 The NMI bus is a 32-bit synchronous bus with a usable bandwidth of 64 MB/s.The VAX 8800 family central processing unit (CPU) operates at 22.22 MHz (45 ns cycle time) and is implemented with discrete emitter-coupled logic (ECL) devices spread over eight modules.The majority of the ECL devices are macrocell arrays with 1,200 logic gates, while the general-purpose registers and floating-point units are custom logic devices developed by Digital.