XT Hardware Handbook

This document, the XT Hardware Handbook, serves as a technical reference for the XT100 computer system. It is organized into 11 chapters covering system architecture, CPU and memory modules, peripheral modules (keyboard, video, power supply), mass storage subsystems (RD50 Winchester and RX50 floppy disks), optional communications modules, firmware, and diagnostics.

Key contents include: * System Overview: Describes the XT as a turn-key, single-user, desk-top computer system featuring automatic self-testing and modular, expandable architecture using a 6-slot T-rail backplane. * CPU/Memory Module: Details the F-11/MMU processor, memory management, 22-bit address space, and various interfaces (keyboard, printer, communications, and real-time clock). * Subsystems: Provides detailed operational and technical specifications for the RD50 5MB Winchester disk and the RX50 floppy disk drives, including command registers and memory mapping. * Diagnostics & Firmware: Explains the power-on self-test (POST) routines, bootstrap sequences (Primary, Secondary, and Tertiary), and the terminal emulation firmware.

The manual is marked for "Restricted Distribution" and includes comprehensive register maps, pin assignments, and electrical requirements for the various modules.