Re: ECA VRT DVD 2012.rar
Elodie Akiyama
During the 1980s, Digital Equipment Corporation (DEC) planned to replace its flagship platform and operating system, the VAX minicomputer and the Virtual Memory System (VMS), with new products based on a different architecture and design. The new products were the PRISM architecture, which was a 64-bit reduced instruction set computing (RISC) architecture, and the MICA operating system, which was a distributed and object-oriented operating system.[52] However, these projects faced technical and managerial difficulties and were cancelled in 1988, leaving DEC without a clear strategy for the future.[53] To address this situation, a team was set up to design new VAX/VMS systems that could compete with the RISC-based Unix systems that were gaining popularity in the market.[53] The team tried to design a faster VAX-compatible processor, but failed to achieve the desired performance and compatibility goals.[54] Instead, the team showed that it was possible to port VMS and its applications to a RISC architecture based on PRISM, without losing any functionality or performance.[54] This idea led to the creation of the Alpha architecture, which was a 64-bit RISC architecture that supported multiple operating systems, including VMS.[55] The project to port VMS to Alpha started in 1989, and successfully booted VMS on a prototype Alpha system with an EV3 processor in early 1991.[54][56]
The porting of VMS to Alpha was a complex and challenging task, as VMS was a highly optimized and integrated operating system that relied on many features and assumptions of the VAX architecture.[57] The porting team had to rewrite or modify many parts of the VMS kernel, libraries, utilities, and compilers to make them work on Alpha.[58] The team also had to ensure that the ported VMS maintained binary compatibility with existing VAX applications, which required implementing a VAX instruction emulator and a VAX calling standard on Alpha.[59] The team also had to deal with the differences in endianness, word size, alignment, and floating-point formats between VAX and Alpha.[60]
The porting of VMS to Alpha was completed in 1992, and the first version of VMS for Alpha, VMS Version 1.0 for Alpha AXP Systems, was released in January 1993.[61] The first Alpha systems that ran VMS were the DEC 3000 AXP series, which were based on the EV4 processor.[62] The ported VMS achieved high performance and compatibility on Alpha, and was able to run most of the existing VAX applications without recompilation or modification.[63] The ported VMS also supported new features and enhancements that were enabled by the Alpha architecture, such as larger address space, faster system calls, dynamic linking, shared libraries, and multiprocessing.[64]
The porting of VMS to Alpha was a major milestone in the history of DEC and VMS. It demonstrated the technical excellence and innovation of the DEC engineers and the adaptability and robustness of the VMS operating system. It also extended the lifespan and marketability of VMS in the face of increasing competition from Unix and Windows. The ported VMS became the basis for further development and evolution of the operating system, which is still in use today under the name OpenVMS.[65]