z/os, oh how I remember interfacing with thee, and hating every minute of it. From what I remember you're spot on, every "file" or "record name"/whatever (main

z/os, oh how I remember interfacing with thee, and hating every minute of it. From what I remember you're spot on, every "file" or "record name"/whatever (mainframes are not unix) was restricted to 8 characters and upper case, also EBCIDIC just because IBM. So many silly legacy things around those mainframes. That said, they literally never had an outage on it the entire time I was there so +1 for reliability and availability. They even replaced the whole mainframe piece by piece.