Before distributed computing, most sites—or sometimes entire colleges—had only one
big computer that everyone accessed through terminals or modems. Tom’s one big computer
was a VAX 11/750 running Digital’s VMS operating system. Now, before you
young whippersnappers yawn at the antique 1980s technology and skip to the next
section, there is a lesson here that is still valuable today, so keep reading. The script that
executed on boot-up was rarely changed. The SAs had a rule that if you changed the
start-up script at all, you had to reboot the VAX soon after