In the late 1980s, Microsoft's version of Unix, Xenix, was installed on more machines than any other version of Unix. Radio Shack sold Tandy HD machines runnin

In the late 1980s, Microsoft's version of Unix, Xenix, was installed on more machines than any other version of Unix. Radio Shack sold Tandy HD machines running Xenix to business customers. In fact, Radio Shack stores themselves used a POS system running Xenix, up until the mid 1990s at least. Microsoft sold Xenix to SCO in 1987.