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An Intimate Conversation About 5250 Emulation

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Like an old friend who never seems to go home, emulation is always with us, enabling us to connect our new-fangled computer devices to an i that wasn't really designed for that type of connection.


We don't think about emulation much, but without it, where would we be?


Back in the olden days, connecting to the i was easy. You just ran some Twinax under the floor or through the walls and straight up to the back of your computer. The cabling was inconvenient because it limited your ability to rearrange your office unless you were adroit enough to not trip over wires running out in the open.


The 5250 display unit (which, of course, is why they call it 5250 emulation) was a version of the 3270 dumb terminal used by the 370-type machines and was built for the System/3 and then used on the S/38, the AS/400, etc. It was large and clunky but had the durability of a tank. It had some luxury features as well, such as a color screen (yes, black is a color, and there was green too) and a mechanical feedback style of keyboard that made noise when you typed, thus simulating the familiar sound (back then) of a typewriter. As cubicles became all the rage, it was an easy way to tell if someone was working.


The 5250 connected to the host computer via the SNA protocol and was responsive in that any information that was typed was buffered on the machine (for rapid movement from field to field) and then sent en masse to the host when you hit Enter. Another improvement was the introduction of a "busy" indicator that told the operator when the terminal was busy unloading or loading that buffering.

And Then PCs Started Appearing

It all started falling apart when PCs began to make their appearance in the business world.


At first, it was common to have two big, clunky screens on your desk: one for the 5250 and the other for a PC that could be used for email and playing solitaire. Although this arrangement was ideal for helping the users hide what they were really doing, in many cases it left precious little space for someone to lay their head on the desk when the afternoon snoozies rolled around.


This ushered in a time of great change and uncertainty in the network and display world. People began to move away from Twinax and instead started deploying TCP/IP networks. Because midrange systems like the AS/400 used the SNA protocol, there was a need for gateway solutions and physical emulation cards in the PCs in order to allow TCP/IP and SNA to coexist. A number of companies, including Microsoft (MS SNA Gateway), Turbosoft's TTWin, etc. jumped into the mix and offered products in addition to IBM.


The one person most responsible for the development of a software-based emulator, eliminating the physical cards and gateways, was a guy named Joseph Frank. An engineer at IBM who architected SSP, the forerunner to OS/400, he left IBM in 1980 and started his own firm to develop this product. Although IBM told him he was crazy, he persevered and the emulator market was off and running.


Suddenly, an enormous market opened up, and emulator products were as common as kale-based recipes are today. Rumba was one of the more popular and was the first one that I used, but there were many of them to choose from, including IBM's Client Access.


Because Client Access appeared as a separate line on the IBM invoice and was relatively expensive per user, a lot of people started looking around for alternatives. This was right at the beginning of the "every IT budget must be lower than the year before" era, and it was easy to make a case cost-wise for going with a different emulator. But when IBM switched to subscription-based pricing near the turn of the century, that blanket covered Client Access, and to a lot of people it seemed like it suddenly was free. It wasn't. You still had to buy per-user copies, although you could get a deal based on your price point. But it was one factor in knocking the bottom out of the emulator market, and many products disappeared.


Interestingly enough, even though Mr. Frank died a number of years ago, his product is still being enhanced and sold, currently under the name WinTronix IP Client TN5250e (formerly Synapse IP Client, Synapse WINAPPC, and Synapse NetWolf) through Trilobyte Software. Its functionality looks pretty good. (Advanced printing options, file transfer options, even the ability to do sound effects, and if you have 2000 or more users, you can get it for just $7.43 per user.)

And Today?

Today, unless you have an old 5250 terminal sitting in your computer room (do people even have computer rooms anymore? computer closets?), you're probably using a PC, most likely connected via wireless that's running some emulator software to connect to the i. The most common product that does this is, of course, IBM's own IBM i Access for Windows.


The other thing about today is that fewer and fewer users are using an emulator. Is your software running on a browser? I mean directly on the browser as in a PHP or Ruby script. If so, then you're not using an emulator. It's possible that we're working our way to the point where the only people who will require an emulator are the technical staff who use the green-screen IBM i command facilities.

What You Should Look for in an Emulator

To quote an old AS/400 hand, Roger Pence of ASNA, "You don't pick a toilet seat for its features; you pick it for a quick place to sit. Short of that toilet seat having a screw sticking out of it, it's yours." I must admit, not only is he exceptionally knowledgeable, but he has a real way with words. But you can't argue with his logic.


Regardless, here are some things you should look for in an emulator, particularly if the main group using it is your power technical people.


First, it's important that the emulator runs on a variety of platforms: Windows, Mac, and various versions of Linux, particularly in our BYOD world. Restricting yourself to one platform or operating system may not be in your best interest. What platforms are you trying to support with access to the i? I know the Mac isn't a big player in the corporate world, but got anyone wanting to get in via the iPad? Platform flexibility is key.


Second, within these platforms, it's becoming increasingly important to have the emulator work on non-traditional displays: mobile, iPads, Surface, what have you. This is a follow-on to point 1 above. I don't see laptops and desktop PCs going away, but tablets and mobile devices are becoming increasingly important.


Third, it must be something that can be installed (preferably downloaded from a site) and set up very easily. The emphasis is on administration here, although setup is a factor. Without being negative, IBM i Access for Windows is probably the poster child for administrative overhead. The default path, and the easiest one to take, is to give every user every option. But do you really want everyone to be able to download or upload files? Unfortunately, customizing Access for a large number of users requires a fair amount of work.


Fourth, it should be customizablenot in the administrative sense but in terms of the keyboard and macros that can be created. You would be wrong to assume that everything maps just the way it does in IBM i Access straight out of the box. It's not wrong to be nitpicky about this.


Fifth is cost. It does vary from emulator to emulator, as do the various price points based on quantity. I believe the seat cost for IBM i Access for Windows is about $250. The seat cost for MochaSoft is about $30 with unlimited use starting at $250 – $300. And the ASNA Browser Terminal is free for up to five users.


Finally, it should be something that's supported; that's where bug fixes are applied and enhancements are made. There are some emulators out there that probably haven't been touched in years.

Two Different Types of Emulators

Truth be told, there are really three emulator flavors.


PC Installed or Fat Client


The first is our old friend, the fat client. It's a piece of software that runs on your PC. This would be stuff like IBM i Access for Windows, which runs on Windows or Linux. Or traditional Rumba or MochaSoft. In essence, this software creates an environment on your PC that can be used to display the emulation screen and connect with the IBM i.


These have a definite footprint on your machine, some larger than others. And the setup and ongoing administration work must be done separately for each user, so if you have a lot of users to deal with it can become pretty extensive.


Browser-Based or Thin Client


The second type is just beginning to emerge, and those are the browser-based emulators. An example of this is the ASNA Browser Terminal product or IBM i Access for Web. These are definitely thin-client products that leave essentially a zero footprint on the client machine and use the individual's default browser to present the IBM i session.


There's a piece of software that runs somewhere in your system, generally on a server attached to the i. On your individual machine, you then point your browser back to that server and the emulator on it and so connect to the i. There is no emulator software per se on your machine, so administration becomes much easier, although individual customization suffers.


What's so great about a browser-based emulator, especially if all it shows you is the normal green-screen? No VPN. If you use a fat client, then you probably have to sign in via a VPN. This doesn't really matter much to you, but it does to the system admin who has to support it. Going with something that can just access the browser over an SSL connection makes it easier for the administrator.




The final type is the app-based emulator. These are for devices like iPhones or iPads or what have you.


You download them from the app store, and they look like fat clients in that you use them directly to get to the i, rather than going through a browser.

So Many Possibilities

Now I know what you would like. You would like me to give you a list of every emulator out there and rank them quantitatively from best to worst. The only problem with doing that is it would be terminally boring (get it, terminally?). Plus, I would actually have to download and try each one, which would take…like forever. Besides, who am I to choose for you? You're an individual, unique; you must find your own path. Sooooo, I am just going to talk briefly about a couple of big players. But there are more, and I dare you to google "5250 Emulators" and see for yourself.


ASNA Browser Terminal 12.0


Let's start with a thin-client browser-based emulator from ASNA, the Browser Terminal 12.0


This is actually not something that ASNA started out to develop. Initially, it was developed as an emulator that was part of the ASNA Wings RPG modernization product. But it has been so popular with ASNA users that they have encouraged the company to make the emulator available separately. What's really nice for small companies is that it's free for up to five users. After that, you have to pay.


The emulator itself must run on a Windows (7, 8, or Server 2008 R2 – 2014) because it's not Java-based but .Net. But it works well with a variety of browsers on a variety of platforms, including tablets, so it can be productive in Android, Apple, and regular Windows 8 environments. Browsers that have been tested and approved are IE (9.0 and higher), Chrome, Safari, and Firefox. In this sense, it's browser-based but not an app that can be downloaded to a mobile environment. But it will run on anything that has browser, which does, of course, include phones. Make sense?


Oh, and your i has to be on 6.1 or higher.


IBM i Access


Access is a fat client. Some people would say "very fat." Turning once more to someone more knowledgeable than I am, Roger Pence of ASNA characterized it as the "Jabba the Hutt" of the emulator world. I have to admit, that made me chuckle.


At this point, some people may think I am being unfair. Well, yeah. I mean, isn't that the point of having IBM as a main vendor? To make fun of them? But I will try to act more mature. Like many things developed by IBM, it's not necessarily pretty or efficient, but it does work, it's reliable and stable (it's too big to fall over; sometimes I just can't help myself), and it offers a full set of tools to go with it (data transfer, etc.).


If you look at the IBM website for this product, it says that it's Java-based and then lists versions for Windows and Linux. Normally, when I see Java-based, I think, "Oh, this would run on the Mac," but I think in this case we're talking about server-side Java, not client-side, so it probably doesn't run on the Mac. Who cares? Well, I do, having switched from Windows to a Mac five years ago (and having to deal with my son's Windows 8 machine has cemented my resolve never to go back).


There is also, with 6.1, a new, browser-based version available, IBM i Access for the Web. I have not tried this myself, but I have heard from people who have seen demos that it looks pretty good flexible and fast. Not sure what browsers it supports, but I'm guessing at least IE.


And IBM i Access for Mobile is available as a Technology Preview, which is almost as good as actually being available. OK, I admit that was over the top; 15-yard penalty and loss of down.


Like most things IBM, getting Access is a bit complicated, and I am indebted to Richie Palma of Arbor Solutions, an IBM Business Partner, for drawing me a picture so I finally got it. You have to buy a license to IBM i Access, of courseone for each user. That will give you the ability to run a given version of Access on a given machine. In order to upgrade to a new version of the software or to transfer those licenses to a different box, you need to have a Software Maintenance agreement with IBM.


Seriously, there are a lot of good reasons for going with IBM i Access, including reliability, stability, continual upgrades, and the simplicity of using something that comes bundled with the system. Others gripe about the large footprint, the amount of admin work required if you have a large user base, and the cost. Maybe they're just people who don't like to use anything provided by "the man" (you know, rebels). And for them it's easy to find an alternative product.




Back in the day, Rumba was the big-dog emulator for those who didn't want to use Client Access. And Rumba is still around, owned by Micro Focus. It's still being enhanced and comes in several versions. The first is the classic fat-client, which runs on Windows. It comes with a full set of features and is certified for both Windows 7 and 8. The second is a browser-based version that can be used to extend Rumba down to tablet and phone devices. It's not an app, but it will run on any device that has a browser.




Another very well-known emulator is Mochasoft's TN5250 product. Mochasoft is a Danish company that's well-established in the U.S. and has been in the emulator market for a long time. This is actually the emulator that I use on the Mac, although there is some question as to how many people will want to use it just because I do. I don't see that fact listed in their marketing material.


Sometimes it seems like all people do is complain about emulators, especially the folks who have to administer them, but Mochasoft TN5250 does seem to get the best reviews. And there are many people in the i world who consider it the best fat-client emulator around.


Mochasoft has about 10 different 5250 emulator products, ranging from fat-client to browser-based (for Chrome) to apps for iPad, iPhone, Windows Phone, and WIN RT Surface.


The one drawback is that it doesn't include a database connection piece (like the ODBC driver in Access) but concentrates on the emulation aspect of the product. That's about all I ever use, so for me the ease of installation and setup plus the price (about $30 per seat or $250-$300 for unlimited company use) is hard to beat.

And in Conclusion . . .

Emulators are still out there, and as long as you're using 5250 as your display medium, they're a necessity. The field has cleared a little, but now there are more options to consider (fat client, browser, app). Think about what you need an emulator for. Look at what you're paying now. Then take a good hard look at what's out there. Seriously, just have fun with it.

David Shirey

David Shirey is president of Shirey Consulting Services, providing technical and business consulting services for the IBM i world. Among the services provided are IBM i technical support, including application design and programming services, ERP installation and support, and EDI setup and maintenance. With experience in a wide range of industries (food and beverage to electronics to hard manufacturing to drugs--the legal kind--to medical devices to fulfillment houses) and a wide range of business sizes served (from very large, like Fresh Express, to much smaller, like Labconco), SCS has the knowledge and experience to assist with your technical or business issues. You may contact Dave by email at This email address is being protected from spambots. You need JavaScript enabled to view it. or by phone at (616) 304-2466.

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