The port kept 60 on a stated constraint: the transition quad is declared
black for 12 units, measured at 0.14-0.30 s, giving 40-86 units/s, so 60 is
in and 120 is out. Attempted to refute it, and it does not hold.
Two reasons, either sufficient.
The low end is the instrument's floor. title-plate-delay-measured.md says
of that number, in its own words, "at a sampling resolution (0.125 s) that
cannot do better". 0.14 s IS one sample. At 120 units/s, 12 units is
0.100 s, which a 0.125 s sampler reports as roughly 0.14 s -- exactly the
value read as excluding it. The 86 units/s upper limit is an artefact of
dividing by a floored duration.
And a wall-clock duration off Canary is not independent of the unknown.
Apparent units/s = true units/s x speed factor, and the speed factor is
precisely what makes the three routes disagree. The bracket says "if Canary
ran at real time, 40-86" and whether it did is the question.
What survives is the declared side, and it is a disc fact worth keeping:
the transition opens over 12 units, independently confirmed as 6 frames by
screen-transitions.md's 255/6-per-frame ramp. That leg has no wall clock in
it and is real evidence -- for units per FRAME, which was never in dispute.
This does not argue for 120. Nothing supports 120 either. It removes a
reason for excluding it, and my position is unchanged: the value is
authored until the content-hash experiment runs.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Jc4pciRArGHfxGGhEbwp5t
eeb4473b4f