An automatic nail fastening device which is capable of adjusting the spacing and patterning of the nails is presented which is especially useful for nailing decking to a roof. A first cardiac response classification window is established subsequent to delivery of a pacing pulse. The heart rate information may be displayed during and after a dive, and the dive computer may selectively utilize the monitored heart rate information to compensate the decompression algorithm based on workload during the dive. The modification of the access request may occur before the request is sent to the service provider or in response to an authentication request from the service provider. Commercials can be flagged with restrictions against trick play.