Preparation Guide

The Big Picture

  • IBM Z is a family of mainframe computer hardware
  • IBM Z is capable of hosting five unique Operating systems
  • IBM Z is capable of concurrently running thousands of Operating systems on a single mainframe
  • z/OS is the IBM Z flagship Operating system and the primary focus of the contest challenges
  • IBM Z manages business critical data

If curious about other IBM Z Operating systems, then visit:
IBM Z IT Infrastructure Operating systems

While z/OS has many connection services, you are only required to connect to 2 services during the contest.
Each connection service uses the same IP Address but different Port numbers.

If unable to connect from school campus, try from home. You or a faculty member may need to communicate
the following information to your school campus network administrator to ensure the following IP address
and port numbers are allowed to be accessed from the school campus network.

Connection Details:

z/OS IP Address:
Service Port
TN3270 23
SSH 22
FTP (Optional) 21
IDz (Optional) 4035 and 6715
Db2 (Optional) 5040

Please take the time to validate communication path.
From workstation command prompt:

If ping is successful, then proceed to Next: Required Workstation Software

If ping is unsuccessful, then contact local network administrator.
When contacting network administrator, pass along IP address and above Port numbers.
Workstation or network firewall software can block IP addresses and Port numbers needed to participate in this contest.

Note: During a regularly scheduled interval, the IBM Z development lab that hosts the Master the Mainframe contest is unavailable from approximately 9:30am to 3:30pm every other Sunday in central USA time zone.

Next: Required Workstation Software

Required Workstation Software
Preparation Guide

The contestant must install various software depending on the workstation's operating system. Please see the section below that corresponds to your workstation.


The following software is required for contestants running Linux workstations:

  • x3270

    Refer to your respective Linux workstation distribution's repository to acquire and install x3270. If you are unsure of what the previous sentence means, use your favorite search engine to search for something like “Ubuntu 16.04 x3270 installation” or “Fedora 24 x3270 installation”. Once installed, you can open the 3270 emulator from the local terminal by entering the command x3270 or by searching the application menu.

  • OpenSSH

    In general, OpenSSH is installed by default into Linux. Test this by opening a local terminal session and entering the command ssh.


The following software is required for contestants running Mac workstations:

  • tn3270

    Option #1 - x3270 Client Installation

    Review Instructions here: http://planetmvs.com/mvsintosh/x3270.html

    Option #2 - Brown University provides a tn3270 client that is freely-licensed for non-commercial use.

    Download it from here: http://www.brown.edu/cis/tn3270/

    Select the tn3270 release that supports your OS X version. Most Mac users will select the latest 3.4.0 release as it supports OS X 10.3.9 and later.

  • OpenSSH

    In general, OpenSSH is installed by default into Mac OS X. Test this by opening a local terminal session and entering the command ssh.


The following software is required for contestants running Windows workstations:

Next: Connection Instructions

Connection Instructions
Preparation Guide
ID and Password

Try to connect now prior to opening day of the contest.

ID is sent after registration and before contest begins.

Password is available in the instructions on opening day of the contest.

Instructions below include connecting to z/OS using:

  1. TN3270 (TSO/ISPF)
  2. SSH (Unix Services Shell Prompt)

Connecting to z/OS TN3270 when Workstation is Linux

  • Use Linux x3270

    To connect to z/OS TN3270 (TSO, ISPF, etc) from a Linux workstation x3270 client, first start the client.

    From a console command line, run “x3270”. This opens a new x3270 session window.

    Ensure that your client is set to "Model 4". Click Options -> Screen Size -> Model 4 (80x43).

    Click Connect at the top and in the "Enter Hostname" box, type in IP address for z/OS.

    Linux workstation x3270 client

    Then click Connect.

    At this point, you can rest assured that the connectivity to z/OS is functioning properly.
    Refer to the Part One challenge documentation for instructions on how to log onto z/OS.

Connecting to z/OS TN3270 when Workstation is a MAC

  • Option #1 - Brown University tn3270

    Thanks to Brown University: Download and Install Brown tn3270 for MAC

    Navigate to the folder that contains the tn3270 software and double-click the tn3270 X icon to start tn3270.
    You may see a prompt about the application being downloaded from the internet.
    Select Open.

  • Option #2 - x3270

    Thanks to our IT professional friend, David, at PlanetMVS:
    Download and Install x3270 for MAC
    from http://planetmvs.com/mvsintosh/x3270.html

    In the new window, enter the IP address for the contest z/OS system as the hostname and a Window Title of your choosing.

    IP Address in example below must be replaced with

    Click on "Screen Format" and set the "Large Screen Size:" option to 43x80 (Model 4). Then click Okay.

    Select Open Connection. It may take a few seconds for the z/OS or z/VM welcome screen to appear.
    Once you see this screen, congratulations, you are connected!

Connecting to z/OS TN3270 when Workstation is Windows

  • Use Vista TN3270

    If this is your first time using Vista TN3270,
    Start Vista TN3270 and click File -> New Session Ask
    If you have used the Vista TN3270 software before, you will automatically be brought to the Vista TN3270 - Start a New Terminal Session window.

    Alternatively, overtype tn3270.mycompany.com with as shown below

    Click Connect. Once you see the following screen, you've successfully connected to z/OS.

  • Configuring Vista TN3270 for Model 4 (Mod 4)

    To change Vista TN3270 to a model 4 display, click Options -> Options.

    Next, select the Display tab at the top and click the Mod 4 radio button. Mod 4 enlarges the display to 43 Rows by 80 Columns from the Mod 2 default of 24 rows by 80 columns.

    After clicking Okay, Vista TN3270 should prompt you for a reconnect. Click OK.

    Once logged back into z/OS, you'll note the screen resolution has increased.

  • Vista TN3270 Keyboard and Keypad

    To change Vista TN3270 Keyboard, click icon as shown in picture below.
    To use the Vista TN3270 Keypad, click icon as shown in picture below

Connecting to z/OS SSH when Workstation is Linux

  • Use Linux ssh client

    From a local terminal, run the command ssh z#####@
    The first time you connect you will be prompted to verify the authenticity of the host. Enter “yes” to continue connecting.

    You will be greeted with the following screen.

    At this point, you can rest assured that SSH connectivity to z/OS is functioning properly.

Connecting to z/OS SSH when Workstation is a MAC

  • Use MAC ssh client

    Use the same instructions as to connect from Linux; these should work in Mac.

Connecting to z/OS SSH when Workstation is Windows

  • Use PuTTY

    After starting PuTTY, enter the IP address of the contest z/OS system in the Host Name (or IP address) box.
    Ensure that the port is set to 22 and the SSH option is selected.
    Then enter MTM-Unix (or a description of your choosing) in the Saved Sessions box and click Save.

    The next time you start PuTTY, you can just double click the newly created Saved Session "MTM-Unix" to quickly reconnect.

    Click on the Open button at the bottom.

    The first time you connect to z/OS Unix, you will be see a Security Alert. Click Yes to continue.

    Enter USERID at the 'login as:' prompt to test the connection.

    If you are prompted for a password, you are ready to connect to the z/OS USS contest environment. Well done!

During Part One of the contest, the initial password is changed during TSO/ISPF logon.
The same password used to logon to TSO/ISPF, must be used to authenticate to Unix System Services via SSH.

Next: Part One - Welcome