P-26, P-28 "inversion logique", computer generated algorithmic plotter drawings, ink on paper, 50cm x 45cm, 1970

© 1970 by Manfred Mohr

About the algorithm:
The elements are horizontal, vertical, 45 degree lines, square waves, zigzags, and have probabilities for line widths and lengths.
For each position in a matrix (left to right, top to bottom), the algorithm randomly chooses a new element from the alphabet to add to the existing elements.
In P-26, when the middle position is reached, an element is subtracted from the composite sign in the order in which it was added. Thus the last position in the grid shows the last element added.
In P-28, elements are continually added until the last grid position.

First published:
Catalog, Manfred Mohr, "Computer Graphics, Une esthétique programée", ARC - Musée d'Art Moderne, Paris, 1971 (catalog and show)

About the work:
A drawing from the program P-26, 1970, is in the collection of the Museum Abteiberg, Sammlung Etzold, Mönchengladbach, Germany
A drawing from the program P-28, 1970, is in the Anne + Michael Spalter Digital Art Collection, Providence, Rhode Island, USA