The IBM i System (aka i5 aka iSeries aka AS/400) uses something called 5250 to stream its data to a terminal, often called a green screen. You’ve seen this clunk old terminals in black and white scifi movies – well we still use them. Kind of. But we use a terminal emulators (software which emulates the functions of those old terminals) to type commands into a command line interface using windows/linux/mac whatever.
If you are trying to connect to an i5-iSeries-AS/400, you probably want a telnet client that handles 5250. This is called a TN5250 client.
Before we get the to the free stuff
My 5250 Emulator of choice is Mochasoft
This is a commercial product but looks nice and I’ve used it for years. It works with every version of windows and does exactly what it says on the tin. It’s lightweight and simple to use so checkout (https://www.mochasoft.dk) for their TN5250 client. At time of writing it is $25 per client.Me. Just Now.
Having said that – We all love free stuff right?
Free 5250 Emulator
Sourceforge has a true open-source, freeware TN5250. You can download it and learn more at tn5250.sourceforge.net It is small (less than 1 mb) and installs very quickly…. and it’s #free.
I suggest two configuration changes to make:
After installation, you should have a desktop icon named TN5250.
Right-click on that icon and then click on properties. Add the characters
Now we can create a config.file to store our most used connection info. Use the MS-DOS editor to create a new ﬁle called tn5250rc by typing:
Set all of your TN5250 options in this ﬁle. For example, if you wanted to create a display called FRED1 which
connects to an as400 called iseries.sample.com, you’d type this:
host = iseries.sample.com
Now that you’ve created this, you can utilize those settings just by typing: tn5250 profile1
Be careful of capitalization. “proﬁle1” is not the same as “Proﬁle1” and that’s different from “PROFILE1”.
You can set any of tn5250’s settings in the tn5250rc ﬁle. Here’s a more sophisticated example:
host = ssl:iseries.sample.com
host = ssl:as400.example.com
host = ssl:as400.example.com
env.IBMMFRTYPMDL = *HP4
env.IBMMSGQNAME = QSYSOPR
env.IBMMSGQLIB = *LIBL
(that is an underscore chracter between “+resize” and “fonts”) This will allow you to resize the window.
In the folder “Program Files” in the sub-folder “TN5250” is a file named “TN5250rc”. (C:\Program Files (x86)\TN5250)
Change it (one way is to right-click, selct open-with and select notepad or Wordpad)
Make it look something like this:
(Instead of 192.168.0.1, enter your host ID or TCP/IP address)
The font_80 line changes the font to MS Gothic and the 12×24 defines the width and height of the window. Change those until the window is the size that you like.
That’s it. Double-click the TN5250 icon and you should see an i5-iSeries-AS/400 display terminal session.
This application is very full-featured. It also includes a Linux version.
Go to TN5250.sourceforge.net to learn more.
Some other TN5250 products you might like to look at: