PDP-11/44 Maintenance Card

This document is a "Maintenance Card" for the Digital Equipment Corporation (DEC) PDP-11/44 computer system, published in 1981. It serves as a comprehensive technical reference guide for operation, configuration, and troubleshooting.

The document covers the following key areas:

• Console Commands: Provides detailed syntax, address modifiers, control characters, and specific commands (e.g., Boot, Halt, Examine, Deposit, Self-Test) for interacting with the system via the console. It also lists various console error codes and their meanings.
• System Architecture & Operation Flow: Details the physical utilization and placement of various modules (e.g., CIM, CIS, MFM, Cache, UBI, Memory) within the KD11-Z processor backplane. It also includes a flowchart illustrating the power-up and boot sequences based on different switch settings.
• Registers: Lists numerous CPU and I/O device register addresses (in octal) and offers detailed diagrams and explanations for critical registers such as the Processor Status Word (PSW), CPU Error Register, and Program Interrupt Request (PIRQ) Register.
• Front Panel Operation: Explains the functions of the keyswitches (DC Off, Local, Local Disable, Standby), the three-position toggle switch (Boot, Continue, Halt), and the Light-Emitting Diode (LED) indicators (Run, DC On, Battery, Remote) for system status and control.
• Diagnostics: Presents a recommended list of PDP-11/44 MAINDEC diagnostic programs, detailing their purpose and the suggested execution order.

• Module-Specific Information: Provides in-depth configuration details, jumper settings, and register layouts for various modules including:

  • CIM (M7090): Console Interface Module settings for communication modes (20 mA, EIA, TU58), remote diagnosis, and voltage monitoring.
  • CIS (M7091/M7092): Explanations of Complex Instruction Set processing, CPU interaction, and trap handling.
  • Control (M7095): The function of its S1 switch for power-up booting.
  • MFM (M7096): Baud rate selection, terminal jumper configurations, and status/buffer registers for communications.
  • Cache (M7097): Specifications (KK11-B), switch and jumper controls for cache behavior (e.g., forcing misses), and various cache-related register details.
  • UBI (M7098): UNIBUS Interface Module information, including diagnostic and bootstrap ROMs, map registers, address space jumpers, and physical address generation.
  • MS11-M (M8722) Memory: Details on battery backup, error indicators, power voltage checks, starting address and interleave configurations via switches, and parity control status.

• Memory Management: Discusses relocation constants, control and status registers (SR0-SR3), Program Address/Data Registers (PARs/PDRs), TU58-related configurations, line time clock, and diagrams illustrating 16-bit and 18-bit physical address mapping.

• Power Supply (H7140): Offers troubleshooting steps for the DC LED, lists supplied voltages, explains battery backup status indicators, and provides a table of current requirements for various CPU modules.

The document is intended for informational purposes and its content is subject to change.