id: BL-042
title: The same walk left, one frame later
shows: As BL-041 but LEFT is held on frames 371-392 (the input is one frame later).
inputs: BL-042.inputs
frames: 800
rom_sha1: 0940fea7f04cdb6d4b90c5ad1a7e344e68f6dbb1
trace_sha256: e4f5edf7425f39a65d3c187fc1b549ad8e581d70e2525952186dd7e1ea9c782c
trace_bytes: 240016
observations:
  Frames are counted from power-on (frame 0). Memory bytes are named by their address; the meanings are working labels
  (Stages C6 and C7, docs\CONTROLS.md and docs\CAPTURES.md), not yet confirmed (Phase F). Every number below was read from the trace.
  - Game Reset on frame 240 starts a game; play begins on frame 367 (the start tune takes 127 frames).
  - Joystick on frames 371-392: LEFT.
  - Pac-Man starts at (76,60).
  - Ghost start places at frame 367 (play begins): ghost 0 (76,30); ghost 1 (76,30); ghost 2 (76,30); ghost 3 (76,30).
  - Ghost 0: first change of place on frame 368 (1 frames after play began); 41 changes in all, on frames whose number mod 4 is 0 (41 times); changes of 1: 29, 2: 12 pixels (count); frames between changes: 4: 40.
  - Ghost 1: first change of place on frame 369 (2 frames after play began); 41 changes in all, on frames whose number mod 4 is 1 (41 times); changes of 1: 21, 2: 20 pixels (count); frames between changes: 4: 40.
  - Ghost 2: first change of place on frame 370 (3 frames after play began); 41 changes in all, on frames whose number mod 4 is 2 (41 times); changes of 1: 29, 2: 12 pixels (count); frames between changes: 4: 40.
  - Ghost 3: first change of place on frame 371 (4 frames after play began); 40 changes in all, on frames whose number mod 4 is 3 (40 times); changes of 1: 20, 2: 20 pixels (count); frames between changes: 4: 39.
  - 60 frames after play began (frame 427): Pac-Man (64,60); ghosts 0:(88,37), 1:(88,40), 2:(88,37), 3:(88,40).
  - 120 frames after play began (frame 487): Pac-Man (64,60); ghosts 0:(71,40), 1:(65,40), 2:(71,40), 3:(65,40).
  - Frame 531 (164 frames after play began): the pause flag is set (Pac-Man is caught). Distance of each ghost from Pac-Man in pixels (x plus y): ghost 0: 13, ghost 1: 35, ghost 2: 13, ghost 3: 5.
  - Compared with BL-038 frame by frame from the start of play (164 frames, up to the earlier catch): the first difference in a ghost place is 126 frames after play began (ghost 1: (64,38) here, (64,42) in BL-038).
  - Ghost routes compared with BL-038 by the places each ghost visits, timing ignored (up to the earlier catch): ghost 0: the same 42 places in the same order; ghost 1: first different place is number 32; ghost 2: the same 42 places in the same order; ghost 3: first different place is number 38.
  - How to check it against the real game: switch on, press Game Reset, then do what the list of joystick moves says; watch the ghosts leave the box and come at Pac-Man.
