TCT review the entire table, particularly for BTAM changes. Add CONSLID=console designation for MVS Multiple Console Support (MCS). You must remove any spool parameter associated with CICS/VSE Report Controller Feature (RCF).

SIT review all the entries since there are VSE and MVS only parameters. Plus, there are new and different suffixes for the pregenerated CICS/MVS management modules. For example:

ABDUMP is removed because of CICS reconstructed dump facilities.

AIEXIT provides the user-replaceable autoinstall program name (was the second value for CICS/VSE autoinstall SIT parameter).

AILDELAY is the delete delay period for autoinst (was the fourth value for CICS/VSE autoinstall SIT parameter).

AIQMAX maximum number of term queued for autoinst (was the first value for CICS/VSE autoinstall SIT parameter).

AKPFREQ this parameter now represents the number of write operations to the log stream buffer before an activity keypoint is taken. The default value is now 4000 instead of 200.

AMXT is obsolete, with the new CICS dispatcher algorithms which removed the need to limit the number of active tasks.

AUTINST is replaced by the AIEXIT parameter.

COBOL2 is obsolete, CICS will initialize it immediately if the COBOL2 library is available.

CMXT is replaced by the MAXACTIVE parameter that is provided on the new TRANCLASS resource definition.

DBP is obsolete, and all backout is now coordinated by the recovery manager.

DBUFSZ is obsolete--all CICS system log output is written directly to the system log stream.

DCT the COLD option is removed, and the default is changed from YES to NO.

DLI is obsolete for both local and remote DL/I support.

FERS is obsolete.

ICVR 0 is the default if RUNAWAY(SYSTEM). You may have found it necessary to specify an artificially high ICVR value, to allow processor intensive transactions to run without being abended as runaway tasks. In CICS/ESA you can specify individual runaway timeout values on the transaction resource definition. This means that you can lower your ICVR value to a realistic limit for the average transactions, and have the definition for these reference the global ICVR limit by means of the RUNAWAY(SYSTEM) attribute.

ICVS is obsolete.

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IBM manual VSE to OS/390 Migration Workbook

OS/390 specifications

IBM OS/390, a versatile operating system, was a cornerstone in enterprise environments and played a pivotal role in mainframe computing. Released in the mid-1990s, OS/390 combined the strengths of IBM's MVS (Multiple Virtual Storage) with new features and enhancements, targeting scalability, reliability, and performance in demanding business applications.

One of the key features of OS/390 was its robust support for multiple users and processes. The system allowed thousands of concurrent users to access applications and data, ensuring high availability and minimizing downtime—a critical requirement for many large organizations. This scalability was supported through various enhancements in memory management and processor scheduling, enabling optimal resource allocation across diverse workloads.

OS/390 was known for its superior workload management capabilities. The Workload Manager (WLM) component allowed administrators to define service policies, specifying how system resources would be allocated according to the priority of tasks. This ensured that critical business processes received the necessary resources while less critical tasks were managed more flexibly.

Another significant characteristic of OS/390 was its commitment to security. The operating system provided comprehensive security features, including user authentication, data encryption, and auditing capabilities. This focus on security was vital for organizations handling sensitive data, ensuring compliance with regulations and safeguarding against unauthorized access.

OS/390 also supported advanced technologies that facilitated integration and development. The system included features like the IBM CICS (Customer Information Control System) for transaction processing and IMS (Information Management System) for database management. These technologies allowed organizations to build robust, high-performance applications tailored to specific business needs.

The ease of network integration was another strength of OS/390. With the advent of the Internet and global connectivity, OS/390 systems could easily interface with various network protocols, enabling businesses to operate in a connected world. This inclusion paved the way for many organizations to expand their capabilities and offer new services, driving digital transformation.

In conclusion, IBM OS/390 represented a significant advancement in mainframe technology, combining scalability, security, and robust workload management. Its rich feature set and support for critical enterprise applications solidified its role as a vital component of many organizations' IT infrastructures, ensuring they could meet their operational challenges head-on while supporting future growth. As technology continues to evolve, the legacy of OS/390 remains influential in the realm of computing.