The Blit: A Multiplexed Graphics Terminal

The Blit is a programmable bitmap graphics terminal designed specifically to run with the Unix operating system. The software in the terminal provides an asynchronous multi-window environment, and thereby exploits the multiprogramming capabilities of the Unix system which have been largely under-utilized because of the restrictions of conventional terminals. This paper discusses the design motivation of the Blit, gives an overview of the user interface, mentions some of the novel uses of multiprogramming made possible by the Blit, and describes the implementation of the multiplexing facilities on the host and in the terminal. Because most of the functionality is provided by the terminal, the discussion focuses on the structure of the terminal’s software.