DECmate

This document is a detailed reference manual for assembly language programming of the DECmate system. It provides comprehensive information on the DECmate hardware, including the VT278 intelligent video terminal, the 6120 microprocessor, and various optional devices like the DP278 communication option, RX278 diskette subsystem, and RL278 cartridge disk subsystem. The manual is organized into chapters covering system architecture, operating procedures, programming the VT278 instruction set, programming standard I/O devices, and programming instructions for optional devices. It also includes several appendices with reference data such as character sets, keyboard layouts, and detailed system specifications.