Domain Knowledge and Overview of Mainframe (OS/390)

The main objective here is to give an overall idea about Mainframe concepts particularly in Basics of Mainframe so that there is a strong foundation for the Mainframe Domain. Some of the topics covered here are as below,

TSO/ISPF in OS/390
JCL in OS/390
SPUFI in OS/390
To understand the Basic fundamental concepts in Mainframe.
To understand TSO/ISPF in OS/390.
To understand creating, editing, viewing the datasets in OS/390 environment.

What is a Mainframe?
A Mainframe is.....
Basically a very large computer.
Process several million program instructions per second.
Used in Banking, Insurance, Airline and Railway Reservation systems in order to handle large programs with lots of data.

What are the various Operating Systems?
MVS/SP (Multiple Virtual Storage/System Product),
MVS/XA (MVS/Extended Architecture),
MVS/ESA (MVS/Enterprise System Architecture),
S/360 (System 360),
S/370 (System 370),

What is OS/390?
It is an IBM Operating System most commonly installed on its S/390 line of mainframe server.
It was originally the MVS/ESA OS renamed and repackaged with an extensive set of utilities.
Uses TSO/ISPF for creating and editing, viewing the datasets.
Uses JCL for compiling and executing the COBOL load module.
Uses VSAM (Virtual Storage access method) for file handling in COBOL.
Uses DB2 for storing the information in the database.

What is TSO/ISPF?
ISPF (Interactive System Productivity Facility )runs under TSO (Time Sharing Option) environment.
Allows you to perform most functions available in TSO.
Hierarchical menu driven system and is presented as formatted display consisting of protected and unprotected fields.
Perform many functions on datasets such as
Printing, maintenance, scanning and comparing them against other datasets.
Provides friendly user interface to perform often complicated TSO commands.

What is JCL?
JCL stands for Job Control Language.
It acts as the Interface between the COBOL program and the Operating System in Mainframe (mainly for Batch Processing).
Our Batch jobs are executed in Mainframe through JCL.
Mainly used for compiling and link editing COBOL Load modules.

What is SPUFI?
SPUFI stands for SQL processing using File Input.
It is the DB2 (Data Base 2) interactive menu driven tool used by developers to create database objects.