Several years ago, the rules declared that all devices attached to the OI dashboard had to be battery powered. This was clearly overkill, and the sensible statemant would have been "must not require a 110V outlet. They envisioned people bring up laptops needing a plug, which they hadn't planned for.
I had built an PIC + LCD dashboard reader that stole power from a joyport on the OI - a PIC and a CMOS/LCD display, which dragged perhaps 10 mA from the joystick power circuit. Oh, the weeping and wailing and gnashing of teeth, but yes, we could use it, as long as we could demonstrate that it was not controlling a joyport input.
The next year, in the insane time with Yahoo Groups, my request for the same treatment was not refused, just ignored. Guess I should have used it (tacire consentire est.). Since it made no real difference when we were on the field, but really helped when setting up, we returned the favour, ignored First, and used it only in the pit.
