AS400 history

I frequently see this question in places like Quora, and it’s both easy and complicated to answer. Mainly because the AS/400 doesn’t exist anymore, but confusingly programmers on it’s successor still call the modern machine “The 400” which causes a lot of confusion.

Who uses the AS/400 anymore?

I doubt anyone is using the old AS400 machines anymore…. they are nearly twenty years old.

AS400 HISTORY – my take on it anyway 😉

It’s successor IBM iSeries was used up until early 2000’s – this was really a re-branding along with some hardware upgrades. This line was sometimes  called AS/400e and eServers – so it’s easy to get confused.

AS400 historyThe old AS/400 range was finally put to the bed with the launch of IBM POWER SYSTEMS – this hardware is hugely changed from the old AS400 machines.

Modern architecture means this range of IBM POWER SYSTEMS really doesn’t even compare to the old creamy AS400 boxes of old. Think of the changes in mobile phones in the last twenty years and this will give you idea of the advances.

These machines are logically partitioned and can run multiple operating systems at once – arguably the most common is “IBM i” – this is a modern version of OS/400 (the operating system and database on the old *400* machines).

Obviously #IBMi is hugely upgraded, with it’s main programming language (RPG) being upgraded so much it’s barely recognizable from the old RPG2 and logic cycle days. But part of the beauty of RPG is that you can still sit down today and write old fashioned 3 line RPG programs using the logic cycle if you wish.

IBM i is totally backward compatible and will still run programs written 20, 30, 40 years ago. While mixing them up with modern RPG ILE routines doing things like webservices…

The problem with this backwards compatibility is that it’s spawned a whole generation of grey-haired programmers who literally haven’t upgraded their programming skills for twenty years. They still write old fashioned code. You can spot them because they normally wear sandals, use flip phones, dont have a Facebook account (It’s too modern) and drive a car from the 80’s 😉

IBM i running on POWER SYSTEMS is the backbone of most big businesses out there today. I’m typing this from Las Vegas where every casino and hotel is powered by IBM POWER SYSTEMS.

Next time you hear someone refer to their current IBM i System as “the AS400” you can gently correct them 😉