CICS/VSE on z/VSE 4.3: VSAM EXCPAD
Ingolf24 120000DRN3 Comments (3) Visits (2872)
On February 23 I posted a blog entry, where I described CICS/VSE support on z/VSE 4.3.
Just to recall: The last release, where you had a full CICS/VSE environment, was z/VSE 4.2. CICS/VSE can not run on z/VSE 5.1. CICS/VSE support ended October 31, 2012. That is the only supported CICS on z/VSE is CICS Transaction Server for VSE/ESA.
z/VSE 4.3 dropped the compatibility environment and replaced DL/I DOS/VS 1.10 and DL/I VSE 1.11 by a new DL/I release - DL/I VSE 1.12. DL/I VSE 1.12 only supports CICS TS. However, CICS/VSE can still run on z/VSE 4.3, if you are not dependent on DL/I. CICS/VSE can not run on z/VSE 5.1.
Initially the VSAM EXCPAD exit supported AMODE 31 (31 bit addressing) only. That is EXCPAD could not be used by 24 bit applications in CICS/VSE.
The issue is resolved in between through APAR:
More information is here.
Background: An EXCPAD exit routine receives control from VSE/VSAM when an I/O operation is started or when a task can be forced to wait for an SHR(4) lock. By supplying an EXCPAD exit routine, you can overlap VSE/VSAM I/O or SHR(4) locking operations with the execution of your processing program. The exit routine must return to VSE/VSAM, so that VSE/VSAM can return to your processing program at the instruction following the I/O request macro.