VAX PASCAL User Manual (Ver 3.5)

This document is the VAX PASCAL User Manual, published in February 1987 by Digital Equipment Corporation. It is designed for programmers who already have a full working knowledge of VAX PASCAL.

The manual's primary purpose is to guide programmers on:

1. Interacting with the VAX/VMS operating system using VAX PASCAL.
2. Utilizing the full features of VAX PASCAL to take advantage of the VAX/VMS systems programming environment.

Key areas covered in the manual include:

• Overview of VAX PASCAL: Discusses Pascal standards, program structure, and major features including extensions and integration with the VAX/VMS Common Language and Architecture Environments.
• VAX/VMS Operating System Fundamentals: Introduces logging in/out, DCL commands for file handling (displaying, printing, deleting, renaming, searching, setting protection), directory structures, and command procedures.
• VAX PASCAL Program Development: Details creating programs using VAX EDT and VAXTPU, compiling programs with various PASCAL command qualifiers (e.g., for debugging, optimization, listing), linking programs using the LINK command and its qualifiers, and running executable images.
• Debugging: Provides an introduction to the VAX/VMS Debugger, its features, commands (e.g., STEP, GO, EXAMINE, DEPOSIT), and how to control program execution and examine data.
• System Environment & Data Representation: Explains program sections, storage allocation for variables and blocks, allocation sizes, alignment boundaries, and the representation of varying and floating-point data.
• Input/Output with RMS: Describes VAX Record Management Services (RMS) file characteristics (record formats, organizations, access methods), I/O error detection, OPEN/CLOSE procedures, file sharing, record locking, indexed files, and considerations for text files. It also covers interprocess communication via mailboxes and remote communication across networks.
• Error Processing & Condition Handling: Discusses the Run-Time Library's default error processing and how to write custom condition handlers for faults and traps using VAX/VMS condition-handling facilities.
• Calling Conventions: Details the VAX Procedure Calling Standard, parameter-passing semantics and mechanisms, and how to call VAX/VMS system routines from VAX PASCAL.
• Program Optimization and Efficiency: Explains compiler optimizations (e.g., compile-time evaluation, code hoisting, inline expansion) and programming considerations for writing efficient VAX PASCAL code.

The document also includes appendices for diagnostic messages (compiler and run-time), errors returned by specific functions, entry points to VAX PASCAL utilities, and highlights differences between VAX PASCAL Version 1 and subsequent versions. It also briefly mentions optional programming productivity tools like VAXLSE and VAXSCA.