The DOS/Batch FORTRAN Compiler and Object Time System

This document serves as a comprehensive technical manual for the DOS/Batch FORTRAN Compiler and Object Time System. It provides in-depth guidance on the FORTRAN language, its implementation within the DOS/Batch operating environment, and the tools required for program development and execution.

The manual begins with an introduction to FORTRAN as a problem-oriented language, detailing its source programs, compilers, linkers, and execution processes. It covers the fundamental building blocks of FORTRAN, including its character set, various data types (integer, real, logical, complex, octal, hexadecimal, Hollerith, Radix-50), and how variables and expressions are formed. Detailed explanations are provided for different statement types: arithmetic, logical, and ASSIGN statements, as well as control statements such as GOTO, IF, DO, CONTINUE, PAUSE, STOP, and END, which govern program flow.

A substantial portion of the document focuses on specification statements (IMPLICIT, TYPE, DIMENSION, COMMON, EQUIVALENCE, EXTERNAL, DATA) that provide crucial information to the compiler regarding program structure and data allocation. It also extensively covers FORTRAN functions and subroutines, differentiating between library, statement, and external subprograms, and elaborating on system subroutines used for I/O control, error handling, and time/date functions. Input/output operations are thoroughly documented, including FORMAT statements, device handling, file structures (formatted, unformatted, direct access), ENCODE/DECODE for data conversion, and I/O error processing.

Additionally, the manual outlines the operational procedures for compiling, linking, and executing FORTRAN programs, encompassing filename specifications, memory requirements, and the architecture of the FORTRAN Object Time System (OTS) runtime environment. It concludes with detailed descriptions of FORTRAN's internal word formats for data representation, calling sequence conventions for subprograms on PDP-11 systems, a FORTRAN trace package for debugging, and a complete listing of the FORTRAN device table.