CITY.

The mechanical picture

AMSTERDAM · CITY THEATRE · 1983

LOCAL / OFFLINE
FOUR COLOURS. THOUSANDS OF MOVING PARTS.

A screen made of turning colour.

32,000 physical rotors. No light-emitting pixels.

3.5 cm elements · horizontal axles
Image held mechanically
DRAG TO ORBIT · SCROLL TO ZOOM · CLICK A ROTOR
Preparing the mechanism…00.0 / 26.0 s
160 / 160 rows

What the film actually shows.

A source-based recreation of the mechanical colour display at Amsterdam’s City Theatre, shown in a 1983 Polygoon newsreel. This is not a factory CAD model or a certified restoration.

OBSERVED / REPORTED IN THE SOURCE

Film close-up of red, blue, white and green rotors in vertical metal guides

00:10–00:22: four coloured surfaces, curved plastic elements, horizontal axle pins and vertical metal guides. Manual downward rotation shows the sequence red → blue → white → green → red.

00:22–00:30: a horizontal rear carriage travels downward on a chain-driven mechanism. The image changes in a band, rather than every element moving at once. 01:46.5–01:53.5 makes the several-row-deep moving band particularly clear: adjacent rows can be in different stages of turning at the same time.

The narration reports more than 30,000 elements, each 3.5 cm, and an overall screen measuring 8 × 10 metres. It describes Japanese origin, hand-prepared colour separations, computer entry and magnetic-disk storage.

RECONSTRUCTED / NOT VERIFIED

200 × 160 = 32,000 elements is a working grid consistent with the reported order of magnitude and overall aspect ratio. The exact original row/column count, pitch and active-area dimensions are not established by the footage.

The model uses approximately 35 mm-wide rotors on a 40 mm pitch, with a proportionally modelled surround. The reported 10 × 8 m overall measurement does not establish the active image area or pixel pitch; the model is not dimensionally surveyed.

The rear indexing fingers, end gears, motor shafts and detents illustrate how a travelling writer can turn independent rotors. Their precise geometry, colour sensing, reset strategy and control circuitry cannot be recovered from the shots. The drive close-up fades the metal supports to reveal the illustrative indexing collar and finger.

The default eight-row overlap and 26-second pass approximate the thickness and travel speed of the band visible around 01:47. This is an estimate from a partial shot, not a measured complete cycle; the original contact-bank count is not established. The adjustable row window, illustrated banks, quarter-turn profile and 0.2% overshoot probability among changing elements remain reconstruction choices. Overshoot is a brief mechanical rebound that returns to the correct face, not an observed historic fault rate.

Software dithering and local file upload replace the historic tracing, hand colouring and digitising workflow. The optional palette wand samples four colours from the input image and repaints the simulated faces; this custom-palette mode is not historically accurate. Original restores the documented red, blue, white and green. The archival preset is a perspective-corrected still of the already-displayed poster, not the original artwork.

Watch the archival film — Nederlands Instituut voor Beeld & Geluid ↗

Source: supplied device_vid.mp4 and device_vid.json (the transcript contains transcription errors; visual evidence was checked separately). Archive stills remain source material, not newly generated art. All simulation assets and the Three.js engine are embedded; no image is uploaded. Three.js r160, MIT licence, © 2010–2024 Three.js authors.