International Business Machines Corporation

Kenneth R Veraska

Harry M Yudenfriend

Casper A Scalzi

Thomas Edward Cook

Joseph C Elliott

Thomas J Dewkett

Glen A Brent

Joseph A Williams

Francis E Johnson

James J Antognini

Provides a software-to-software interface and a software-to-hardware interface between software users and a hardware ADM facility (ADMF) in a data processing system. Such software user presents only virtual addresses to the software-to-software interface in a MSB list. The user list defines virtual address spaces, including a 'hiperspace', in a manner that represents physical backing media as different random-access electronic storages, such main storage (MS) and expanded storage (ES). The real data transfers are within or between the backing storages. The user list is transformed into an ADM operation block (AOB), which is assigned an ADM UCB in a UCB queue which is associated with an ADM subchannel. The software-to-hardware interface generates an ORB, containing the AOB address, as an operand of a SSCB instruction which is executed to queue the associated subchannel onto one of plural co-processor queues in the ADMF. The ADMF uses the AOB to perform the requested page moves, and generates an interruption upon completion of each request which is sent to the hardware-to-software interface to remove the associated ADMF request from the ADM software request queue and free the associated ADM UCB for use by another user request.

Method and means for enabling virtual addressing control by software

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Millerton, NY, United States of America

Kenneth R Veraska