Stephen D Howell

US Patent:

42991544, Nov 10, 1981

Filed:

Aug 27, 1979

Appl. No.:

6/069977

Inventors:

Ralph N. Dietrich - Georgetown IN
Stephen L. Howell - Jasper IN
John W. Robinson - Jasper IN

Assignee:

Kimball International, Inc. - Jasper IN

International Classification:

G10H 140

US Classification:

84 103

Abstract:

An electronic rhythm generator which comprises a large read only memory having a plurality of rhythm patterns and rhythm break patterns programmed therein, player operated selector switches for selecting a rhythm pattern and a break pattern, scanning circuitry for sequentially addressing the memory to read out the stored rhythm pattern, and, when the break circuitry is activated, reading out the break pattern in place of or in addition to the rhythm pattern. The rhythm generator is contained on a single monolithic integrated circuit chip with the pattern selection being accomplished by an external multiplexer driven by an internally generated scan word. The break activation circuitry automatically corrects for improper matching of a rhythmically incompatible rhythm pattern and break pattern by either ignoring the break command or substituting a compatible break pattern in place of the selected break pattern. Channel inhibit circuitry at the input and output of the memory permits selective playing of certain ones of the instrument channels during a rhythm break regardless of whether the break is generated internally of the chip or externally by means of a separate break generator.

US Patent:

42364361, Dec 2, 1980

Filed:

Nov 8, 1978

Appl. No.:

5/958731

Inventors:

Ralph N. Dietrich - Georgetown IN
John W. Robinson - Jasper IN
Stephen L. Howell - Jasper IN

Assignee:

Kimball International, Inc. - Jasper IN

International Classification:

G10H 1057
G10H 108
G10H 112

US Classification:

84 126

Abstract:

An electronic music synthesizer capable of simulating a wide variety of musical effects, wherein the settings which create the various effects are hard wired on a plurality of selectable circuit boards so that programming of the instrument can be accomplished by the player with minimum effort. The synthesizer encodes a plurality of keys on the keyboard and selects a tone from the tone generator corresponding to the depressed key. This tone is fed through a chain of dividers to create the needed footages, which are then fed to voicing cards that create the different tone sources for the synthesizer. These tone sources are fed into a state variable active filter which modifies the timbre of the tone sources in order to achieve the desired frequency-related effects. The output of the filter is fed to a gain module wherein the amplitude envelope has a controlled attach and decay as well as several different modes of operation such as steady state and percussive, which are selected by means of multiple bit binary words produced at the preprogrammed circuit board. The operating frequency of the filter is controlled by an envelope generator preset in a percussive mode to have a predetermined envelope.