A time- and memory-sharing executive program for quick-response on-line applications

APEX is an experimental operation-oriented on-line data analysis system being developed for the TX-2 Computer at MIT Lincoln Laboratory. This paper describes the executive program which has been designed to satisfy the needs of that system as well as the other activities currently soaking up the computational energies of TX-2. These needs are developed into a set of requirements for a fast-response time-sharing system. The requirements, in turn, lead to a series of design decisions which involve both the hardware and software parts of the system. A memory and program-sharing system, with the hardware to make such a system efficient, takes the form of a complex of apparent computers, one for each console, which share some common hardware (TX-2). The salient characteristics of these computers are described as well as the executive program structure which gives them apparent reality.