Inventors:
Richard S. Bianchi - Billerica MA
Dennis R. Flynn - Merrimack NH
Marcia T. Fogelgren - Acton MA
Richard A. Lemay - Carlisle MA
Mary E. Tovell - Newton MA
William E. Woods - Natick MA
Assignee:
Bull HN Information Systems Inc. - Billerica MA
International Classification:
G06F 9455
Abstract:
An emulator executes on a second data processing system as a second system user level process including a first system user level program, a first system executive program, and first system user and executive tasks. An emulator level is interposed between the second system user level process and a kernel level and contains pseudo device drivers. Each pseudo device driver corresponds to a first system input/output device. The kernel level includes kernel processes, each kernel process corresponding to a pseudo device driver. The second system hardware platform includes a plurality of second system input/output devices, wherein each second system input output device corresponds to a kernel process. Each combination of a pseudo device driver, a corresponding kernel process and a corresponding second system input/output device executes in a second system process and emulates the operations of a corresponding first system input/output task and the corresponding first system input/output device. The pseudo device drivers are constructed of a plurality of pseudo device queues, a return queue and a queue manager.