Abstract: An electronic asynchronous digital controller for use in microprocessors, computers and other digital systems. The controller stores a present state code which is classified into one of at least two state code classes, such as in either even or odd parity. A programmed instruction subsystem analyzes system inputs and present state code information to provide transition instructions indicating whether a state code transition should occur and the appropriate type of transition. Circuitry is included to assure that transitions only occur from one state code class into a different state code class, preferably by changing a single state code bit. Transition can also only progress if all previous transitions have been completed. The invention further includes methods for asynchronously controlling digital systems.

Abstract: Safety enclosures for use in high speed vehicles such as aircraft and high speed trains. The safety enclosures include an enclosure shell which preferably has two shell walls separated by a crash resistant intermediate material which also provides thermal insulation against fires and acoustic attenuation. The enclosures also advantageously include cooling systems which utilize a refrigerant which is expanded through tubes connected along the inner wall of the enclosure shell. A compressed air supply is provided which supplies breathing air to passengers and is used to expand a crash bag. Air is supplied through both the crash bag at passenger contacting panels and through supply lines which exhaust near the passengers' heads. A motor driven door assembly is controlled to close as the crash bag is being deployed. Exhaust ports having check valves allow positive pressure to be maintained in the cabin of the enclosures to exclude smoke and fire.