29. An improvement according to claim 28 wherein the width of the second bus is twice as wide as the width of the first bus.
30. An improvement according to claim 29 wherein said second control means sequentially receives one second data packets from the second bus during one successive bus cycles of the second bus, then said second formatting means disassembles the one second data packet and produces two first data packets, the resulting two first data packets being transmitted over the first bus on the next succeeding two bus cycle of the first bus.