KY11A ConsoleManual Sep1970

This manual, DEC-11-HR7A-D, published in September 1970, describes the KY11-A Programmer's Console for the PDP-11/20 System.

Purpose: The KY11-A console serves as a vital programmer interface, providing manual control and display capabilities for system operations.

Physical Components & Architecture: The KY11-A console is a single circuit board containing switches, lamps, and logic for lamp drivers and switch filters. However, the core control logic for the console functions resides within the KA11 Processor on separate modules (M724 Bus and Console Control module).

Key Console Functions (Chapter 2): The manual details the operational procedures and underlying logic for various console functions when it assumes control of the KA11 Processor and Unibus:

• LOAD ADDR: Allows the operator to manually input a starting address for a program or an address for subsequent EXAM or DEP operations.
• EXAM (Examine): Enables the operator to inspect the contents of a memory location (restricted to even boundaries) and supports sequential examination.
• DEP (Deposit): Facilitates depositing data from the switch register into a specified memory address (restricted to even boundaries), also supporting sequential deposits.
• CONT (Continue): Resumes program execution from an interruption point (e.g., after a HALT) without reinitialization.
• HALT: Manually stops processor operation, transferring control to the console, with its behavior influenced by the S-INST/S-CYCLE switch setting.
• START: Initializes the PDP-11/20 system and commences program execution from an address previously set by the LOAD ADDR function.

Power-Fail Operation: The document extensively covers power-fail operation, which can be activated by the console's OFF/POWER/PANEL LOCK switch or a disruption of AC power. This feature provides hardware support for handling power interruptions gracefully through:

• Power Fail Down: A trap sequence to address 000024 to store volatile information and set a program flag, requiring a HALT instruction to conclude.
• Power Fail Up: A modified trap sequence to 000024 upon AC power restoration, designed to reload stored information and restart the interrupted program. The console's ENABLE/HALT switch influences whether power-fail trap routines are executed or if control directly transfers to the console.

Module Description (Chapter 3): This section briefly outlines the internal logic responsible for the console's display and input:

• Lamp-Driver Logic: Explains how processor output signals control the 42 indicator lamps on the console panel.
• Switch Logic: Describes how inputs from the console switches (for Address, Data, and Control displays) are derived from the Bus Address Register (BAR), Data Paths, and various machine states, including filtering mechanisms to manage contact bounce and panel lock.

The manual includes several engineering drawings (e.g., Console Flow, Console Panel, Console Assembly) to visually represent the detailed implementation and operational flow of these functions.