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0C4 in application when referencing the TCTUA after upgrading to CICS TS 5.1

Question & Answer


Question

Why is my CICS application program checking with an abend0C4 abendAKEA after migrating to CICS Transaction Server for z/OS (CICS TS) V5.1, when referencing the Terminal Control Table User Area (TCTUA)?

I see the the following CICS messages but the SR0001 dump was suppressed:
DFHSR0001 applid An abend (code 0C4/AKEA) has occurred at offset X'FFFFFFFF' in program program-name
DFHDU0201 applid ABOUT TO TAKE SDUMP. DUMPCODE: ASRA

Answer

There was a change made in CICS TS V5 regarding to the default location of the TCTUA. Prior to CICS TS V5.1, the default storage location of the TCTUA was BELOW, meaning it was allocated as a 24 bit address. Now the default has changed to ANY, making it a 31 bit address when possible. To have CICS allocate the TCTUA below the line in 24-bit storage as it did before the change and avoid the 0C4, you can specify the system initialization parameter (SIT) parameter TCTUALOC=BELOW.

A dump of the program check, showed the TCTUA was a 31 bit address. But, only the 24 bit address was referenced because the application was running in 24 bit mode, causing the program check.

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Product Synonym

CICS/TS CICSTS CICS TS CICS Transaction Server

Document Information

Modified date:
15 May 2015

UID

dwa1191158