ME10 core memory
The ME10 was a core main memory system for the mid-period PDP-10s, principally the KI10. It connected to the so-called external memory bus of either the 18-bit or 22-bit address form; parity is provided to protect the memory contents. An ME10 contained 16KW; it had an access time pf .55 µseconds and a cycle time of 1.0 µseconds.
It was a multi-port memory, with 4 ports per memory system: each port can be independently disabled. The CPU uses one port (in a multi-processor system, one per CPU); the others are used by channels (such as a DF10) for mass storage such as disks.