OATHKEEPER GRAPHING CALCULATOR — IMPLEMENTATION AND VERIFICATION

This edition includes a 35:73 body, 3:2 LCD, left-hand directional control,
and a single shared hardware map. ON is an independent host power key; the
remaining 49 guest scan codes match the bundled KnightOS kernel definitions.
The same 401 [x,y] samples feed the modern graph, trace and value table. The
renderer honors the math worker’s separate list of discontinuity intervals.
Run proof/keypad-check.cjs and proof/worker-boundaries.cjs from the full source
directory. The individual boundary results are in proof/worker-boundaries.json.
The guest-input regression exercises the shipped adapter against a keyboard-port
fixture. It covers simultaneous arrows/WASD, Ctrl/Shift, Enter/Space, keyboard
repeat, modifier shortcuts, blur, power-off and ordinary editor text entry.

Earlier runtime observations for the retained mathematical engines, emulator
and guest image follow. They describe the versions and journeys tested.

Modern mathematics
18 checks execute the actual bundled math worker: precedence, postfix percent,
degree/radian trigonometry, unit conversion, matrix determinant, complex numbers,
statistics, decimal precision, exact fractions, equation roots, differentiation,
integration, invalid/undefined expressions and 401-point function sampling.
All passed. Live browser interaction also confirmed arithmetic 14, percentage 36,
10.08 cm unit conversion, determinant −2, sin(30 degrees)=0.5, roots [2,−2], graph,
error recovery with prior result preserved, editable history recall without
re-evaluation, angle-change staleness, keyboard Enter and memory 4→mem*2=8.
History and expression state survived reload. Free source download completed
through the visible link without a sign-in or payment gate.

Authentic calculator software
The guest is a source-built KnightOS image for the included emulator. The current release repacks the retained kernel, programs and icons
from the previous source-built release. Phoenix, Periodic Table, Calendar,
CalcSys and Text Editor launch in the bundled emulator. See the guest build
report and proof/guest-release-check.py in the full source download.
Earlier browser checks confirmed Phoenix enemies and projectiles, Periodic
navigation to Lithium and 'hello world' entry in the original bed editor.

A narrow CPU repair
The historical compiled emulator incorrectly read the subtraction flag instead
of the sign flag for positive/negative conditions. The original artifact and
reproducible two-shift repair are included. All 6,144 cases passed: each of eight
conditional JP/CALL/RET instructions across all 256 possible flag bytes. This is
focused regression coverage, not a claim to exhaustively certify the whole CPU.

Browser integration
The static application ran under the existing same-origin CSP with no inline
script, unsafe-eval allowance, remote script CDN or proprietary calculator ROM.
The old runtime needs explicit completion after asynchronous memory-file loading
and its original logging callbacks; the adapter supplies both. Short key-down
and key-up events receive enough real CPU cycles for the guest scanner, credited
against scheduled runtime time.
The managed browser delivered only five animation frames over 4,082 ms, with a
maximum 1,016.5 ms gap, while CPU work totaled 179.9 ms. Separating the 25 ms CPU clock
from LCD drawing restored full game progress in the affected check. Catch-up is
capped at 250 ms; long background intervals are discarded when paused. Performance
and display smoothness still depend on the browser/device.

Scope
This release is a standalone browser adaptation of the Oathkeeper calculator behavior.
It does not claim completion or publication of native OathkeeperOS. The modern math
engines and the guest OS are separate: guest programs do not call the modern CAS.
Other calculator models, other imported binaries and link multiplayer
are not qualified. No physical phone/tablet or examination approval is claimed.
Guest files, including files saved inside the guest, are temporary for the current
session; restart restores the original image. Graphs are sampled visualizations,
not proofs. Numerical precision and symbolic-domain assumptions follow the
selected engines; the included examples and notices explain the available modes.

Independent visual review
The final revision passed desktop and constrained-layout review. In the 390 px
iframe, content width and scroll width were both 375 px; graph axes stayed readable
and correctly labeled both 0–100 and 0–1000. Essential guest soft keys measured
44 px high with 12 px labels. Input focus, result/error/stale states, SVG icons,
credits, source links and hub navigation were observed. This fixture does not
substitute for testing a physical phone or tablet.
