Start Here: The Heirloom PL/I Documentation Map

Table of Contents

1. Two stages: compile-time and run-time
2. Start with the overviews
3. How your code becomes Java (compile-time)
4. Language coverage (what is supported)
5. SQL / DB2
6. CICS
7. IBM MQ messaging
8. Running & operating
9. Suggested reading paths
10. Summary

Audience: anyone working with a PL/I application migrated to Java with Heirloom — developers, operations engineers, and technical decision-makers. This page is a map of all the Heirloom PL/I articles, grouped so you can find the right one fast.

Two stages: compile-time and run-time

Heirloom turns your mainframe PL/I into a standard Java application in two stages, and the articles fall into the same two groups:

• Compile-time (migration) — the compiler translates your PL/I source into Java. These articles explain how your code becomes Java and what controls the translation.
• Run-time (operations) — the runtime and application server run that Java and connect it to your database, queues, files, and screens. These articles explain how the migrated application runs and how you configure it.

If you are new, read the two overviews first, then jump to the topic you need.

Note: Articles tagged (Compiler) are about translating your source; (Runtime) are about running and configuring the result.

1. Start with the overviews

• Understanding Your Migrated PL/I Application — (Runtime) what your application becomes and how it runs.
• How the Heirloom PL/I Compiler Translates Your Code — (Compiler) how PL/I source becomes Java; compiled, not emulated.

2. How your code becomes Java (compile-time)

• Reading Your Generated Java — (Compiler) how each PL/I construct looks once translated.
• Static vs Instance Strategy: Choosing the Right Compile Mode — (Compiler) batch vs online compile mode.
• PL/I Compiler Helpers — (Compiler) diagnosing common compile/parse issues.

3. Language coverage (what is supported)

• Supported PL/I Statements — (Compiler) statements and constructs the compiler translates.
• Supported PL/I Built-in Functions — (Compiler) built-ins the compiler recognizes.
• Supported PL/I Data Types — (Runtime) data types and storage attributes, preserved byte-for-byte.

4. SQL / DB2

• Compiling EXEC SQL Programs (the --sql Option) — (Compiler) how embedded EXEC SQL is translated.
• Supported SQL Features — (Runtime) the embedded-SQL surface that is supported.
• How to Configure DB2 / SQL Connectivity for EXEC SQL Programs — (Runtime) datasources, credentials, isolation.

5. CICS

• Compiling EXEC CICS Programs (the --cics Option) — (Compiler) how embedded EXEC CICS is translated.
• Supported CICS Features — (Runtime) the EXEC CICS command surface that is supported.
• How to Configure and Deploy a Migrated CICS Application — (Runtime) region, registries, deployment.
• How to Build a CICS Application with BMS Screens — (Runtime) BMS maps and the pseudo-conversational loop.
• CICS INVOKE SERVICE Integration Guide — (Runtime) web-service calls from CICS.
• Configuring and Running a Batch Application with CICS Call Support — (Runtime) batch programs that call CICS.

6. IBM MQ messaging

• Supported MQ (Messaging) Features — (Runtime) the MQI operations that are supported.
• How to Use IBM MQ Messaging in a Migrated PL/I Application — (Runtime) connecting to a queue manager.

7. Running & operating

• How the Heirloom PL/I Runtime Manages Memory — (Runtime) structures, pointers, and storage on the JVM.
• How Transactions Are Managed: ETP (etrans) + the Heirloom PL/I Runtime — (Runtime) units of work, commit/rollback, syncpoint.
• JVM Options & Runtime Configuration for the Heirloom PL/I Runtime — (Runtime) tuning, diagnostics, trace.

Suggested reading paths

• New to Heirloom PL/I: §1 overviews → the topic you care about (§4 SQL, §5 CICS, or §6 MQ) → §7 running & operating.
• Developer reading migrated code: How the Compiler Translates Your Code → Reading Your Generated Java → Static vs Instance Strategy → the language references in §3.
• Operations / deployment: Understanding Your Migrated PL/I Application → the relevant configuration article (§4 DB2, §5 CICS deploy, §6 MQ) → §7 (transactions, memory, JVM options).

Summary

• Heirloom PL/I has two stages: compile-time (the compiler turns PL/I into Java) and run-time (the runtime runs and connects it). Articles are tagged (Compiler) or (Runtime) accordingly.
• Start with the two overviews, then go to your topic — language coverage, SQL/DB2, CICS, MQ, or running & operating.