Introduction

IBM's Systems Application Architecture® (SAA) has simplified the task of writing communications programs by providing the Communications element of the Common Programming Interface (CPI). CPI Communications, also called SAA communications interface, provides a programming interface for advanced program-to-program communications (APPC).

SAA CPI Communications defines a set of routines and parameters that are consistent across SAA environments. An application written using CPI Communications on z/VM can be transported to other SAA environments, provided the application does not use product-specific routines.

This book will help you get started writing simple communications programs using z/VM's implementation of CPI Communications. It can be viewed as an introduction and companion to CPI Communications Reference, which fully describes SAA CPI Communications and product-specific extensions.