The Architecture of the IRCAM Musical Workstation

The IRCAM Musical Workstation (IMW) is designed to facilitate experimentation with real-time signal processing and event processing. The main focus is on interactive musical composition and performance algorithms. The hardware architecture of the IMW is based around a general-purpose multiprocessor providing sufficient number-crunching power for real-time musical signal processing and event processing. A real-time operating system has been written for this multiprocessor as well as a toolbox that provides support for distributed real-time signal processing and event processing applications. The toolbox also defines an object system to support interactive CAD-like applications. Support for musical applications is in the form of MIDI, digital audio I/O, and music-oriented event scheduling. The multiprocessor consists of a number of processor boards, each with two Intel i860 processors (Intel 1989), that plug into a host computer, the NeXT machine. The host is used for its graphic interface and file system. The i860 processors handle all realtime event processing and signal processing. A number of distributed applications have been written for the system. User interfaces run on the host and communicate with tasks on the multiprocessor. These include Animal (Lindemann and De Cecco 1991), an object-oriented data definition and manipulation environment; MAX (Puckette 1991), a graphical programming language; IMW Signal Editor (Eckel 1990), a tool for manipulating sampled signals in time and frequency domains; and the IMW Universal Recorder (Smith 1990), a multitrack real-time data recorder for spooling event and signal streams to disk. This article provides a general overview of the IMW system with a special focus on the hardware architecture. Musical Signal Processing Architectures