The Evolution of CICS

The Evolution of CICS: The History of CICS on DOS (1970-1987)

CICS initially became available in 1968-69 on what was then the full operating system platforms; PCP, MFT and MVT. It didn't take long before the Disk Operating System (DOS) customers were asking for a transaction management system for their platform. Don Hilgers was the IBM Systems Engineer (SE) working with the Ohio Edison account and was instrumental in pressing for a version of CICS that could run on the DOS platform and provide function similar to the OS version.

On September 23, 1970, IBM announced two versions of CICS that would run on the DOS platform; CICS/DOS-Entry (CICS/DOSE) and CICS-DOS Standard (CICS/DOSS). These new products became available in September 1971 and November 1971, respectively. An evolution had begun.

CICS/DOSE and CICS/DOSS offered functions similar to the parent OS product, however internally, DOS operating system facilities were used in place of their counterparts on OS. This required quite a bit of development on CICS' part because operating system facilities for storage, program and file management were considerably different between OS and DOS. But, the adjustments were made, and CICS became available to the DOS user.

The initial announcement for CICS on DOS included support for COBOL and Assembler. In June 1971, IBM announced the addition of PL/I support to the CICS/DOS products. In July 1971, when IBM announced support for the 3270, CICS announced that both the CICS OS and DOS products would support the new display terminal.

As new hardware became available, CICS was quick to provide support on OS and DOS, for instance, support for the 3330 DASD device. In late 1972 and early 1973, CICS announced support for database products with facilities beyond the standard access methods of the period. CICS announced support for links to DBOMP (DataBase Organization and Maintenance Processor) and VANDL-1 (Vancouver DL/I). DBOMP was an evolution of the previous BOMP software (Bill of Materials Processor) and was widely used by manufacturing accounts. VANDL-1 was a precursor for DL/I DOS/VS which brought hierarchical databases to the small and intermediate user.

DL/I DOS/VS was announced in 1972 but was reannounced in February 1973. The product was a subset of IMS/DB (DL/I) and became available for use with CICS in February 1974.

When IBM announced CICS support of Virtual Storage (VS) systems in February 1973, this included both the OS and DOS CICS products, now to be known as CICS/VS. CICS/DOSE and CICS/DOSS were combined into one product for the VS environment. The VS products did not become available until 1974, so in the meantime, CICS delivered the 1.2 releases of CICS/DOSS and CICS/DOSE in June 1973.

In early 1974, IBM announced the withdrawal of CICS support for the 2311 (DASD), and delivered support for DL/I DOS/VS and CICS/DOS/VS. IBM also enhanced the CICS/DOS/VS product with support for emergency restart. In multiple announcements, CICS/DOS/VS added support for VTAM/SNA devices such as the 3600, 3650, 3270 SDLC, 3767 and BTAM support for the 3740 and S/7.

CICS/DOS/VS 1.0 shipped in March 1974 and CICS/DOS/VS 1.0.1 shipped in October 1974. Release 1.0.1 included support for the 2260 and emergency restart. In November 1974, CICS/DOS/VS announced new installability features known as the Subset Option and the Starter System, both intended to assist the new user.

CICS/DOS/VS 1.1 shipped in January 1975, with support for the IBM 3600 Finance Communications System, and other BTAM terminals. CICS/DOS/VS 1.1.1 shipped in May 1975, with support for a number of VTAM terminals (3600, 3650, 3790). In April 1975, prior to June availability of CICS/DOS/VS, IBM further enhanced the product with support for Temporary Storage emergency restart, VSAM shared resources, console overrides, auxiliary trace and much more.

CICS/DOS/VS 1.2 shipped in February 1976 with support for more VTAM terminals, as well as VTAM functions such as chain assemly and logical records. CICS/DOS/VS 1.3 was announced in July 1976, for availability in February 1977. The new release contained the very significant introduction of the command level programming interface for CICS, also known as the High Level Programming Interface (HLPI). Initially, this support was for COBOL and PL/I, with Assembler support being added in a later release. The 1.3 release also included support for dynamic transaction backout, preassembled CICS and enhanced VSAM.

CICS/DOS/VS 1.4 was announced in March 1978, for availability in June 1978. Significant enhancements in the 1.4 release were the introduction of Intersystem Communication (ISC), command level Assembler support, the new Execution Diagnostic Facility (EDF) and more. DL/I DOS/VS continued to be enhanced and CICS/DOS/VS users could now share DL/I data residing on either DOS or OS (IMS) systems.

CICS/DOS/VS 1.4.1 shipped in June 1979 and could be used with either DOS/VS or the newer operating systems version, DOS/VSE. CICS/DOS/VS 1.5 was announced in September 1979, with planned availability in May 1980. Release 1.5 introduced support for Multi-Region Operation (MRO) and this complemented CICS' ISC support, both now offering facilities for transaction routing and function shipping.

CICS/DOS/VS 1.5 also delivered support for VTAM parallel sessions, a new command level interpreter, a new CICS master terminal transaction, CICS monitoring and other enhancements.

CICS/DOS/VS 1.6 was announced in December 1982 for availability in June 1983. The new release significantly consolidated installation options, as well as Basic Mapping Support (BMS) options, making the product easier to install and use. The new release also introduced the beginnings of Resource Definition Online (RDO), which was expanded in later releases.

CICS/DOS/VS 1.7 was announced in October 1986 for availability in July 1987. RDO was enhanced now to include terminal definitions, as well as a new concept called autoinstall. A CICS Report Controller was added to the product to enable spooling of output while CICS continued to run. Considerable changes were made to emergency restart, such as concurrent tasks during initialization, and deferred open of files until first reference.

CICS for the small and intermediate user continued as a separately orderable product until September 1990, when IBM announced that CICS would become a component of VSE/ESA. CICS then became known as CICS/VSE Version 2 Release 1 and would continue for several releases before the introduction of CICS Transaction Server for VSE/ESA in September 2000.