Intermediate memory array with a parallel port and a buffered serial port

A dual ported buffer memory for a hierarchical memory, cmprising an addressable memory array for multi-bit words and a multi-bit register. Data is transferred a word at a time between the memory array and a multi-bit bus to a higher level in the memory system and between the memory array and the register. Data is transferred a bit at a time between the register and a single serial line. Concurrent operations are possible for transfers between the memory array and the parallel bus and between the register and the serial line.