Abstract: A distributed data processing system is provided that is particularly well-suited for enabling a plurality of single-tasking computers connected to a network to continuously process input from the network and each computer's respective peripherals. A polling routine, resident on each computer, periodically polls the peripherals (including a network adapter) which are connected to the computer. Layered communications software is also resident on each computer and enables each computer to send and receive data to and from the network. The polling routine and layered software call predetermined application procedures in response to input from the peripherals and the network.

Abstract: A computer system for entering, processing and recording sales of items is provided, which is especially suitable for use in retail sales, particularly quick service restaurants. The system includes a plurality of programmable POS registers for entering and tabulating customer orders, an off-line processor for programming the programmable POS registers, shared memory for recording data entered and tabulated by the programmable POS registers, and a communication structure for networking a plurality of programmable POS registers, the off-line processor and the shared memory. In one embodiment, the system includes an access control system for enabling access to the POS registers, the off-line processor or the shared memory if operation of those are authorized.