Introduction

This introduction gives a brief overview of the Systems Application Architecture (SAA)
solution.

The SAA solution is based on a set of software interfaces, conventions, and protocols that provide a framework for designing and developing applications.

The purpose of SAA REXX is to define a common subset of the language that can be used on several environments. TSO/E REXX is the implementation of SAA REXX on the MVS system. If you plan on running your REXX programs on other environments, however, some restrictions may apply and you should review the publication SAA Common Programming Interface REXX Level 2 Reference.

The SAA solution:

• Defines a Common Programming Interface that you can use to develop consistent, integrated enterprise software
• Defines Common Communications Support that you can use to connect applications, systems, networks, and devices
• Defines a Common User Access architecture that you can use to achieve consistency in screen layout and user interaction techniques
• Offers some applications and application development tools written by IBM

Supported Environments

Several combinations of IBM hardware and software have been selected as SAA environments. These are environments in which IBM manages the availability of support for applicable SAA elements, and the conformance of those elements to SAA specifications. The SAA environments are the following:

• MVS
  • Base system (TSO/E, APPC/MVS, batch)
  • CICS TS
  • IMS
• VM CMS
• Operating System/400 (OS/400)
• Operating System/2 (OS/2)

Common Programming Interface

The Common Programming Interface (CPI) provides languages and services that programmers can use to develop applications that take advantage of SAA consistency. The components of the interface currently fall into two general categories:

• Languages
  • Application Generator
  • C
  • COBOL
  • FORTRAN
  • PL/I
  • REXX (formerly called Procedures Language)
  • RPG
• Services
  • Communications
  • Database
  • Dialog
  • Language Environment
  • Presentation
  • PrintManager
  • Query
  • Repository
  • Resource Recovery

The CPI is not in itself a product or a piece of code. But—as a definition—it does establish and control how IBM products are being implemented, and it establishes a common base across the applicable SAA environments.