The Mainframe

Mainframes have been around for 40 years and continue to provide the processing power for most of the world’s largest organisations. The mainframe has continued to develop in those organisations and has now evolved into a multi-function platform with large batch applications, web applications, and database servers. The majority of the mainframes in the market today are from IBM and many of those machines have IBM systems software:

• z/OS - the IBM proprietary operating system developed in 2000 with a lineage that goes back to the first IBM mainframe
• JCL – a language that tells the operating system what resources are required to run a batch job or start a system task
•CICS – an online transaction processing system that manages the sharing of resources and establishes the priority of execution
• DB2 – the IBM database product developed out of Codd’s data manipulation model in 1970 and later morphed into RDMS and then ORDBMS

The programming at this level is highly complex and involves decisions that can impact the continuity of business across the entire organisation. Systems programmers can work in machine code such as Assembler and have always been regarded in mainframe circles as the technical elite. Little has changed except the scale of the systems they manage.

The application-programming environment on the mainframe systems has generally been COBOL, a language that was first developed in 1959. COBOL programming proliferated so that, today, many organisations like National Australia Bank and Health Insurance Commission still retain core business systems written in that language.

There are a number of other roles in the mainframe environment including database administration, systems administration, and production management, and production managers. You can specialise in any one of these or move into business analysis, project management and, ultimately, the IT executive.

Core business systems are often so large and complex that it is easier to integrate rather than replace. The challenge today is to create web interfaces so that banks, for example, can service customers over the web with transactions conducted at the back-end database through COBOL programs.

Imagine coming into this environment as a graduate with your typical Java or ASP programming skills. You may well understand how to develop the web front end, but you probably wouldn’t appreciate what is happening at the back-end database and all of the intervening application layers. As the integration projects become larger and more comprehensive, someone will have to understand the totality of this commercial environment. Those who do will be the drivers in the future IT industry.