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tdkpin/original/MECHANICS_PROGRESS.md
T
ddidderr 9e74745fde docs(testing): record live original comparison
Document the Wine-backed original start and charged-launch captures, the matching deterministic Rust states, and the remaining boundary that a chosen claw terminal was not forced in the live original.

Test Plan:
- Launch original/TDKPIN.EXE with Wine 11.15 staging
- Send keypad plus, hold Down for 1.1 seconds, release, and inspect captures
- Compare original started state with Rust launcher step zero
- git diff --cached --check
2026-08-22 18:55:41 +02:00

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Markdown

# Mechanics reconstruction progress
This ledger scopes the current reverse-engineering pass to the claw and
flippers. The preserved executable is the authority; `TDKPIN_GHIDRA_RAW.c`
remains immutable raw evidence, while `TDKPIN_MECHANICS_RESTORED.c` carries
reviewed names and control flow.
Target: `TDKPIN.EXE` SHA-256
`a9022f1894e3e6e21fc42e8f6c932f7c549ca77f63aaa0c488bb9d55d9d0174c`.
## Function inventory
| Address | Raw name | Restored role | Status |
| --- | --- | --- | --- |
| `1000:638e` | `FUN_1000_638e` | key-release flag updates | reviewed |
| `1000:6bf8` | `FUN_1000_6bf8` | key-press flag updates | reviewed |
| `1000:7ed9` | `FUN_1000_7ed9` | flipper collision movement and sound | reviewed; inner fixed-point geometry still raw |
| `1000:8b0d` | `FUN_1000_8b0d` | flipper bitmap/collider movement | reviewed; inner fixed-point geometry still raw |
| `1000:99f0` | `FUN_1000_99f0` | binary flipper transition state machine | restored |
| `1000:c79c` | `FUN_1000_c79c` | collision dispatch, including claw object `0x59` | claw branch restored |
| `1000:eab1` | exported ordinal 10 | timer tick, claw release and return | claw branch restored |
| `1008:0002` | `FUN_1008_0002` | sound-enabled dispatch | restored |
| `1008:0e08` | `FUN_1008_0e08` | claw background restore and sprite slicing | restored |
Inventory coverage is 9/9 functions inspected for this mechanism pass. This is
not a claim that all instructions in the two large physics functions have been
renamed.
## Proven behavior now available to the Rust port
- Left Control (scan `0x1d`) and keypad Enter (scan `0x1c`) set input flags;
the timer changes each flipper position only between 0 and 1.
- Every flipper movement edge, including return, invokes sound number 21,
Win16 WAVE resource 2021.
- Claw collision object `0x59` suspends the ball, zeros its live motion,
disables collision records 12 through 20, and selects terminal frame 1, 6,
7, or 18.
- The claw advances exactly one frame per timer tick to its terminal, releases
the ball, then advances one frame per tick back to frame 10 before clearing
the overlay and restoring collision records 12 through 20.
- Resource 900 is sliced into 100x74 frames, nine columns by four rows. The
destination is `(238,47)`; closing rows begin at source y=0 and opening rows
at source y=148.
- Claw capture/contact uses sound 2015; release uses sound 2016.
- The release-coordinate projection is `(raw + 500) / 1000` for rendering;
decoded physics centers are `(258,78)`, `(270,94)`, `(275,97)`, and
`(325,92)` for the four selectable terminal frames.
- The speed scalar is 3800 millipixels per tick. Its Borland Real48 direction
constants are decoded for all release cases in the readable C companion.
## Explicit pending evidence
- Differentially verify the recovered 10/20/30/40/50 ms timer choices against
live original captures; the Rust port intentionally uses the default 30 ms
claw cadence independently of render rate.
- Transcribe the full fixed-point flipper impulse calculation, then compare it
with the Rust floating-point collision response.
- Force a chosen claw terminal in the live original and compare its complete
frame/trajectory sequence with the deterministic Rust trace.
Those items are intentionally not counted as semantic parity. The readable
C file preserves their raw constants and labels the unresolved conversion so a
later implementation cannot silently turn an estimate into claimed evidence.
## Runtime comparison on 2026-08-22
Wine 11.15 (staging) ran the preserved 16-bit NE executable from this tree.
Keypad `+` was sent to the real window and produced the one-player started
state. Down was then held for 1.1 seconds and released; captures confirmed that
the original plunger advances while held and launches only on release.
The Rust validation mode captured the corresponding started and half-charge
states plus closing and release frames for claw terminal 6. The original claw
was not forced into a chosen terminal during the live session, so its claw
parity evidence remains the decoded `1000:c79c`/`1000:eab1` control flow,
millipixel/Real48 constants, sprite sheet, and deterministic Rust traces rather
than a claimed live trajectory comparison.