Logical Functions

This document provides a technical overview of the logical functions and operational procedures for the PDP-8 computer. It details the interpretation of flow diagrams used to map out manual, programmed, and automatic operations within the system.

Key sections include:

• System Operations: Explanations of how the computer transitions through time states (SP0–SP3) and machine cycles (fetch, defer, execute) to perform tasks.
• Prefatory Operations: Procedures for powering on the machine, including the use of the Power and Panel Lock switches and the power clearing sequence that initializes system registers.
• Manual Operations: Detailed operational sequences for the console keys, specifically:
  • Load Address (LOAD ADD): Setting the starting address for a program.
  • Start: Initializing program execution from memory.
  • Continue (CONT): Resuming a program that has been halted.
  • Deposit (DEP): Storing information from the switch register into memory.
  • Examine (EXAM): Displaying the contents of specific memory locations.

The document emphasizes the importance of using flow diagrams for maintenance and troubleshooting, noting that each console key triggers a specific series of logical states and signal transfers to control the processor.