'Hacking The Mainframe': What Hollywood Gets Wrong About Its Favorite Tech Cliche

The comedy blog Slackstory published "An Ode to Movie Mainframes" this week, chronicling Hollywood's age-old obsession with "hacking the mainframe." Movies most often use the phrase to mean that "the hacker can now do anything he or she wants with a given computer system." But in the real world, what exactly is a mainframe and what would hacking into it even entail?

A mainframe is just a big computer, as defined by David Stephens, author of What On Earth Is A Mainframe?, but more specifically the IBM zSeries computers. Simple as that. Mainframes date back to the days when computers were the size of cruise ships -- in the 1970s and 80s, almost every computer was a mainframe, Stephens writes.

But nowadays, most companies -- even big corporations -- don't use mainframes. The manipulation of massive amounts of data, once the hallmark of mainframe computers, can now be done by server farms -- which, Stephens writes, easily connect to other systems, cost far less money, and require less training to administer.

Some older corporations still use mainframes, since switching to a server farm is a lot of work and a lot of money, especially if, as Stephens writes, you've been optimizing your business around a mainframe computer for the last 20 years. So if a hacker is going after an old business, hacking into its mainframe would indeed be a coup, especially since the hacker would likely have to know some very old programming languages.

Clarification: Language has been added to identify more narrowly what Stephens considers a "mainframe" for the purposes of this discussion.