Basic

This document provides a comprehensive guide to OS/78 BASIC, an interactive programming language designed for scientific, business, and educational environments.

The manual covers the following key areas:

• System Architecture: Explains the four major components of the BASIC subsystem: the Editor (BASIC.SV), Compiler (BCOMP.SV), Loader (BLOAD.SV), and the Run-Time System (BRTS.SV and its overlays).
• Editor Commands: Details how to use the BASIC editor to create, retrieve, save, rename, and clear program files using commands like NEW, OLD, SAVE, NAME, and SCRATCH.
• Programming Basics: Describes the structure of BASIC programs, including the use of line numbers, data formats (numeric and string), variables, and arithmetic operations (including order of operations and relational operators).
• Statements: Provides the syntax and usage for various programming statements, including PRINT, READ/DATA, LET, loop control (FOR/NEXT), branch control (GOTO, IF-THEN, GOSUB/RETURN), and termination (END, STOP).
• File Handling: Covers how to define, open, write to, and read from files using FILE#, PRINT#, INPUT#, and RESTORE# statements.
• Functions: Lists and explains built-in functions for arithmetic (e.g., ABS, INT, RND), string manipulation (e.g., ASC, LEN, SEG$), terminal control (PNT), and debugging (TRC).
• Error Handling: Includes a comprehensive list of compiler and run-time error messages to assist in debugging.

The document concludes with summaries of all available editor commands, statements, and functions to serve as a quick reference for users.