My unicomp model m died after a few years. I never found time to return it to unicomp for repair and ended up discarding it to clear my long to do list. Reportedly, there were cost saving changes over the years that reduced weight and reliability. The weight reductions are definitely real. I might have just been unlucky with the keyboard failure, although I assume it involved the circuitry for making it work with USB, which the original model m keyboards did not have.