Programmed Buffered Display

This document provides comprehensive technical information for the Type 339 Programmed Buffered Display, an on-line system developed by Digital Equipment Corporation to work with the PDP-9 computer. The manual covers system architecture, physical specifications, and display control logic. It details interface considerations, including DMA and I/O bus communication with the PDP-9, and provides deep insights into programming the display system. Key topics include display modes (Point, Increment, Vector, etc.), character generation options (VC38, VA38), and system registers. Additionally, the document contains programming examples, system diagnostic programs, and extensive reference tables for control state, data state, and I/O transfer instructions.