Doc wrote Just out of curiosity, how does one generally learn these business systems? For MVS we have Hercules, for VMS there's the hobbyist program (and either cheap VAXen/Alphas or emulators), but for MPE/iX and i5/OS-OS/400 there's nothing. Is it similar to accordion repair where 2 schools turn out our entire national supply? Or do businesses keep a couple of old machines in the back for people to learn on?