1. A method for communicating between a plurality of computers, said method comprising: providing a first computer having a processor, a memory, and at least one communication port; providing a second computer having a processor, a memory, and at least one communication port, said memory of said second computer including a first program of instructions; executing said first program with said second computer; receiving an indication of a second program of instructions at said communication port of said second computer by checking the value of at least one bit at least partially controlled by said first computer against a predetermined value, said second program output from said communication port of said first computer; continuing said executing of said first program with said second computer following said receiving said indication of said second program; pausing said executing of said first program if the value of said at least one bit matches said predetermined value, said pausing responsive to at least one of said instructions of said first program; executing said second program with said second computer; pausing said executing of said second program responsive to one of said instructions of said second program; and resuming execution of said first program with said second computer; and wherein said receiving said indication of said second program does not cause an interrupt in processing functions of said second computer.