January 29


AS400 history

By NickLitten

January 29, 2017

IBM i, as400, IBM i StepUp, iseries, SYSTEM38, systemi

Who uses the AS/400 anymore?

I frequently see this question in places like Linkedin, Facebook and Quora, it’s both simple and complicated to answer. It’s Simple because the AS/400 just doesn’t exist anymore! I doubt anyone is using the old AS400 machines anymore…. they are over thirty years old. Complicated because (stupidly) many current day programmers frequently call the IBM i System – “The AS400”.  Sounds crazy right?

Ye Olde AS/400

The good old AS400 comes from an era that was pre-internet, pre-mobile phones and pre-social media. 

Yes, we all secretly yearn for those days, a disconnected nirvana of sorts, but owning an AS400 wont take us back in time (and I know because I have one in my living room) so lets get back on topic…. when floppy disks were sexy and a Giga-byte of storage was a distant dream.

AS400 HISTORY – my take on it anyway 😉

The AS400 ruled for years. But like all good things, it eventually needed an upgrade.

It’s successor, the 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 but continued to run the branded OS/400 operating system.

In a half hearted attempt to clear the confusion the IBM System i re-branding also changed the name of OS400 to i5/OS (but many of the menus on the system still called it AS400) – so it’s easy to get confused.

As400 history

The 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 thirty years and this will give you idea of the ground shaking advances.

Modern IBM Power Systems 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).

Thirty Years of System Evolution

  • 1988 AS/400 (Application System/400) running OS400
  • 1994 AS/400 (Advanced Series/400) running OS400
  • 2000 iSeries running OS400
  • 2004 System i running i5/OS
  • 2008 Power Systems running IBM i

Or in pictures it’s (roughly)  like this:

Ibm as400 history
Ibm system 38
The IBM System 38 – before the IBM System 40 (aka AS400)
As400 b60
The IBM AS/400 is born. It’s big, creamy and like something out of Star Trek
As400 c10
As the AS400 evolved it got smaller and faster
As400 history 1
The iSeries was way more powerful and a modern slinky new black shade
As400 history 2
The IBM System i – was just a re-polished iSeries really… with some go faster stripes
As400 history 3
bringing us to the current generation of IBM POWER systems running the beautifully slick IBM i operating system

Obviously, the #IBMi operating system is hugely upgraded from the old OS400 – but it’s beautifully 100% backward compatible.

IBM i’s main programming language (RPG) being upgraded so much it’s barely recognizable from the old RPG logic cycle days. But 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.

Better than that, RPG is alive and evolving with regular updates from IBM and the focus on modern free format style, vast list of API’s, Cloud based web services and SQL server technology is engaging.

To be honest – IBM’s poorly handled re-branding, confusing dilution of the AS400 brand and lack of marketing is the main culprit (imho of course). Thirty years ago, the new versions of the AS400 launched with a different name (AS400/E, iSeries and then System i) but even the terminal mode menu’s still made reference to “AS400”. Vendors never updated their names to the new iSeries Brand name. IBM never released any form of mainstream social media advertising for the new brand names. Now, it’s the IBM i operating system running on Power System Hardware, but still commonly referred to as the good old four hundred. Silly programmers who call this modern machine the AS400 are angry that management think they are using an old machine from pre-Internet days. This leads to management teams eagerly looking to *upgrade* from AS400 to something modern. Nonsense. Who’s to blame? We (IBM i Software Developers) are 🙁

Me. Rambling. Early morning. only powered by a single coffee.

So why do some programmers still call this modern machine an old fashioned incorrect name?

Unfortunately, the system’s terrific backwards compatibility has spawned a whole generation of feckless grey-haired programmers who literally haven’t upgraded their programming skills for twenty years: They still write old-fashioned code, don’t care to upgrade their programming knowledge and seem to enjoy the complexity and confusion inherent in maintaining source-code from decades back.

You can spot them because they’re invariably grumpy, exude a cleverer than though attitude, wear socks and sandals, use big button flip phones, never comment their code, don’t use social media (It’s too modern) and drive a car from the 80’s 😉

The AS400 is Dead – Long live IBM i

IBM i running on POWER SYSTEMS is the backbone of most big businesses out there today.

As400 history from as/400 to iseries to ibm i on power systems

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 400” you can gently correct them 😉

  • After having to explain the names and architecture changes over the years to many people I finally created this table and now just send it to them.

    A couple of minor corrections to the article.

    While the AS/400 was re-branded to the AS/400 (same name, different meanings) the other name changes brought significant changes with them.

    Many iSeries are still in use.

    We’re running an ongoing survey to give everyone a clearer picture of what the landscape looks like out there in the real world. To eliminate as much bias as possible it’s not being conducted by IBM or any specific vendor. It was also recently sent out to over 23,000 people and the results are starting to trickle in.

    If you want to see what the results look like so far, here’s a link – https://goo.gl/LRo8ki (results are updated daily).

    If you’d like to take the survey, here’s a link to it – https://goo.gl/YFzXBV (all of the questions are optional and you should be able to finish it in less than 3 minutes).

    We’re also building a list of people who are willing to give their opinion on one or more products (pro and con). Here’s a link to it – https://goo.gl/n6Ujfn

    If you lose track of this comment you can find all of the links on the home page at all400s.com


  • “You can spot them because they’re invariably grumpy, exude a cleverer than though attitude, wear socks and sandals, use big button flip phones, never comment their code, don’t use social media (It’s too modern) and drive a car from the 80’s ?”
    Correct, to a great extent, because I am one of them.

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