Hi Actually the thought of a tube based computing isn't all that far fetched. I read an article about creating tiny tube circuits that use emission form a tiny nano wires end to create free electrons that can then be used for things like gates or flipflops. The voltages and power levels are quite small. Still, I find it hard to see how even a small tube can work faster than a 90 nm transistor. The biggest speed issue we have today is the external wiring and not the gate speeds. Dwight