A computer array (10) has a plurality of computers (12). The computers (12) communicate with each other asynchronously, and the computers (12) themselves operate in a generally asynchronous manner internally. When one computer (12) attempts to communicate with another it goes to sleep until the other computer (12) is ready to complete the transaction, thereby saving power and reducing heat production. A slot sequencer (42) in each of the computers produces a timing pulse to cause the computer (12) to execute a next instruction. However, when the present instruction is a read or write type instruction, the slot sequencer does not produce the pulse until an acknowledge signal (86) starts it. The acknowledge signal (86) is produced when it is recognized that the communication has been completed by the other computer (12).