The Evolution of CICS

The Evolution of CICS: CICS - State of the Art (1983)

Preface: With each new version and release of the Customer Information Control System (CICS), the product introduced support of new or improved technologies. When reviewing the evolution of CICS, one has to remember the date of the product enhancement, and then consider the nature of the enhancement and why it was important at the time. This article examines the CICS "State of the Art" relevant in 1983.

Good news, bad news? A lot was going on in 1983 and CICS Development had the proverbial "full plate" of things to do. MVS/XA and 31-bit addressability was new, and IMS/VS 1.3 offered the prospect of sharing DL/I data bases, not only between batch and online CICS, but with all of IMS as well (IMS DC and IMS DB). Because of the perceived complexity, IBM decided to announce CICS/VS 1.6.1 and deliver it with so-called "phased build-up" program - meaning an early support program followed by a normal release.

In addition to CICS/VS 1.6.1, other hardware and software products made their debut in 1983. IBM announced the 3290 Information Panel, a large screen, monochrome (orange on black) plasma technology display terminal. An entire computer printout listing could be displayed on the 17 inch screen or the screen was subdivided into as many as 16 separate viewable areas (partitions), most likely two or four. The new terminal was ideally suited for customer network centers or help desk facilities where the person may have a need to deal with multiple systems (and displays) concurrently.

But, the main attraction in 1983 for CICS users was the availability of CICS/VS 1.6.1. CICS delivered its promised enhancements relative to MVS/XA providing 31-bit support. MVS' Resource Management Facility (RMF) was enhanced to provide a new virtual storage report. CICS' Multi-Region Operation (MRO) was enhanced to use the new cross memory (XM) technology. The System Modification Program (SMP) was now enhanced to a higher level called SMP Extended (SMP/E).

CICS/OS/VS 1.6.1 improved its support of DL/I by delivering full data base sharing between batch, CICS and full IMS, based on the availability of IMS/VS 1.3 which was delivered in 1H84. Included in this enhancement was full use of IMS' Database Recovery Control facility (DBRC). Support also included the so-called block level and/or data base level sharing.

CICS MRO was enhanced with a new CICS mirror transaction and internal inter-region transformer logic. This together with CICS' use of MVS/XA's new cross memory (XM) support definitely made the CICS use of inter-region communication a better performer. Clearly, CICS was on the "leading edge".

CICS began to support VSAM with the advent of virtual storage systems, and over some number of releases improved the usability of the new access method. In CICS/VS 1.6.1, Transient Data and Temporary Storage now could benefit from having multiple buffers and strings, for better thruput and performance. CICS/OS/VS 1.6.1 introduced the idea of separate VSAM buffers for CICS File Control and IMS DL/I. CICS/OS/VS 1.6.1 also introduced the EXEC DL/I API to make DL/I access more compatible with the rest of a CICS application. The DL/I call statement remained for those who wished to use it.

The rest of Information Technology (IT) was not standing still in 1983. CICS-related products such as ATMS-III, DMS R4, QMF/VSE and ELIAS made their new announcements, supporting new technologies and co-requisite software. The 1980s have been described as the decade of Field Developed Programs (FDPs) and Installed User Programs (IUPs). New in 1983 were releases of CICSPARS, PAII, SPMOLII, 3270 Simulator, Online Test/Debug and the Formatted Dump offering.

1983 was a busy year for CICS users, with software being enhanced on all fronts. CICS demonstrated its leadership by delivering new technology on a timely basis.