 An optional expansion cabinet could be connected to the system, in addition to two uninterruptable power supplies, one for each zone.It used the KA560-AA CPU module, which contained two 83.33 MHz (12 ns cycle time) NVAX+ microprocessors with 512 KB of B-cache (L2 cache).The module's two microprocessors operated a in lock-step fashion, and like previous VAXft systems, there were two such CPU modules in a system, one in each of the two zones, which operated in a lock-step fashion.