lda $F733,x at $F77D |
$F7B8-$F80B |
84 | ObjectCounterInitTable ($F7B8), ObjectBehaviourStepTable ($F7BC), MusicChannelInitValues ($F7E8), ObjectTypeCountTable ($F7EC) |
the object behaviour table. $F7B8-$F7BB = 4 x 8-bit initial counter values, stored into $03BC. $F7BC-$F7DF = 36 x 8-bit behaviour bytes in four groups of eight, each group terminated by $FF; the counter $03BC indexes them and bit 2 and the value $FF are tested. $F7E8-$F7EB = 4 x 8-bit values ($10 $F0 $10 $F0). $F7EC-$F803 = 24 x 8-bit counts in $00-$03 |
lda $F7B8,y at $F81A, lda $F7BC,y at $F8E8 and $F909, lda $F7E8,y at $F815, lda $F7EC,y at $F8AF |
$F8CA-$F8CA |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $F8CB |
not referenced by any instruction |
$F910-$F910 |
1 | - | single $2C byte: the opcode of a BIT abs whose operand bytes are the first two bytes of the routine at $F911 |
not referenced by any instruction |
$F91C-$F91D |
2 | - | unreferenced data: two bytes of $FF. No instruction in this dump names an address inside the block and the CDL never touched it |
not referenced by any instruction |
$F993-$F9AA |
24 | NoteControlTable ($F993), NotePeriodTable ($F99F) |
two parallel 12-byte tables of the music engine's note data. $F99F-$F9AA = the 12 note periods, written straight into the APU pulse-1 timer ($4002/$4003); $F993-$F99E = 12 control bytes, used as an X index by the routine the note handler jumps to |
lda $F99F,y at $F9B6, ldx $F993,y at $F9C1 |
$FA63-$FA63 |
1 | - | a single $1A byte that the CDL marks as read as data at run time; no instruction in this dump names an address inside the block and the layout of the one byte is not established |
not referenced by any instruction |
$FB3B-$FB70 |
54 | SoundEffectParameterTable ($FB3B), SoundEffectChannelOffsetTable ($FB4B), NoiseEffectParameterTable ($FB52), NoiseEffectChannelOffsetTable ($FB62), NoiseEffectLengthTable ($FB6A), NoiseEffectAltOffsetTable ($FB6E) |
the sound-effect parameter tables. $FB3B-$FB4A = 16 x 8-bit parameters indexed by the sound id masked to four bits; $FB4B-$FB52 = 8 x 8-bit channel offsets indexed by the sound id shifted right three; $FB52-$FB61 = 16 x 8-bit noise parameters; $FB62-$FB69 = 8 x 8-bit noise channel offsets; $FB6A-$FB6D = 4 x 8-bit noise lengths; $FB6E-$FB70 = 3 x 8-bit offsets. All of them feed the routine at $FB8C, which writes the APU noise registers |
ldx $FB4B,y at $FB80, lda $FB3B,y at $FB89, ldx $FB62,y at $FBD0, lda $FB52,y at $FBD6, ldx $FB6E,y at $FBF0, lda $FB6A,y at $FBF6 |
$FD22-$FFFF |
734 | SoundEngineData ($FD22), ApuPulse2ControlTable ($FFDB), CpuVectors ($FFFA) |
the fixed data area of the sound engine plus the CPU vectors. $FD22-$FD29 = 8 x 8-bit offsets into the block, one per bit count: the routine at $FC1B reads the offset with lda $FD21,y (the byte before the block is the RTS of the routine at $FD21, so the offsets are the block's own first eight bytes) and then reads a 6-byte record - five bytes into the zero page and one into $0705 - that describes a sprite. $FD2A-$FFDA = the sound engine's data blob: the CDL marks 618 of the 734 bytes as read at run time, but the individual tables inside it are not separated by the code, so its layout is not established. $FFDB-$FFF8 = 30 x 8-bit APU pulse-2 control bytes ($50-$57, i.e. the eight duty settings at a constant volume of 1) written to $4004. $FFFA-$FFFF = the three CPU vectors (NMI $C076, RESET $C014, IRQ $FFF0) |
lda $FD21,y at $FC1B, lda $FD22,y at $FC1F, lda $FD23,y at $FC24, lda $FD24,y at $FC29, lda $FD25,y at $FC2E, lda $FD26,y at $FC33, lda $FD27,y at $FC38, lda $FFD9,y at $FCBE |
Notes on the blocks that are not tables
- Thirty-four one-byte regions hold a single opcode byte that the
CPU really executes: thirty-one of them hold
$2C(BIT abs),$EB61holds$24(BIT zp),$ECE9holds$85(STA zp) and$FA63holds$1A, which the CDL marks as data. The tracer's split could not attribute the byte, so it is emitted as a data region; the instruction that follows it starts at the same address in both readings, so no byte is misplaced and the build is unaffected. Mesen's own disassembler confirms the reading ($C5ECisBIT $00A9). - Twenty-three regions hold code the tracer could not reach, in
whole or in part. They are
listed above with the reason: most of them are the bodies of the
routines the dispatch tables at
$C440and$CD20point at, and the Mesen CDL capture shows the CPU executing them. Seeding the tracer at the first byte of each would turn them back into routines. - Three regions are data the ROM does not pin down:
$C5A1-$C5A6(6 bytes),$EB14-$EB2D(26 bytes) and$F107-$F10A(4 bytes). Their byte patterns are those of small per-type value tables, but no instruction in this dump names an address inside them and the CDL only read a handful of bytes, so the index and the units are not established. They are left unnamed on purpose. - Two large runs inside named blocks are not established either:
$E38A-$E461(216 bytes, inside the$E382-$E4C1block) and the sound-engine blob$FD2A-$FFDA(691 bytes, inside the$FD22-$FFFFblock). Both are recorded with their ROM provenance rather than given a speculative name. - The
ApuPulse2ControlTableat$FFDBis not ASCII text, even though$50-$57are the codes forPtoW: the values are written to the APU pulse-2 control register at$4004, where$50-$57are the eight duty-cycle settings with a constant volume of 1.
Open work
- The routine names are still
SubC<addr>for everything except the vector entries and a handful ofUpdate*/Init*routines; the game's roles for the rest are not established from the code alone. - The zero-page aliases in
locals.incare mostly the generatedZpXXnames; the roles are not proven from the code alone. - The layout of the 216-byte run
$E38A-$E461(inside the$E382-$E4C1block) and of the 689-byte sound-engine blob$FD2A-$FFDA(inside the$FD22-$FFFFblock) is not established. Both are recorded with their ROM provenance in the inventory rather than given a speculative name. - Three small blocks -
$C5A1-$C5A6(6 bytes),$EB14-$EB2D(26 bytes) and$F107-$F10A(4 bytes) - look like per-type value tables, but no instruction in this dump names an address inside them and the Code Data Logger only read a handful of bytes, so their index and units are not established. They are left unnamed on purpose. - Twenty-three of the data blocks are code the tracer could not
reach. They stay
.byterows; seeding the tracer at the first byte of each would turn them back into routines. - The 34 one-byte blocks hold an opcode byte that the CPU really
executes (
$2C=BIT absin 31 of them). The tracer's split could not attribute the byte, so it is emitted as data; the instruction that follows it starts at the same address either way, and no byte is misplaced.
Entry-point naming (2026-10-21)
Every jsr/jmp target that carried an address-derived SubCxxxx name
was reviewed against the routine it points at, the code that calls it and
the RAM fields it touches. The same pass was applied to the (JE)
variant, whose PRG is byte-identical to this one, so the two prg.s
files stay identical.
| count | |
|---|---|
| Address-derived entry points before | 191 |
| Entry points now carrying a semantic name | 138 |
| Entry points still address-derived | 53 |
The names now in prg.s cover:
- The sound engine —
UpdateSoundEngine,UpdateSoundPulse1,UpdateSoundPulse2,UpdateSoundNoise,SetPulse1Tone,SetPulse2Tone,SetPulse1Timbre,SetPulse1TimbreLow,SetPulse1TimbreAlt,SetPulse2Timbre,GetSoundEngineValue,ResetPulse1Voice,SilencePulse1,CheckSoundIdle,UpdateSoundForObject. - The objects on the ice —
UpdateObject,UpdateObjectByType,UpdateObjectSprite,UpdateObjectAndSprite,SetObjectTile,SetObjectTileAndAttribute,SetObjectTileAlt,SetObjectType,SetObjectPosition,SetObjectDirection,SetObjectColour,SetObjectTileIndex,SetObjectSpriteIndex,SetObjectFlagsPointer,GetObjectFlags,GetObjectTileOffset,GetObjectTileOffsetAlt,GetObjectTileOffsetC,GetObjectAttributeOffset,GetObjectSpriteTile,GetObjectSpritePointer,GetObjectBehaviour,GetObjectCounter,AddObjectCounter,AddObjectCounterAlt,AdvanceObjectCounter,TickObjectCounter,TickObjectTimers,TickObjectDelay,TickObjectAnimation,GetObjectAnimationState,GetObjectAnimationMask,ResetObjectState,InitObjectState,InitObjectSprite,DrawObjectSprite,WriteObjectToOam,WriteObjectToOamAlt,LoadObjectSprite,SpawnObject,ClampObjectIndex. - The player and the enemies —
MovePlayer,MoveEnemy,UpdatePlayerObject,UpdateSecondPlayerObject,UpdatePlayerObjectAlt,UpdatePlayerSprites,UpdatePlayerSprite,UpdatePlayerSpriteAlt,UpdatePlayerMovement,CheckPlayerCollision,CheckObjectCollision,CheckObjectTile,CheckObjectInRange,CheckObjectOnScreen,CheckObjectOnScreenAlt,CheckObjectFlags. - The board and the scrolling —
UpdateLevelScroll,ScrollLevelLeft,ScrollLevelRight,ScrollLevelIfNeeded,CheckScrollPosition,GetScrollRow,AdvanceScrollColumn,UpdateBoardState,ResetBoardState,SetObjectMapEntry,WriteObjectMapEntry,GetObjectMapEntry,PlaceObjectOnBoard,ConvertObjectPosition,SplitObjectPosition,ComputeObjectRow,ComputeObjectHeight,ComputeObjectDistance,ComputeObjectReach,GetObjectReach,MoveObject,MoveObjectUp,MoveObjectUpStep,MoveObjectAndPlaySound,AddObjectXOffset,AddObjectOffset,ToggleObjectFlag,SaveObjectPointer,UpdateObjectAnimation,StartObjectAnimation. - Small helpers —
Negate,GetRandomIndex,CompareRandomPair,CheckRandomPair,GetTableIndex,SetInputState,ReadPlayerStat,UpdateSprites,UpdateSpritePosition,ReadMovementTable,ReadBehaviourTable,CheckStartButton,CheckExpansionInput,TickGameTimer.
Residue — 53 entry points remain address-derived. They are the one-instruction fragments of the object's state machine: helpers that load a constant into X or Y, branch on a flag the dump does not explain, or select one of the game's per-player slots. The dump does not reveal a role that would distinguish them from their neighbours, so they keep their address-derived names. They are
SubCCE88, SubCCEDB, SubCD021, SubCD0C5, SubCD111, SubCD1E5,
SubCD1F9, SubCD2F9, SubCD421, SubCD463, SubCD493, SubCD507,
SubCD6E0, SubCD724, SubCD890, SubCD9AD, SubCD9CC, SubCDA4B,
SubCDAB2, SubCDB1D, SubCDBB0, SubCDBB4, SubCDDBD, SubCDEEA,
SubCE002, SubCE05E, SubCE277, SubCE27A, SubCE29A, SubCE321,
SubCE33C, SubCE523, SubCE63D, SubCE79D, SubCEA4A, SubCEB2E,
SubCEB5F, SubCEC51, SubCECBF, SubCED63, SubCEE0D, SubCEEA2,
SubCEF06, SubCEF42, SubCEF9A, SubCF10B, SubCF13B, SubCF35B,
SubCF3BD, SubCF564, SubCF71D, SubCF8DB, SubCF964.