 All memory frames, all busses, and all software and data were fully dual modular redundant.The dual CCs operated in lockstep and the detection of a mismatch triggered an automatic sequencer to change the combination of CC, busses and memory modules until a configuration was reached that could pass a sanity check.Busses were twisted pairs, one pair for each address, data or control bit, connected at the CC and at each store frame by coupling transformers, and ending in terminating resistors at the last frame.