Input/Output

This document details the input/output operations and specific peripheral equipment for the PDP-8 computer system. It covers the general technical requirements for interfacing peripheral equipment with the processor, including signal transmission, device selection, and timing.

Key sections include:

• Teletype Model 33 ASR: Describes how the standard Teletype unit is modified for use with the PDP-8 and explains the Teletype Control unit. This section details how the system handles serial-to-parallel conversion for keyboard inputs and printer/punch outputs, including the use of specific IOT instructions and flags to manage data flow and interrupts.
• Teletype Interface: Provides a detailed table of signals and connections between the processor and the Teletype control, and explains the clocking mechanism used to synchronize serial data transmission.
• Type 189 Analog-to-Digital Converter: Describes the functional operation of the converter, which uses a successive-approximation method to convert analog signals into a digital representation in the accumulator, utilizing the processor's memory buffer register and comparator circuits.