> I suppose it shouldn't have surprised me, given the simplicity of the interface (just normally-open switches). Sure. Even normal use allowed multiple switche

> I suppose it shouldn't have surprised me, given the simplicity of the interface (just normally-open switches). Sure. Even normal use allowed multiple switches to be on to get diagonal motion ("up" and "left" simultaneously, say), if I remember right. Using states that can't normally occur (up and down at the same time) to add extra functionality is a pretty clever hack.