A User-oriented Family of Minicomputers Hp's Minicomputer Philosophy Behind

HAT DO MINICOMPUTER USERS want? In setting design objectives for HP's new 21MX Series minicomputers, we tried to make the objectives conform as closely as possible to the answers to this question, as we saw them. Minicomputer applications have broadened tre-m e n d ou s ly-nth e lesffewTcarilOnsfrn dsm puters today solving problems that only a few years ago would have required a large expensive computer system or a dedicated system designed to solve one particular problem. In more and more cases a mini-computer turns out to be the best solution to a problem. What Do Users Want? In general, a minicomputer user wants the most cost-effective solution to his problem. He would like to have the solution as quickly as possible, and not be required to design special hardware to do the job' In addition, he wants a solution closely matched to his specific application, and doesn't want to pay for capabilities he doesn't need or want. Minicomputers should be able to match closely to the number of peripheral devices required by the particular application. If the user needs only four he should not have to pay for twelve I/O slots' Howevet, it is desirable that the minicomputer be extendable, allowing a user to expand the number of peripherals at a later date if this need arises. Physical size is also important to some users. They don't want to have half a rack filled up with the CPU' power supply, I/O system, and so on, especially if they can do the same job in just a few inches of rack space. Different systems require different amounts of main memory, and again users don't want to be paying for capability they don't really need. A dedicated system application may require only up to 32K words of main memory. Another information management Pnnted nUSA system application may require 128K words of main memory today, with the capability of expanding as additional needs arise. And it shouldn't be necessary to trade off physical memory space for I/O controller space. Cover: The HP 21MX Series is a family of advanced minicomputers featuring modular design, a choice of semiconductor memorY sysf erns, user-m tcroPro-g ram ma b I e processors, and cu stomized lnstructlon sets, and a power system that has unusual immunity to substandard electrical conditions. The memory sysfems use the new 4K RAMs, a few of which are shown here.