CICS Versions and History

CICS has been running the world's online business since 1968. Knowing its history helps you understand why it looks the way it does - and it is a favorite interview topic.

How CICS started

• CICS was developed by IBM in the late 1960s, when companies first needed online enquiry and update systems.
• The first release of CICS came out in 1968, making it one of the oldest software products still in daily use.
• It was built for a simple need: let many terminal users ask questions and update records on the mainframe immediately.
• That same core idea - fast, concurrent, reliable online transactions - still drives CICS today.

Major versions over the years

• 1968 - CICS - the first release; basic online transaction processing.
• 1970s-80s - CICS/OS/VS and CICS/DOS/VS - grew with the System/370 mainframes; command-level programming arrived.
• CICS/MVS and CICS/ESA - versions for MVS and ESA operating systems (CICS/ESA 4.1 is a well-known release).
• CICS Transaction Server for OS/390 - releases 1.3, 2.x and 3.x brought the CICS TS name, RDO maturity and e-business connectors.
• CICS Transaction Server for z/OS - versions 4.x and 5.x added web services, Atom feeds and modern tooling.
• CICS TS 6.x - the current generation, with cloud-style deployment, Java and Node.js support, and API-first development.
• Note:- Most production shops today run CICS TS 5.x or 6.x, but the EXEC CICS commands you learn work across all these versions.

What is new in modern CICS

• Web services and APIs - CICS programs can be exposed as JSON/REST and SOAP services.
• Java and Node.js - besides COBOL, PL/I and Assembler, modern CICS runs Java and JavaScript workloads.
• CICS Explorer - an Eclipse-based tool for developing, deploying and managing CICS applications.
• Cloud-style deployment - applications can be packaged as bundles and deployed with policies like modern platforms.
• Despite all this, the classic 3270 green-screen transaction still runs the core of banking and insurance.

Why history matters to you

• Interviewers love asking when CICS was born (1968) and what CICS stands for.
• Old concepts (PCT, PPT, FCT) still appear in books and interviews even where shops use CEDA.
• Code written decades ago still runs - that is why CICS skills stay valuable for so long.
• When you join a shop, the first thing to learn is which CICS TS version it runs, because tooling differs slightly by version.