Getting Started

In this tutorial you will open IMTerm, connect to an AS/400 session, navigate through a menu, and sign off cleanly. The same steps apply to z/OS (TN3270) and Linux/Unix (VT220) with minor differences noted along the way.

Open IMTerm in your browser

Navigate to the IMTerm URL provided by your administrator (for example https://imterm.company.com). If you are running locally, use http://localhost:8080.

What you should see: The IMTerm login page with an IMTerm logo, username and password fields, and a Sign In button.

Sign in

Enter the username and password given to you by your administrator, then click Sign In. You can tick Remember me to stay signed in for 30 days.

What you should see: The main IMTerm window with a terminal area and menu bar at the top. The terminal area shows a blinking cursor and "IMTerm, connecting…" or is blank.

Open the New Connection dialog

Click File in the menu bar, then New Session, or press Ctrl+N.

What you should see: The New Connection dialog with three protocol cards (TN5250, TN3270, VT220), host and port fields, and a Connect button.

Choose your protocol

Click TN5250 for AS/400 or IBM i, TN3270 for z/OS or TSO, or VT220 for Linux/Unix SSH sessions.

What you should see: The selected protocol card is highlighted in blue. The Port field updates to the default port for your chosen protocol (23 for TN5250/TN3270, 22 for VT220).

Enter the host and port

Type your server's hostname or IP address in the Host field. Confirm the port number matches your system's configuration. Leave TLS unchecked unless your administrator told you to use encrypted connections.

What you should see: The Host field shows your server address, Port shows 23 (or 992 for TLS). The Connect button is active.

Connect

Click Connect. IMTerm opens a WebSocket connection to the server and begins the TN5250/TN3270/SSH handshake. This normally takes 1-2 seconds.

What you should see: The New Connection dialog closes. The terminal area shows the host's welcome screen or Sign On panel. The OIA status bar at the bottom turns green with "Connected".

Sign on to the AS/400

On the AS/400 Sign On screen, type your User name, press Tab to move to the Password field, type your Password, then press Enter.

What you should see: The Sign On screen with the cursor in the User field. After pressing Enter you see the AS/400 Main Menu or your default menu.

Navigate to a menu option

Type the option number in the Selection or command field (the bottom input line on most AS/400 menus) and press Enter. For example, type 1 to open Work with user profiles.

What you should see: The screen transitions to the selected subsystem. The screen title in the top-right corner changes to reflect the new screen.

Navigate back

Press F3 to exit the current screen and return to the previous menu. Press F12 to cancel or go one screen back without saving. Most AS/400 screens show available F-keys in the bottom row.

What you should see: The previous menu reappears. The IMTerm PF toolbar (below the menu bar) shows the available F-keys as clickable buttons.

Sign off

From any AS/400 command line, type SIGNOFF and press Enter, or navigate back to the Main Menu and press F3. Then click File > Disconnect in IMTerm to close the session cleanly.

What you should see: The terminal shows the Sign On screen again or goes blank. The OIA status bar shows "Disconnected". Your IMTerm window remains open and ready for a new connection.