The state of the Art is changing rapidly. In fact I ran into him in New Mexico last month. Seems he had just gotten back from China where he had seen their latest computer. It was really fantastic, but they still have a problem with noise from the beads. I asked Art to clue me in on the latest devices coming out of research and these are the ones he told me about:
You don't get no output no matter what's at the inputs. It is believed that the don't gate was the breakthrough that made the LSI write only memory possible.
When connected across a 1000 volt supply it makes a loud noise (once). The NED was discovered by Igor Pravaganda whom you'll recall worked many years trying to filter AC with electrolytics. He'll always be remembered as the father of the confetti generator.
Must be used with 3 speed forward clutch gate. Shifts at 15, 25, and 35 bits per second. Double clutching with logic 2s is not suggested.
Linear cousin of the DON'T gate. Provides no output for any input at a slew rate of 0 volts per microsecond. Mil Spec. version available at 100 times the cost of OEM version.
Doesn't change state when clocked regardless of input states. Changes state only when cola machine down the hall makes change.
Used to enter Murphy factor and get the programmer off the hook.
Highly experimental material. Very rare at present since only source is from under grizzly bear toenails. Turns green when facing north while on wood substrate.
Great if you want to avoid radar speed traps.