dtj v04-04 1992

This special issue of the Digital Technical Journal, published in 1992, is dedicated to Digital's Alpha AXP architecture and systems. It presents a comprehensive overview of Digital Equipment Corporation's strategic initiative to establish Alpha AXP as a universal, high-performance, 64-bit RISC computing platform for the next 25 years. The key goals driving its development were high performance, longevity, and easy migration from existing VAX and MIPS architectures.

The document covers various facets of the Alpha AXP program, including:

1. Architecture Design: Richard L. Sites' foreword and article detail the fundamental architectural decisions behind Alpha AXP, emphasizing its design for multiple instruction issue, shared-memory multiprocessing, and the use of PALcode for operating system flexibility. It highlights the DECchip 21064 microprocessor as the first implementation, touted as the world's fastest single-chip microprocessor (operating up to 200 MHz).
2. Hardware Systems:
   • The design of the DECchip 21064 itself is thoroughly described, covering its CMOS technology, dual-issue capability, pipelining, and external interface.
   • The Alpha Demonstration Unit (ADU) is presented as a high-performance multiprocessor prototype crucial for early software and chip development.
   • The DEC 3000 AXP systems (workstations) and DEC 4000 AXP departmental server computing systems are detailed, showcasing their crossbar and Futurebus+ interconnects, respectively, designed for balanced performance, low memory latency, and high I/O throughput.
   • The DEC 7000 and DEC 10000 AXP family are introduced as powerful mid-range and mainframe platforms, emphasizing their high-performance interconnect for multiple processors and memory arrays, with upgrade paths from VAX processors.
3. Software Migration and Development Tools:
   • Porting OpenVMS from VAX to Alpha AXP discusses the challenges and solutions for migrating Digital's flagship operating system, including handling architectural differences and large codebases.
   • The GEM Optimizing Compiler System is highlighted as a portable, modular compiler designed to produce high-quality code across various languages and target platforms, crucial for maximizing Alpha AXP's performance.
   • Binary Translation explores techniques like VEST (for OpenVMS VAX to OpenVMS AXP) and mx (for ULTRIX MIPS to DEC OSF/1 AXP), enabling existing binary software to run efficiently on Alpha AXP.
   • Porting Digital's Database Management Products (DEC Rdb and DEC DBMS) details the efforts to move complex layered products to Alpha AXP, prioritizing a common source code base and ease of migration.
   • DECnet for OpenVMS AXP: A Case History illustrates the process of porting networking software, emphasizing common code strategies and lessons learned.
   • Using Simulation to Develop and Port Software describes how software simulators (Mannequin, ISP, AUD) facilitated concurrent hardware and software development, enabling early debugging and performance analysis.
4. Program Management: The issue concludes with an article on Enrollment Management, Managing the Alpha AXP Program, providing insights into the innovative management strategies and "cusps" (critical project events) that contributed to the success of this large-scale engineering initiative.

Overall, the document demonstrates Digital's comprehensive approach to launching the Alpha AXP architecture, covering hardware, software, migration strategies, and the managerial efforts required for such a significant undertaking.