Alpha PCI 64-275

This document describes the Alpha PCI 64-275 motherboard, which is a development platform for systems using the Alpha 21064A microprocessor at speeds from 200 MHz to 275 MHz. The guide covers board features, configuration jumpers (software and hardware), functional descriptions of the DECchip 21072 chipset (21071-CA, 21071-DA, and 21071-BA), system address mapping, and board requirements. It also includes detailed appendices for register descriptions, SROM/flash ROM initialization, PCI address maps, and ordering information for technical support documentation.