Wiki / Sources

pbrick.info

A blog that became an archive. VLL, RCX firmware, the Scout SDK and Spybotics missions, kept in one place while the rest of the web dropped them.

Most useful sections

RCXVLL (p=58): the rcxvll.nqh library + article "Controlling a MicroScout from an RCX using VLL" → rcxvll.nqh (pbrick). Source download: wp-content/uploads/2013/10/rcxvll.nqh_1.zip.
RCX Firmware (p=74): firmware versions (firm0309/0328/0332.lgo, Dick Swan's fast0612), upload via NQC → RCX / NQC · BrickCC.
Scout SDK (p=184): blue Scout programming (ScoutTool/ScoutDOS, LEGO Assembler) over 9-pin serial.
Spybotics (p=127) + FAQs/Extra Missions — Spybotics IR comms, NQC, missions.
Points to upstream protocol authors: elecbrick (Doug Eaton), Barnaby Walters (author of rcxvll.nqh, which pbrick.info hosts).

The article notes an RCX emits VLL by flashing a 9V light brick on an OUT port.