The Big Picture

  • IBM Z is a family of IBM mainframe computers
  • 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
While the 2019 contest focus is on underlying z/OS components critical to supporting and maintaining
the environment, IBM Z and z/OS is much more with a rich set of capabilities that include:

  • Open source technologies
  • Cloud technologies
  • APIs to web enable any IBM Z business services
  • Advanced security and encryption
  • etc.

2020 contest plans are to showcase a few recent IBM Z advancements, such as the recently announced:

If curious about other IBM Z operating systems, then visit:
IBM Z IT infrastructure operating systems

Connection Details:

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.

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


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.

Please take the time to validate communication path to contest system.

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

Install TN3270 and SSH software for your workstation's operating system:
Windows, Mac, or Linux

Click twisty at left to expand a section
Software installation instructions section

Click above twisty to collapse a section

Windows TN3270

Installation and Connection

Select 1 of the following 3270 options:

  • Option #1 - Vista tn3270

    Tom Brennan Software is providing their tn3270 client along with licensing to all contestants of the Master the Mainframe contest.
    Click on link below, download, and install Vista V1.27:

    Check the email from the IBM Master the Mainframe Contest team for the license key that allows extended academic use of Vista tn3270.

  • Option #2 - wc3270
      Select Windows Setup .EXEs 3.6ga6
       wc3270 documentation
    *NOTE: Windows 10 only - Windows 7 may fail to work properly

Mac TN3270

Installation and Connection

Select 1 of the following 3270 options:

  • Option #1 - 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.
    MacOS Catalina Users - The latest MacOS update drops support for 32 bit apps, which includes tn3270. Please proceed to the x3270 instructions below
  • Option #2 - x3270 Client Installation
    Review Instructions here: http://planetmvs.com/mvsintosh/x3270.html

    -or- use this install_c3270 script to automate the process (requires sudo access)

    NOTE - For the compile step, use
    ./configure --enable-c3270
    This will build the c3270 binary, which can be used without an X11 environment.

Linux TN3270

Installation and Connection

  • 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.

Windows SSH

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

Linux SSH

Linux SSH

  • OpenSSH is installed by default into Linux.
    Test by opening a local terminal session and entering the command ssh.

Next: Connection Instructions

Connection Instructions
ID and Password:
  • Your assigned ID and password are included in the registration confirmation email
  • All IDs are activated on opening day of contest
  • Password issues after open day
  • 3 failed password attempts result in revoked ID
  • Self service password reset application is available
  • Use Master the Mainframe Slack Workspace to reset password
    Password Reset Instructions

Instructions for TN3270 connection to z/OS

Windows Vista TN3270 connection instructions
  • Using 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
    Observe IP address was entered and Terminal Model - Mod 4 was selected

    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

Windows wc3270 connection instructions

Launch the Wizard and enter 1 to Create a new session

Enter a unique session name, such as MtM

Enter as Host Name

Observe the Options which can be changed

To accept all default Options, enter to proceed

Enter Y to create session file and Y to create desktop shortcut

Now a shortcut icon appears on workstation desktop

Enter 8 to Quit

Note: Right click at top of wc3270 session - select properties to increase screen and font size

Linux x3270 connection instructions
  • 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.

MAC 3270 connection instructions
  • 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!

  • The initial password must be changed during TSO/ISPF logon using a TN3270 session
  • Using SSH for initial z/OS access will fail due to SSH inability to change initial password
  • SSH password is the new password selected during TN3270 logon

Instructions for SSH connection to z/OS

Windows SSH client

Use your personal ID and password established during TN3270 connection for SSH ID and password

The password needs to be entered in lowercase

Option #1

Your Windows may have SSH available using the command prompt as follows:

First SSH attempt requires yes response to accept connection fingerprint

Successfully logon displays z/OS Unix command prompt as follows:

Option #2

If Windows is without SSH command, then use PuTTY

Enter IP address in Host Name (or IP address) box as shown:

Example Saved Sessions name is MtM, then Save, Load, and Open at bottom

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

Enter your personal ID and same password (lowercase) used for TN3270 logon as shown:

Successful logon display follows:

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.

The z##### after SSH command is informing SSH Server the ID to be used to authenticate.

You will be greeted with the following screen.

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

MAC SSH client

From MAC command prompt, enter SSH command as shown in the Windows and Linux examples

Next: Part One - Readme