DEC-10-MKB0-D 1020 1030 Monitor Programmers Reference Manual 196801

This document is a Programmer's Reference Manual for the Digital Equipment Corporation (DEC) PDP-10/20 and PDP-10/30 Monitor Systems, published in January 1968 (with an original printing date of June 1967).

The Monitor is a single-user operating system designed to:

• Increase Throughput: By enabling faster job-to-job transitions (including a Batch Processor) and efficiently overlapping I/O with computation using a priority interrupt system.
• Simplify Programming: By providing device-independent I/O commands and handling the physical details of standard devices, allowing programmers to focus on logical file structures and easily reassign devices at runtime.
• Ensure Upward Compatibility: With later Time-Sharing Systems (10/40, 10/50) and the Batch Processor.

Key aspects of the Monitor and its use include:

1. Operation and Commands: Users interact with the Monitor via a console Teletype, typing commands such as RUN, GET, SAVE, ASSIGN, DEASSIGN, CONT, REENTER, DDT (Dynamic Debugging Technique), INIT, KJOB (Kill Job), and DATE.
2. Modular Design: The Monitor is composed of a Console Monitor (CONMON) for command interpretation and an I/O package. It's customizable, allowing users to build a tailored Monitor with specific I/O service routines, or even integrate their own for real-time or nonstandard devices.
3. Core Layout: It outlines the memory organization, showing the I/O package and Console Monitor residing in upper core, with a job-data area and user program in lower core.
4. User Programming Interface: Programmers use "programmed operators" (UUOs) to call Monitor services for I/O requests and control functions. These include operations for file management (e.g., OPEN, CLOSE, LOOKUP, ENTER, RENAME), data transmission (INPUT, OUTPUT), status checking, and device relinquishing.
5. Data Modes and Buffering: The Monitor supports various data transmission modes (e.g., ASCII, Image, Binary, Dump) and utilizes a ring buffer system for efficient, overlapped I/O.
6. Device-Dependent Functions: Detailed sections describe the unique characteristics, data modes, buffer sizes, and special services for specific peripherals, including Teletype, Paper Tape Reader/Punch, Line Printer, Card Reader, DECtape, Magnetic Tape, and Disk drives, along with their file and directory formats.

The manual also covers setting up job programs, handling errors, and provides appendices on generating a customized Monitor and a summary of Teletype commands. It serves as a comprehensive guide for programmers to effectively utilize and interact with the PDP-10 Monitor System.