This paper presents the design philosophy of the Hyperflow visual programming language. It also gives an overview of its semantic model. The primary purpose of the language is to provide a user interface for a pen-based multimedia computer system designed for school children. Yet it is versatile enough to be used as a system programming language. The concept of visually interactive process, vip in short, is introduced as the fundamental element of the semantics. Vips communicate with each other through exchange of signals, either discrete or continuous. Each vip communicates with the user through its own interface box by displaying on the box information about the vip and by receiving information pen-scribed on the box. There are four different communication modes: mailing, posting, channeling, and broadcasting. Mailing and posting are for discrete signals and channeling and broadcasting are for continuous signals. Simple Hyperflow programs are given for the purpose of illustration, in...

We propose a visual language, Hyperflow, for system programming as well as for end user shell programming. Hyperflow is designed for a multimedia pen computer system for children. It is a dataflow-based graphical language similar to Show and Tell. In order to demonstrate the capability of Hyperflow, we solve the programming problem of implementing a help command for children to telephone their instructor or parents using voice communication hardware (modem, microphone, speaker, and a clock). The resulting program includes visual programs to implement device drivers for the modem and clock hardware. 1. Introduction In his keynote speech to the 4th UIST Symposium van Dam urged the unification of the user interface and the application [van Dam 91]. There are two aspects to be considered: First, the user interface and the application must be more tightly coupled, i.e., the user interface needs more "semantic feedback" from the application. Second, there should be a single environment for ...