Yes, we have a new look.

Welcome to the City of San José's new digital front door!

Facility Directory Table List

San Jose Semaphore

Artist: Ben Rubin (2006)

The San José Public Art Program in association with Adobe Systems, commissioned artist Ben Rubin in the creation of artwork for Adobe's Amaden Tower. Not unlike the Semaphore Telegraphs of the 18th century, each wheel of the San José Semaphore can assume four distinct positions and together, the four wheels have a vocabulary of 256 possible combinations that turn into new positions every 7.2 seconds pulsing out a coded message, the content of which is a mystery left as a challenge for the viewers to decipher.

As of October 2012, a new code is being displayed; cracking the encryption technique and deciphering the message is posed as a challenge for the public. To the first person or group to successfully crack the new code, Adobe will award bragging rights and acknowledgment on both the Adobe website and the San José Semaphore website.

Adobe's Almaden Tower is situated directly beneath the flight path for aircraft landing at the Mineta San José International Airport, and the San José Semaphore is sensitive to the passage of aircraft above it. When a plane flies overhead, the wheels react visibly to the disturbance, and its steady rhythm is broken. After the plane has passed, the disks resume their steady, purposeful transmission.

San José Semaphore functions as a beacon in the San José skyline. It is a large and beautiful machine for communication, a slow-motion magnifier for digital communications. Unlike digital transmissions that pass invisibly through the air and through microscopic circuitry, the San José Semaphore's communication efforts are visible for all to see.

District: 3

Report a Concern: (408) 793-04330 or


Other Link


  • (Public Art) Consulting
  • (Public Art) Downtown
  • (Public Art) Permanent Artworks

Public Art - San Jose Semaphore - 1
Public Art - San Jose Semaphore - 2

Return to full list >>

Free viewers are required for some of the attached documents.
They can be downloaded by clicking on the icons below.

Acrobat Reader Download Acrobat Reader Flash Player Download Flash Player Windows Media Player Download Windows Media Player Microsoft Silverlight Download Microsoft Silverlight Word Viewer Download Word Viewer Excel Viewer Download Excel Viewer PowerPoint Viewer Download PowerPoint Viewer