With my grandfather‘s, he took excellent care of all of his items - in excellent condition- worked last time we used it, which was several years ago .The Vintage Texas Instrument 99/4A Computer is a nostalgic piece of home computing history, made by Texas Instruments in the United States. This vintage computer, known as the "Ciudad de Mexico" or "Mexico City" in reference to its model name, is a sought-after collector's item for enthusiasts of vintage computing. With its retro design and historical significance, this Texas Instrument 99/4A computer is a valuable piece of technology that captures the charm and simplicity of early home computing.