X/OS was an Unix from the computer manufacturer Olivetti. It was based on 4.2BSD with some UNIX System V support. It ran on their LSX line of computers, which was based on the Motorola 68000-series CPUs. Proprietary system was never disclosed, neither after Olivetti's 1997+ crash Adding a second hard disk on the same controller created a crash, thus technicians formatted the second disk only with a third disk on a second controller card destinated to be disconnected after the work