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RCX Internals (Kekoa Proudfoot)
The canonical reverse-engineering of the RCX: serial/IR protocol, the byte-code interpreter, and the full opcode set. The reference that NQC, brickOS, leJOS and others built on.
What it documents
- RCX hardware: Hitachi H8 MCU, 32K external RAM, 3 motors / 3 sensors / IR serial port.
- The RCX IR protocol framing (header
55 FF 00, byte+complement pairs, checksum) and the toggle bit. - Every opcode (alive/ping, set motor, play sound, poll value, download program/firmware, messages…).
Used alongside NQC · BrickCC and the crynwr LEGO Mindstorms Internals mirror (see Link directory).
Links
- Main: graphics.stanford.edu/~kekoa/rcx
- Opcode reference: graphics.stanford.edu/~kekoa/rcx/opcodes.html (mirror: mralligator.com/rcx/opcodes.html)