Pilot

Abstract

The Pilot operating system is designed for the personal computing environment. It provides a basic set of services within which higher-level programs can more easily serve the user and/or communicate with other programs on other machines. Pilot omits certain functions sometimes associated with “complete” operating systems, such as character-string naming or user-command interpretation; higher-level software provides such facilities as needed. On the other hand, Pilot provides a higher level of service than that normally associated with the “kernel” or “nucleus” of an operating system. Pilot is closely coupled to the Mesa programming language and runs on a rather powerful personal computer, which would have been thought sufficient to support a substantial timesharing system of a few years ago. The primary user interface is a high resolution bit-map display, with a keyboard and a pointing device. Secondary storage generally takes the form of a sizable local disk. A local packet network provides a high bandwidth connection to other personal computers, and to server systems offering such remote services as printing and shared file storage.Much of the design of Pilot stems from an initial set of assumptions and goals rather different from those underlying most timesharing systems. Pilot is a single-language, single-user system, with only limited features for protection and resource allocation. Pilot's protection mechanisms are defensive, rather than absolute, since in a single user system, errors are a more serious problem than maliciousness. Similarly, Pilot's resource allocation features are not oriented toward enforcing fair distribution of scarce resources among contending parties.