Please include your device model, iPadOS or iOS version, and the app version shown in Sidebar → Help → About.
Getting started
Open the app. The Demo (offline) configuration is ready to try. Tap Connect, enter any user ID and explore.
Add your own host: open the sidebar (swipe from the left edge or press Ctrl+,) → Sessions → Manage configurations → New profile. Enter the host, port (23 for plain connections, often 992 for TLS), TLS, TN3270E/LU and model.
Replay the guided tour anytime from Sidebar → Help → Replay.
Troubleshooting
TLS fails or shows a certificate error. Install your organization’s CA profile and enable full trust in Settings → General → About → Certificate Trust Settings. For testing only, use “Trust any certificate” in the configuration.
The host rejects the LU or device name. Check the spelling, or leave the LU blank to let the host assign one. Try turning TN3270E off for older servers.
Keyboard locked (X SYSTEM or X PROT). Press Reset (Esc, Ctrl+R or the Reset key) and move the cursor to an input field.
My keyboard has no F-keys. Turn on “F-key bar with hardware keyboard” in Sidebar → Keyboard → Input, or press Ctrl+Alt+F.
Sessions disconnect in the background. On iPadOS and iOS 26, keep “Keep sessions alive in background” on in the Display settings. The system may still end background work; Greenscreen 3270 reconnects and re-runs auto-run scripts when you return.
Finding a shortcut. Sidebar → Help → Keyboard shortcuts lists every shortcut, including your remaps.
Moving to a new device. Export your scripts and profiles and import them on the new device. Passwords are never stored, so you’ll enter them again.
Privacy
Greenscreen 3270 collects no data. Read the privacy policy.