Abstract: A user-programmable telephone switch which resides within a commercially available personal computer. The switch is controllable by either the personal computer's microprocessor or a separate, external host connected to an interface provided within the switch. The switch includes a CPU/matrix card that contains a time slot interchange and a CPU running under a real time operating system. The CPU/matrix card controls the overall operation of the switch in accordance with messages received from the operative host. In general, those tasks or functions which must be performed in real time are the responsibility of the switch, as opposed to the internal or external host. Within the switch, certain tasks or functions may be delegated by the CPU/matrix card to intelligent line cards which contain their own microprocessors having substantial call processing capability.

Abstract: A user-programmable telephone switch which resides within a commercially available personal computer. The switch is controllable by either the personal computer's microprocessor or a separate, external host connected to an interface provided within the switch. The switch includes a CPU/matrix card that contains a time slot interchange and a CPU running under a real time operating system. The CPU/matrix card controls the overall operation of the switch in accordance with messages received from the operative host. In general, those tasks or functions which must be performed in real time are the responsibility of the switch, as opposed to the internal or external host. Within the switch, certain tasks or functions may be delegated by the CPU/matrix card to intelligent line cards which contain their own microprocessors having substantial call processing capability.