Patch Data Transaction Mechanism
Original Publication Date: 1989-Apr-01
Included in the Prior Art Database: 2005-Jan-27
This article describes a patch data transaction mechanism between a DCA (Device Cluster Adapter) terminal and a subsystem controller. "Patch" is one method for mending or modifying a program temporarily. For enabling the patch capability for DCA terminals, three new commands between the DCA terminal and subsystem controller are defined. Terminals attached to the subsystem controller are classified into two groups. They are DCA terminals and TCA (Terminal Control Area) terminals. (Image Omitted) DCA terminals are designed such that most of the protocol processing work is performed by the subsystem controller. On the other hand, TCA terminals are designed to process the most work for subsystem controllers in order to reduce the controller's workload.