VAX-11 PASCAL User's Guide (Ver 1.2)

This document is the VAX-11 PASCAL User's Guide, Order No. AA-H485B-TE, published by Digital Equipment Corporation in March 1981, for Software Version VAX-11 PASCAL V1.2.

Purpose: It serves as a comprehensive guide for programmers on how to compile, link, execute, and debug VAX-11 PASCAL programs within the VAX/VMS operating system environment. It also provides essential information for VAX-11 PASCAL programmers on various system-level interactions and data management.

Intended Audience: The manual is designed for programmers with a working knowledge of PASCAL. While detailed knowledge of VAX/VMS is helpful, it is not always essential, though certain advanced sections (like condition handling) require a deeper understanding of the operating system.

Key Topics Covered:

1. Program Development Lifecycle: Describes the step-by-step process of creating, compiling (using the PASCAL command, qualifiers, and understanding listing formats), linking (using the LINK command and its options), and executing (using the RUN command) PASCAL programs.
2. Debugging: Provides extensive detail on using the VAX-11 Symbolic Debugger for PASCAL programs, including its symbol table, command syntax, operations (e.g., setting breakpoints, examining and modifying program locations/variables, controlling execution flow), and a comprehensive list of debugger commands.
3. Input/Output (I/O): Explains PASCAL I/O operations in relation to VAX-11 Record Management Services (RMS), covering logical names, file characteristics, record formats, OPEN procedure parameters, and methods for local interprocess and remote network communication.
4. Calling Conventions: Details how to call procedures and functions not written in PASCAL, including VAX/VMS system services and Run-Time Library routines. This includes information on argument lists, various parameter passing mechanisms (by-reference, by-immediate-value, by-descriptor), and function return values.
5. Error Processing and Condition Handlers: Discusses both the Run-Time Library's default error processing and the VAX-11 Condition Handling Facility, providing guidance on how to write and establish custom condition handlers for more sophisticated error management.
6. VAX-11 PASCAL System Environment: Explains the relationship between PASCAL and the VAX/VMS operating system concerning program sections, storage allocation for scalar, pointer, unpacked, and packed structured types, and the internal representation of floating-point data.
7. Diagnostic Messages: Appendices summarize compiler diagnostic messages, run-time error messages, and PASCAL-specific messages from the VAX-11 Symbolic Debugger.