LSI-11 WCS User's Guide

This "LSI-11 WCS User's Guide" (1978) provides comprehensive information for users to write, assemble, debug, and execute microprograms on the Digital Equipment Corporation LSI-11 computer using the KUV11-AA Writable Control Store (WCS) option.

The document covers:

• Introduction to Microprogramming: Defines key terminology, outlines the benefits of user microprogramming (e.g., faster arithmetic, I/O, data manipulation), and discusses its system implications.
• LSI-11 Machine and Micromachine Structure: Details the architecture and operation of both the main LSI-11 system (processor, memory, I/O) and its internal micromachine (Data and Control chips, MICROMs), explaining control flow and interrupt handling.
• LSI-11 Microinstruction Set: Provides a functional organization and detailed explanation of the various microinstructions available for data manipulation, data access, and microprogram control.
• Writable Control Store (WCS) Hardware: Describes the WCS module's memory organization, microaddressing modes, and its interfaces to the LSI-11 system bus and microinstruction bus, including registers for control, status, and microaddress tracing.

• Microprogramming Support Software: Introduces the essential tools:

  • MICRO: The microassembler for writing microcode.
  • WCSLOD: The loader and dumper for WCS memory.
  • MOOT: The Micro Octal Debugging Tool for debugging microprograms.

• Microprogramming Techniques: Offers guidance on writing microprograms, including instruction decoding, operand passing, and controlling microinstruction flow.

• Installation and Maintenance: Provides procedures for installing and checking out the WCS module, as well as general maintenance guidelines.

In essence, the guide empowers users to extend the LSI-11's instruction set by implementing custom operations in microcode, supported by dedicated hardware and software tools.