GROOVE ("Generating Realtime Operations On Voltage-controlled Equipment") was a digital-analog hybrid system at Bell Telephone Labs., Murray Hill, NJ that ran from the end of the 1960s until the end of the 1970s.

A Quick Description of the GROOVE Hybrid System

by Laurie Spiegel, Oct., 1998

GROOVE - A Quick Description

GROOVE consisted of a general purpose computer, various input and output devices (sensors, controllers, analog audio modules, displays, memory) and several libraries of FORTRAN IV and assembly language code modules, all interconnectable by programs written by individual users for specific pieces or purposes. Each user would write FORTRAN programs consisting of library calls and original code, to interface these component modules, both hardware and software, via whatever logic one wished to try.

In principle GROOVE was the ultimate synthesizer. It allowed the arbitrary interconnection, via user-programmed logic, of analog and digital input, output, hardware, and software modules, including ever-accumulating numbers of library-resident code modules written by users over the years, and increasing numbers of gizmos built mostly by Max.

Unfortunately the real world implementation of this outstanding system design was subject to the hardware constraints of the day (starting late 1960s), most limiting of which was not the mere 32k of RAM or the slow (in retrospect) CPU, but the bottleneck of too few DACs and other converters for translating data between its digital and analog forms for use by various modules.

By the mid-1970s, the system had been put to many highly individualized uses. Max Mathews often programmed the system for his pioneering work on realtime control parameters and devices for performance of pre-composed musical repertoire. Emmanuel Ghent's work with GROOVE ranged from synchronous control of sound and theatrical lighting, and explorations of algorithmic motives variation, to implementation of a computer-controlled analog reverb. Dick Moore wrote a fugue generator, among other algorithms.

My own use the system focused on the development of realtime control variable sets and transfer function logic for realtime computer assisted composition and improvisation. I often worked with the concept of informational entropy as a function of time. With frame buffer output, I synchronously composed music and animated video. I also collaborated with Ken Knowlton on an auditory illusions of perpetual acceleration.

Many other ideas were explored within the structure of this highly adaptable general system.


Copyright ©1998 Laurie Spiegel. All rights reserved.
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