Movie (from power-on) which gets the door clip in level 2. Base file for further testing, cf. also here and here. The relevant memory addresses here are:
0x00512C (4 bytes) in combined WRAM, specifically the byte 0x00512F which is the bool that decides whether the door is open or not.
The crucial thing here seems the shot (2 A-presses) around frame 7815. It can happen as early as frame 7812 (first non-black frame into the room: 7801), here are the outcomes (when deleting or inserting frames before the U+A inputs):
| Shot starts on frame | value of 0x00512C after breaking box 1 | value of 0x00512C after breaking box 2 |
|---|---|---|
| 7812 | 00000003 | 00010003 |
| 7813 | 00000003 | 00010003 |
| 7814 | 00000003 | 00010003 |
| 7815 | 01000003 | 01010003 |
| 7816 | 01000003 | 01010003 |
| 7817 | 01000003 | 01010003 |
| 7818 | 01000003 | 01010003 |
| 7819 | 00010003 | 00010003 |
| 7820 | (death) |
Further observations:
- When changing the shot at 7709 (e.g., deleting the 7709 A-press and adding an A-press at 7712) then everything breaks
- The same is not true for the movement: deleting the L-presses on frames 7709-7713 does not change anything. Also deleting 7714 breaks things, but only because the shot at 7815 does not happen; if that shot is shifted to 7817+7818, then the clip still works