the small amount of development on Alpha had changed the nature of the project significantly. Originally conceived as an updated HP 2100, it had become essentially a small Omega, adopting its virtual memory and stack machine design that supported high level languages, but limited to a 16-bit design with a maximum of 64 kWord main memory (128 kB), only a single accumulator, and lacking Omega's powerful input/output systems. When the plan to continue the development of Alpha was presented, George Newman, who replaced Perkins as the General Manager of the computer division, was concerned that the team was once again designing a machine that could not be delivered. Management was eventually convinced of the merits of the design, and the External Reference Specifications were published in July 1970. MPE Prior minicomputers were generally used in a fashion similar to modern microcomputers, used by a single user, and often dedicated to a single particular task like operating machinery. This was true for many contemporary designs like the PDP-8 and Data General Nova. It was the HP 2000's ability to perform timesharing that made it a success in a market of similar machines. The ability to support multiple users running different programs was previously limited to mainframe computers, and a further expansion of this capability was a key design concept for the original Omega. When Alpha emerged as an Omega-like design, it initially followed the same model of multi-user support, which was in turn based on the HP 2000 concept. In this model, the main CPU does not handle user interaction, which is the task of the front-end processor. This allows the main operating system to be greatly simplified, simply loading up user programs as they appear from the front-end, running them in a round-robin fashion with other users' programs, and then delivering the results. In most respects, this was a batch processing system, much of the complexity of multi-user support was isolated in the separate front-end processor. As development re-started on Alpha, this concept was re-examined and the decision was made to expand the operating system to support multiprogramming directly. This resulted in the system becoming three-in-one, with the main portion being dedicated to timesharing but also offering real-time support and batch mode. The resulting system, ultimately known as Multi-Programming Executive (MPE), would be among the most advanced of its era. When the ten groups within the operating system team came