AIPOS Job Control Processor Internal Description

This document provides an internal description of the AIPOS Job Control Processor (JCP), a software component developed by Digital Equipment Corporation in May 1971. The JCP is built from three main assemblies: JLnn, CMnn, and XSnn/XSBnn.

The JL module manages interactions with the Monitor, encompassing end-of-job cleanup routines, loading of field 1 sections of Job Control, and the binary loader. The CM module contains the command interpreter and display routines, responsible for processing user input, validating commands, and handling delimiters. The XS and XSB modules provide comprehensive index services, including file lookup, allocation of working areas for files, and end-of-job file saving (EJS). A serially reusable DX command, managed by XS, allows users to interactively display and manipulate file indexes by deleting, aliasing, renaming, printing, and navigating entries.

The document details the functionalities of these routines, provides a core map illustrating memory allocation and overlays for various modules in both Field 0 and Field 1, and includes flowcharts to visualize key processes such as command input and delimiter handling. Detailed assembly code listings for the component modules are also included.