Short explanatory pages by JAEV on computer and generative art: algorithms, machines, artists and exhibitions. https://jaev.gallery/notes/ JAEV Noteshttps://jaev.gallery/notes/ 2026-10-23T00:00:00Z https://jaev.gallery/notes/john-whitney-digital-harmony/ 2026-10-23T00:00:00Z 2026-10-23T00:00:00Z

In Digital Harmony (1980) John Whitney described the principle of his computer films: every element moves at a whole-number multiple of one speed. How it works.

https://jaev.gallery/notes/harmonograph/ 2026-10-23T00:00:00Z 2026-10-23T00:00:00Z

The harmonograph draws with two pendulums swinging at right angles. Tisley's instrument of the 1870s, how it is tuned, why its lines spiral inwards.

https://jaev.gallery/notes/axidraw/ 2026-10-21T00:00:00Z 2026-10-22T00:00:00Z

The AxiDraw, the pen plotter Evil Mad Scientist made from 2016: travel, resolution, how Inkscape and the command line drive it, and the NextDraw after it.

https://jaev.gallery/notes/bezier-curves/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

How four points define a Bézier curve, how de Casteljau's construction draws it, why Renault and Citroën needed it, and how a plotter draws one.

https://jaev.gallery/notes/boids-craig-reynolds/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Boids is Craig Reynolds's 1986 flocking model: each simulated bird follows three local rules, and a flock appears. The rules, the paper and a live sketch.

https://jaev.gallery/notes/bresenham-line-algorithm/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

How Jack Bresenham's 1962 rule turns a straight line into steps for a pen plotter, with whole numbers only. The rule, the IBM machines and a live sketch.

https://jaev.gallery/notes/john-whitney-catalog/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

John Whitney's Catalog (1961) is a seven-minute film of effects made on an analogue machine built from a wartime anti-aircraft gun director. How it worked.

https://jaev.gallery/notes/circle-packing/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Circle packing fills an area with circles that never overlap: the densest packing, the Apollonian gasket, the random method artists use, a live sketch.

https://jaev.gallery/notes/computer-technique-group/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

The Computer Technique Group was a Tokyo collective that made computer graphics with IBM machines from 1966 to 1969, among them Running Cola is Africa.

https://jaev.gallery/notes/marching-squares-contour-lines/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Marching squares draws contour lines through a grid of values: four corners, sixteen cases, one lookup table. How it works, and the saddle problem.

https://jaev.gallery/notes/game-of-life/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

The Game of Life: John Conway's 1970 grid of cells that live, die and are born by three rules. The rules as first published, the glider, a live sketch.

https://jaev.gallery/notes/manfred-mohr-cubic-limit/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

In Cubic Limit (1973–75) Manfred Mohr used the twelve edges of a cube as an alphabet: subsets of lines, rotation, all combinations. With a live sketch.

https://jaev.gallery/notes/cybernetic-serendipity/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Cybernetic Serendipity, curated by Jasia Reichardt at the ICA in London in 1968, showed computer art, music, poetry and machines. What was in it.

https://jaev.gallery/notes/datasaab-and-swedish-computer-art/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Which Swedish artists used Datasaab computers in the 1960s, and how: Neutron Star, Supersonics and the Lund picture, all through one engineer.

https://jaev.gallery/notes/design-by-numbers/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Design by Numbers, John Maeda's small language from MIT (1999) for teaching designers to draw with code: Paper, Pen, Line, Repeat. With a live sketch.

https://jaev.gallery/notes/desmond-paul-henry-drawing-machines/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

In the 1960s the Manchester philosopher Desmond Paul Henry built drawing machines from wartime bombsight computers. How they worked and where they went.

https://jaev.gallery/notes/diffusion-limited-aggregation/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Diffusion-limited aggregation: particles wander at random and stick where they touch, growing a branching cluster. Witten and Sander's 1981 model, live.

https://jaev.gallery/notes/ems-elektronmusikstudion/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

EMS, the Electronic Music Studio in Stockholm, opened at Sveriges Radio in 1964 and became a computer-controlled studio. Its machines and its history.

https://jaev.gallery/notes/floyd-steinberg-dithering/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

How Floyd–Steinberg dithering turns grey into black and white dots by passing each pixel's rounding error to its neighbours: 7, 3, 5 and 1 sixteenths.

https://jaev.gallery/notes/herbert-w-franke/ 2026-10-21T00:00:00Z 2026-10-22T00:00:00Z

Herbert W. Franke (Vienna 1927 – Egling 2022): physicist, writer and computer art pioneer. Oscillograms from 1954, Quadrate, KAES, Ars Electronica.

https://jaev.gallery/notes/hilbert-curve/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

The Hilbert curve (1891) is one path through every cell of a square grid. How it is built, why near points stay near, and a live sketch.

https://jaev.gallery/notes/hiroshi-kawano/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Hiroshi Kawano, a Japanese philosopher of aesthetics, made computer designs from 1964 with Markov chains and painted the printouts by hand. How it worked.

https://jaev.gallery/notes/hp-7475a/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

The HP 7475A, Hewlett-Packard's six-pen desktop plotter of 1983: how it moves the paper, its speed and unit, its pens, and how to drive it today.

https://jaev.gallery/notes/charles-csuri-hummingbird/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Hummingbird is Charles Csuri's computer-animated film in which a drawing of a bird is broken up, scattered and put back. How it was made, and where it is.

https://jaev.gallery/notes/spirograph-hypotrochoid/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

A Spirograph draws hypotrochoids: a wheel rolling inside a ring. The formula, why the tooth counts decide the number of points, and a live sketch.

https://jaev.gallery/notes/l-systems-lindenmayer/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

L-systems rewrite every letter of a string at once. Aristid Lindenmayer's 1968 idea, how a turtle turns the string into a plant, and a live sketch.

https://jaev.gallery/notes/linear-congruential-generator/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Multiply, add, keep the remainder: how a linear congruential generator makes random-looking numbers, why it repeats, and the one Georg Nees drew with.

https://jaev.gallery/notes/lissajous-figures-harmonograph/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Lissajous figures are the curves of two swings at right angles. Lissajous's tuning forks of 1857, the drawing machines and pendulums, and a live sketch.

https://jaev.gallery/notes/jean-tinguely-meta-matics/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Jean Tinguely's Méta-Matics (1959) were motor-driven machines that made abstract drawings for visitors. How they worked, and how they differ from plotters.

https://jaev.gallery/notes/moire-patterns/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Moiré: the broad bands that appear where two fine sets of lines overlap. How they form, how wide they are, and their place in Swedish computer art.

https://jaev.gallery/notes/plotter-pens/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Which pens plotters have drawn with since the 1960s: the IBM 1627's ballpoint, HP and Roland cartridges, drafting pens and today's fineliners.

https://jaev.gallery/notes/poisson-disc-sampling/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Poisson disc sampling scatters points at random, never closer than a set distance. Why plain randomness clumps, Bridson's 2007 algorithm, a sketch.

https://jaev.gallery/notes/processing/ 2026-10-21T00:00:00Z 2026-10-22T00:00:00Z

Processing, started in 2001 by Ben Fry and Casey Reas at the MIT Media Lab, is a free language for drawing with code. Its origins, and how a sketch runs.

https://jaev.gallery/notes/punched-paper-tape/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

How punched paper tape carried programs and plotter drawings in the 1960s: the eight-track standard, Nake's Graphomat tape, a compiler on tape.

https://jaev.gallery/notes/random-walk/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

A random walk is a path of steps in random directions. Karl Pearson named it in 1905. How far a walker gets, why it comes home, and a live sketch.

https://jaev.gallery/notes/reaction-diffusion/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Two chemicals that react and spread can turn an even mixture into spots and stripes. Turing's 1952 idea, the Gray-Scott model and a live sketch.

https://jaev.gallery/notes/roland-dxy-plotters/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Roland DG's DXY desktop pen plotters of the 1980s: how they work, their step size, speed and pens, the two command languages, and using one today.

https://jaev.gallery/notes/algorists-verostko/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

In 1995 Roman Verostko and Jean-Pierre Hébert named artists who use their own algorithms algorists. The definition, and Verostko's brush plotter.

https://jaev.gallery/notes/rorelse-i-konsten-1961/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Rörelse i konsten (Movement in Art), Moderna Museet 1961: 233 works that moved, a drawing machine by Tinguely, and a tour of 143,000 visitors.

https://jaev.gallery/notes/edward-ihnatowicz-senster/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

The Senster, Edward Ihnatowicz's hydraulic sculpture for Philips's Evoluon (1970–74), turned toward sounds and shied from noise. How it worked.

https://jaev.gallery/notes/knowlton-harmon-studies-in-perception/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Studies in Perception I, the Bell Labs computer nude of 1966: a photograph turned into a mosaic of electronic symbols. The method, and what happened.

https://jaev.gallery/notes/tektronix-4010/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

The Tektronix 4010 graphics terminal of the early 1970s: how its storage tube kept a drawing on screen without memory, its 1024 × 780 points, and PLOT-10.

https://jaev.gallery/notes/tsp-art/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

TSP art draws a picture with one closed line through thousands of dots, found by solving the travelling salesman problem. The method, step by step.

https://jaev.gallery/notes/voronoi-delaunay/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

A Voronoi diagram splits a plane into the areas nearest each point; the Delaunay triangulation joins neighbours. How both work, with a live sketch.

https://jaev.gallery/notes/vpype/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

vpype, Antoine Beyeler's command-line tool for plotter files: its pipelines, what linemerge and linesort do, and how it writes HP-GL for old plotters.

https://jaev.gallery/notes/weighted-voronoi-stippling/ 2026-10-21T00:00:00Z 2026-10-21T00:00:00Z

Adrian Secord's weighted Voronoi stippling turns a grey image into evenly spaced dots, denser where it is dark, by moving each dot to its cell's centre.

https://jaev.gallery/notes/ten-print-maze/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

10 PRINT CHR$(205.5+RND(1)); : GOTO 10 is a one-line Commodore 64 program that draws a random maze. What each part does and where it came from.

https://jaev.gallery/notes/aaron-rules/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Harold Cohen's AARON drew with if-then rules, frequencies and a map of used space. His own 1979 description of the rules, and a small reconstruction.

https://jaev.gallery/notes/air-quality-data-as-art-material/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

What European air-quality stations measure, what nitrogen dioxide and ozone are, the limits, and what to know before using unverified data in a work.

https://jaev.gallery/notes/astrid-sampe-computer-textile/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

How the designer Astrid Sampe and IBM programmer Sten Kallin made printed fabrics from plotter drawings on an IBM 1130, and which of them museums hold.

https://jaev.gallery/notes/beck-and-jung/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Beck & Jung were the Lund artist Holger Bäckström and the engineer Bo Ljungberg. Their image alphabet, line printers and the Chromo Cube.

https://jaev.gallery/notes/benson-plotter/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

The French Benson flatbed plotter Manfred Mohr drew on in Paris from 1970 to 1983: its size, step and paper, and how a drawing reached it.

https://jaev.gallery/notes/bitcoin-difficulty/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

What Bitcoin's difficulty measures, how the target, hash and nonce work, and why the network adjusts it every 2,016 blocks to keep ten minutes per block.

https://jaev.gallery/notes/calcomp-565/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

The CalComp 565, the drum plotter IBM also sold as the 1627: how it moved the pen in steps, the line algorithm written for it, and the artists who used it.

https://jaev.gallery/notes/color-program-mikael-jern/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

COLOR was the software that turned data into dots for the Hertz ink-jet plotter in Lund. How it made tones, solved hidden surfaces and led to UNIRAS.

https://jaev.gallery/notes/michael-noll-computer-composition-with-lines/ 2026-10-20T00:00:00Z 2026-10-24T00:00:00Z

A. Michael Noll's Computer Composition with Lines and his 1966 test: 100 people compared it with a Mondrian. The rules, the results and a live sketch.

https://jaev.gallery/notes/digitalteatern-malmo/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Digitalteatern was Charlotte and Sture Johannesson's Apple II computer art studio in Malmö: what it had, how they worked, why it ended.

https://jaev.gallery/notes/flow-fields/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

A flow field is a grid of angles that curves follow step by step: how the grid is filled, how the curves are kept apart, and where the method comes from.

https://jaev.gallery/notes/generative-computergrafik-stuttgart-1965/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

From 5 to 19 February 1965 Georg Nees showed computer drawings in Stuttgart, one of the first exhibitions of computer art. What was shown and said.

https://jaev.gallery/notes/hertz-ink-jet-colour-plotter/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

How Hellmuth Hertz's ink-jet plotter at Lund University printed computer images in three inks in the 1970s, and what became of it.

https://jaev.gallery/notes/frieder-nake-hommage-a-paul-klee/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Frieder Nake's Hommage à Paul Klee (1965): bands, vertical lines, triangles and circles chosen by chance. The rules, the machines and a live sketch.

https://jaev.gallery/notes/hp-gl/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

HP-GL, Hewlett-Packard's plotter language from 1977: what IN, SP, PU and PD mean, how big a plotter unit is, and how to make HP-GL today.

https://jaev.gallery/notes/ibm-1130-swedish-computer-art/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

A spare IBM 1130 and its drum plotter in Solna made Sweden's first plotter art: Sten Kallin with Astrid Sampe and Sture Johannesson, c. 1970–75.

https://jaev.gallery/notes/vera-molnar-interruptions/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Vera Molnár's Interruptions: a grid of short lines, each turned at random, with areas left empty. What the rule does, with a live sketch by JAEV.

https://jaev.gallery/notes/jan-w-morthenson/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Jan W. Morthenson, Swedish composer, made Neutron Star (1967) on a power company's computer. What the program did and how the piece was made.

https://jaev.gallery/notes/lars-gunnar-bodin/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Lars-Gunnar Bodin, Swedish composer and intermedia artist, made one of the first computer-planned pictures in Sweden in 1968. How he worked.

https://jaev.gallery/notes/line-hatching/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

A pen plotter cannot paint a surface. How a program fills a shape with parallel lines, how spacing and crossing give tone, and in what order the lines go.

https://jaev.gallery/notes/knut-wiggen-musicbox/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

MusicBox was Knut Wiggen's composition program at EMS in Stockholm: music as a network of boxes that pass numbers on. How it worked, and a live sketch.

https://jaev.gallery/notes/commons-images-as-material/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

What CC0 and CC BY allow, what attribution means, where openly licensed photographs are found, and how artists combine many of them into one image.

https://jaev.gallery/notes/perlin-noise/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Perlin noise is a random function Ken Perlin made in 1983 for film textures: how its grid of gradients works, and why it is zero at every grid point.

https://jaev.gallery/notes/plotter-path-optimisation/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Why the order of lines matters to a pen plotter, how a greedy nearest-neighbour sort cuts the pen's travel in the air, and its link to the travelling salesman.

https://jaev.gallery/notes/rgb-colour-cube/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

How a screen mixes red, green and blue light, why that makes a cube of 16,777,216 colours, and how a printed colour cube in ink differs.

https://jaev.gallery/notes/georg-nees-schotter/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Schotter (Gravel) by Georg Nees: 264 squares whose random shift and rotation grow with a single counter. The rule, the random numbers and a live sketch.

https://jaev.gallery/notes/sha-256-as-random-source/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

How a hash function such as SHA-256 turns any text into a fixed 256-bit number that looks random, and why generative artists use it to make choices.

https://jaev.gallery/notes/sol-lewitt-instructions-as-algorithms/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Sol LeWitt's Wall Drawing 86 (1971) is one sentence: ten thousand lines covering the wall evenly. What a program must decide to carry it out.

https://jaev.gallery/notes/sture-johannesson/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Sture Johannesson, Swedish poster artist, turned to IBM's computers after the 1968 Lund poster scandal. How he and Sten Kallin made pictures from one line.

https://jaev.gallery/notes/tendencies-4-zagreb/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Tendencies 4 brought computer art into the New Tendencies movement in Zagreb: a colloquy in August 1968, a journal and an exhibition in 1969.

https://jaev.gallery/notes/truchet-tiles/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

Truchet tiles are squares split along the diagonal into two colours, described by Sébastien Truchet in 1704. How they combine, and what happens at random.

https://jaev.gallery/notes/zuse-graphomat-z64/ 2026-10-20T00:00:00Z 2026-10-20T00:00:00Z

The Zuse Graphomat Z64, the German flatbed plotter of 1961–64 that drew early works by Frieder Nake and Georg Nees: how it worked and where to see one.