Your Gramma, "Gramma Nomad", is a person who doesn't really know where she wants to live, so she moves to a new house every game. Then she sends you a telegram asking you to visit her. The object of the game is to successfully navigate your way through the streets of Garbonzo City to Gramma's house.
Nomad was written by Steve Trapp in HP 2000F BASIC and published as type-in source code in Creative Computing Vol. 3, No. 5, September/October 1977.