San José Semaphore – Overview

Like the Semaphore Telegraphs of the 18th century, the San José Semaphore is a machine for communication.

Each wheel of the San José Semaphore can assume four distinct positions: vertical, horizontal, and left- and right-leaning diagonal; together, the four wheels have a vocabulary of 256 possible combinations. The San José Semaphore transmits its message at a steady rate; its four wheels turn to new positions every 7.2 seconds.

The new code is ready to be cracked

As of October 2012, a brand-new code is now being displayed at the top of Adobe's Almaden Tower. You can also view the transmission on this website.

The content of the San José Semaphore's message is a mystery; 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.

Viewable in downtown San José

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 San José Semaphore reacts 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.