Abstract: A data processing system has a number of separate functional elements which transmit and receive data items between the various functional elements. The functional elements may be, for example, separate address spaces or regions running under a single operating system, or separate operating systems running on separate, but linked, data processors. The data processing apparatus includes a link acquisition request (LAR) stack at the requesting element and a LAR stack full processor for selecting one of several alternative actions when the stack has reached a predetermined size as indicated by a stack full indicator.

Abstract: A data processing system operates under the control of a control program having one or more versions. System dump data is generated on occurrence of an error condition. A dump analysis routine for analyzing dump data indicative of the error state of the system receives constant-format data from a version of a translation routine, the translation routine having one or more versions each corresponding to a version of the control program, and capable of translating the system dump data into the constant format required by the dump analysis routine.