Input/Output Tower

An Input/Output Tower is a location in the Computer World of Tron, that programs use to communicate to their users. They regard these towers as religious places and each tower has a Tower Guardian to protect the holy place. Dumont and I-No are examples of Tower Guardians.

Uses
If a program "feels" that his or her User calling him, he/she will go to the I/O Tower to communicate. The program asks for the Guardian's permission to pass and the Guardian, if he allows it, will say a prayer:

After the prayer, the program walks to the inside of the tower and reaches for his/her Identity Disc. With his/her arms extended, he/she releases the disk and the disk floats to the top of the tower and soon flies off into the sky of the computer world, where communication with the User begins.

The tower is not only for communicating with users but also allows users to imprint a code onto their respective program's Identity Disk. For example, Alan Bradley gives Tron the code needed to destroy MCP.

Quote
"All that is visible must grow beyond itself, and extend into the realm of the invisible."