An electrical power supply system including an engine driven permanent magnet generator operable to produce a variable voltage and high frequency output which is converted by a series train ACAC conversion circuit into a fixed voltage and relatively low frequency AC output for supply through a trip switch to an external load. A second lateral edge of the board has a reduced thickness portion which fits into the open side of the I-beam and forms two pockets which accommodate the engagement of two sets of spring fingers which positionally locate and secure adjacent panels together. An interruption of the data stream in the multicast LSP reconstruction procedures can be avoided or reduced, so that the loss of data packets caused by the multicast LSP adjustment is reduced, and the quality of communication of the multicast is improved. The movable anchor lug and the movable base may be lifted and extended to form an upper and a lower open space for the pulley such that the cord may be wound rapidly without obstruction. If affirmative, the route table entry is stored in the forwarding cache, and the packet is sent on its way. Each of the word line sets is connected to a word line enable signal generation unit which stores information indicating whether data has been written to any of the memory cells connected to the word line set.