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Remember Mainframes?

When ever I hear about or read about cloud computing, the images of massive mainframes and their connected terminals all over the place.  The reason is simple: as a kid growing up in the 80’s, these were pretty much the computers I knew of based on what I saw at banks and airport check-in counters. In fact, these were still around McGill’s campus in Montreal when I started my undergrad studies in the late 90’s (and not so long ago…right?).


In many ways, I find there are many parallels between mainframe and cloud computing.  A computer terminal of yesterday is much like the thin clients of today that depend on a host computer, such as a mainframe, for it’s processing power.  This is known as the client-server model.  In  many ways, this is pretty much how search engines work: you use a terminal to enter a query and somewhere remotely a very complex operation takes place to deliver search results.

So, what has changed? Well, with almost 30 years of advances in the internet and telecommunications, increasing computer power and all at falling prices, the old mainframe and “dumb” terminals I remember from my youth now seem like something from the stone age.  For one thing, the thin clients of today are smarter and aren’t always tethered to a single mainframe (nor with with really long cables).

What are the differences?

Now we have internet and wireless communications across an array of devices including PCs, tablets and mobile phones and also wearables, appliances and even vehicles–the so called internet of things.  It goes without saying that these devices are also much more powerful than even 10 years ago and can perform a range of tasks on their own.  Another significant factor driving the cloud revolution is that the speed, availability and price of appropriate connectivity is where it needs to be.  Heck, I can now get 6 GB of fast mobile data access a month for under $20!  

On the mainframe side, well, there isn’t a single mainframe anymore.  (Have you ever seen one of these? I got a glimpse of one at a bank I worked at before joining SAP and it looked more like a car wash for golf carts than a computer.)  A cloud computing server can be scattered across many individual servers, which offers more flexibility in adding or removing scale as needed quickly and cheaply in a model similar to utility services. 

Security, however, is a bigger concern.  Mainframes tended to operate on closed systems with those really long cables I mentioned. Now, with just about everything going over the internet, there are risks of being compromised by intruders all along the way.  Just think of all the possible interception risks possible between my Facebook status update over wifi through the local ISP, along undersea cables, across countless internet switches in multiple countries and finally into a server I don’t even know where. This is why security is such an important topic and at the top of agenda for cloud computing service providers.

So, in the end, there are similarities but we obviously can do a hell of a lot more from even more places now more than ever before.

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    • Terminals? Luxury. My first programs were written on a "coding sheet" and mailed to somebody who typed (or more likely mistyped) it onto punched cards before running it and mailing the results (or more likely the errors) back to me!

      Those were the days...

      • I actually owned a desk-sized Litton minicomputer that used drum memory and a paper-tape reader as its main storage and input mechanisms. It didn't really do anything other than take up space and look... interesting... in my rented mobile home. But then it didn't cost me anything, either, except to borrow a pickup truck to haul it home.

      • You had data-entry staff for your coding sheets ?

        Luxury !! We had to do our own !!

        At one of the first places I worked at, the comms gear for the developers office had to be rebooted every so often. The firmware patches were on paper tape, and every so often, we'd get an upgrade (usually paired with an upgrade to the firmware on the device at the other end) in the form of a new roll of paper to mount on the little spool at the side. If the 'upgrade' worked, we'd work. Otherwise we'd go to the pub

        This is a UNIVAC Mylar Green Punched Tape from 1972, but most of the examples I saw were paper.

        • I have used one of those card punches once or twice. They had really good keyboards. Possibly the best I've ever used! Modern keyboards are generally awful in comparison.

          • Modern keyboards are generally awful in comparison.


            I have a Model M keyboard (manufacturer date of 22OCT1986) from Clickykeyboards as my home keyboard. I also have a 1990's model hidden away somewhere for spare 🙂

            When I bought them, they came with a PS2 plug, which I connect to my laptop via a PS2->USB converter).

    • I'm brave enough. That's a VT100 in the picture. I used those terminals. My first 'real' job in the early 80s was as a mainframe sysop. And, really long cables notwithstanding, we had 300-baud dialup access (and some limited 1200-baud lines, woohoo!), plus we were connected via a statewide network to a couple other mainframes and a bunch of state universities that all used our system, so there was definite remote access (the local 'hard-wired' terminals in the university computer center had 9600-baud access, and the sysop terminal in the machine room had 19.2K, which, given that it was all text-based, no graphics, was blazingly fast). Hacking was something of a concern, though at the time it was generally college students just flexing their skills or pranking the administrators, not really anything malicious.

      The full-circle nature of progress is something that has struck me too at times, as we went through the phase of small-scale file servers and more powerful clients in the 90s, then in the 00s we saw the popularity increase of thin clients, Citrix, and VDI terminals paired with significantly more powerful central servers. I remember thinking about the irony of it all. But Jason is right, the cloud computing capabilities of today really represent more of a distributed processing paradigm even if they appear to the user like one big centralized service, so while the parallels with the mainframes of yesteryear are definitely there, so are the differences.

    • Or when a bug might really in fact be a bug shorting out some terminals somewhere 😆

      I don't but it's a story handed down to me from an IT guy we had at a company I worked for...never was able to confirm that, actually.

    • Yeah I remember the terminals across campus, which were shortly replaced after I started college with PC workstations / Mac's using a 3270 terminal emulation client software.  I rarely used the physical ones, and used a PC/mac for emulation instead.  Yep I can say I even surfed the web via mainframe 🙂 .  The mainframe stuff was always seemed "fast" compared to the client/server counterparts.

      The weirdest part about that timeframe is on campus there was running everything from a Mainframe(IBM big iron), AIX unix servers, SGI workstations(including the toasters), SGI servers, Sun Workstations, NeXT workstations, Macs, and Windows PC's.  We even had linux and freebsd systems thrown into the mix.

      Take care,


      • Those are all gone now, including most computer labs, but the power outlets remain so students can charge their laptops, tablets, smartphones and eReaders. 

        Actually, I guess those long lines to buy books are gone too, right?