Dial-MS PIP Program Description

This document describes the DIAL-MS Peripheral Interchange Program (PIP) for the PDP-12 computer, created on December 1, 1970. PIP is an I/O device manipulator designed for transferring and converting data between various devices, supporting both sequential and file-oriented I/O.

Its modular architecture is built upon specialized "handlers" and a comprehensive suite of low-level subroutines. Key functionalities include file management (looking up, copying, and moving files), and interaction with sequential devices (like teletypes, high-speed readers, and line printers) and mass storage devices (such as LINC tape and RK08/RF08 disk units). The document details how the program uses flags to select I/O types, describes the purpose of various subroutines, and outlines the procedure for adding new mass storage or sequential devices by integrating their respective read/write routines into the system. The document also includes extensive flowcharts and assembly listings of the program.