OATHKEEPERGRAPHING
FUNCTION GRAPHRAD
FUNCTIONS OF x GRAPH → DRAW
GRAPH LIMITS GRAPH → APPLY
Open standalone calculator
Download calculator (ZIP)
On Windows, extract the ZIP and double-click Calculator.html.
Power on
KnightOS
Power on
OATHKEEPERKNIGHTOS
OPEN BY DESIGN
Inside the instrument.
Oathkeeper pairs a scientific calculator with an emulator for the included classic graphing-calculator software. The included programs run on the open-source KnightOS firmware. Both systems run in your browser.
With your approval, we can build on proven open-source components and save you the time and cost of recreating them. Here we integrated the z80e emulator and KnightOS with our calculator, then tested game controls, program switching and the return to the graphing workspace.
Scientific and symbolic mathematics
math.js handles numerical calculations, units, complex numbers, matrices and statistics. Nerdamer supplies the optional exact algebra and calculus tools.
Expressions, history and memory stay in your browser. MATH opens additional tools and MODE selects the engine. The Oathkeeper mathematics workspace is separate from the KnightOS guest.
Software for real calculator hardware
z80e recreates the calculator’s processor and screen so original community programs can run. The openly licensed KnightOS operating system runs inside it. The keys you press reach the original program.
The guest uses its own operating system and mathematics. It does not call the modern math engines.
Open-source foundations
AI can find suitable open-source foundations, inspect their licenses and interfaces, and adapt them into a complete application. Reuse directs effort toward the missing user experience instead of rebuilding a math engine or CPU emulator.
Upstream authors retain their credit. This release adds the browser interface, integration, controls, examples, and packaging.
A closer look at the architecture
The modern math libraries run in a separate browser worker with a calculation time limit. The emulated guest executes Z80 assembly instructions, receives key-down and key-up events, and supplies the LCD pixels. Guest variables, arithmetic, and files remain inside KnightOS; there is no hidden bridge to math.js or Nerdamer.
Credits, licenses & release notes
Oathkeeper Graphing Calculator. Browser interface, controls and integration developed with AI.
math.js 15.2.0 — Jos de Jong and contributors · Apache-2.0. Nerdamer 1.1.13 — Martin Donk and contributors · MIT. z80e and OpenTI bindings — KnightOS Group · MIT. KnightOS kernel and core applications — KnightOS Group · MIT.
Read all license notices · Build & use guide
Modern numerical results normally use floating-point arithmetic; use bignumber(...) for decimal precision or Exact & symbolic for rational algebra. Function graphs are sampled views, not proofs.