What on Earth is a Mainframe?: A review

Last Updated on November 27, 2018 by Dave Farquhar

I’ve been reading David Stephens’ self-published What on Earth is a Mainframe, (also available on Amazon) which is as close to z/OS For Dummies as we’ll ever see.

I deal with mainframes at work from time to time. I interacted with an old IBM mainframe of some sort when I was in college, using it to get on the Internet, do e-mail for classes, and write programs in Pascal. That mainframe has been gone almost 20 years now, but it’s more mainframe experience than most of the people in my department have.

That’s the thing. Mainframes have been on their way out for 20 years–which was why Mizzou retired Mizzou1–but they aren’t any closer to the door now than they were when I was in college. I wouldn’t call it a growth industry, but there are some tasks that haven’t managed to migrate down to smaller iron yet, and if they haven’t by now, maybe they never will. But the universities aren’t producing new mainframe administrators–ahem, IBM calls them system programmers–so while it’s not a growth area from a numbers perspective, it’s a marketable skill that isn’t going away.

That’s where this book helps.

Part of the problem is the language barrier. You see this a little bit when you cross the world between PCs and Macintoshes–“crash” in the PC world means a program hanging or the operating system bluescreening, but on a Mac it only means a catastrophic hardware failure–but the language barrier between small computers and mainframes is much greater. Most mainframe people are forgiving and can translate “sysadmin” to “system programmer” and “file” to “data set” and “disk” to “DASD” and “VM” to “LPAR,” but if you ask for something in their own language, it helps a lot when you’re trying to get things done. They appreciate you going to the effort to understand their world.

Reading this short book (less than 200 pages) doesn’t make you an expert, but it introduces you to the language and the concepts, some of which are familiar to veterans of smaller computers and some of which are anything but. You can certainly read it over a weekend and come to work smarter on Monday.

What else is there to say? Unlike many self-published books, this one is well written and edited. There’s probably a punctuation mistake or two in there somewhere, but you won’t be stumbling over them on every page, unlike many self-published technical books I’ve seen.

Reading this book is good for your career, without being a huge investment of time or money. Mainframes aren’t going away. Mainframes were supposed to be on their way out in 1987, but they’re still hanging around. Knowing something about them, especially if you know something about network security, will open a lot of doors for you. Every large company needs someone like that, and they’ll realize it as soon as they realize they’re talking to one.

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