User Guide

1. Getting Started

IM3270 is a modern 3270 terminal emulator for connecting to IBM mainframes. It provides a feature-rich experience with split screen, macros, file transfer, and more.

Launching IM3270

• Windows: Launch from Start Menu or desktop shortcut
• Linux: Run im3270 or find in application launcher

Main Interface

• Menu Bar: Access all features (File, Edit, Connection, Transfer, View, Help)
• Tab Bar: Manage multiple terminal sessions
• Terminal Area: Main 3270 display
• Status Bar: Connection status, cursor position, keyboard state
• PF Key Toolbar: Clickable function key buttons (optional)

2. Connecting to a Mainframe

Quick Connect

1. Press Ctrl+N or select File → New Connection
2. Enter the mainframe hostname or IP address
3. Enter the port (default: 23, or 992 for SSL)
4. Optionally enter an LU name
5. Check "Use SSL/TLS" for secure connections
6. Click Connect

Terminal Models

Terminal Types

3. Keyboard Shortcuts

Function Keys

Editing & Navigation

Application

Clipboard & Selection

Paste to Data Area

Use Ctrl+Shift+V to paste multi-line text into the ISPF editor data area, automatically skipping protected line command fields. This is ideal for pasting code or JCL directly into the editor without overwriting line numbers.

4. Connection Profiles

Save your connection settings for quick access.

Creating a Profile

1. Press Ctrl+P to open Profile Manager
2. Click New Profile
3. Enter a profile name and connection details
4. Click Save

Profile Settings

• Host, port, and SSL/TLS settings
• Terminal model (2, 3, 4, or 5)
• Terminal type (IBM-3278 monochrome or IBM-3279 color)
• LU name for console connections

Terminal Type

Choose the terminal type based on your mainframe system:

• IBM-3278 (Monochrome) - Better compatibility with older systems like MVS 3.8j, Hercules, and legacy VTAM configurations
• IBM-3279 (Color) - Modern color terminal, works with most z/OS systems

Tip: If you see a blank/idle screen after connecting, try switching to IBM-3278.

5. Multiple Sessions (Tabs)

Work with multiple mainframe connections simultaneously using tabs.

6. Split Screen PRO

View two sessions side-by-side or stacked. (Requires licensed version)

Clicking on a non-active pane now properly activates it, moving the cursor and keyboard focus to that pane.

Enable Split Screen

1. Right-click a tab
2. Select Split Horizontal or Split Vertical
3. Drag the divider to resize panes

7. File Transfer

Transfer files between your computer and the mainframe using IND$FILE.

Download from Mainframe

1. Select Transfer → Download (or Ctrl+Shift+D)
2. Enter the mainframe dataset name
3. Choose local save location
4. Select transfer mode (Text or Binary)
5. Click Download

Upload to Mainframe

1. Select Transfer → Upload (or Ctrl+Shift+U)
2. Choose local file to upload
3. Enter mainframe dataset name
4. Select transfer mode and options
5. Click Upload

8. Retro CRT Mode

Experience a nostalgic look with classic CRT monitor effects.

Enable CRT Mode

Select View → CRT Mode or press Ctrl+Shift+C

CRT Effects

• Scanlines simulation
• Screen curvature
• Phosphor glow
• Subtle flicker
• Green or amber phosphor colors

9. Macros

Record and replay sequences of keystrokes for repetitive tasks.

Recording a Macro

1. Press Ctrl+M to start recording
2. Perform the actions you want to record
3. Press Ctrl+M again to stop
4. Enter a name for the macro

Playing a Macro

Press Ctrl+Shift+M and select the macro to play, or assign a keyboard shortcut.

10. Presentation Tools

IM3270 includes features designed for teaching, demos, and screen sharing.

Keystroke Display

Show pressed keys in a corner overlay - perfect for demos and training videos.

• Toggle Display: Ctrl+Shift+Y or View → Show Keystrokes
• Password Mode: Ctrl+Alt+Y - masks keystrokes as "•••" for password fields
• Shows PF keys, PA keys, Enter, Tab, and typed characters
• Combines quick typing into words
• Configure history size (3-10 items) in Preferences

Crosshair Cursor

Full-screen crosshair helps viewers follow cursor position.

• Toggle: Ctrl+Shift+X or View → Crosshair
• Customize color in Preferences

Magnifier

Zoom into any area of the screen for detailed viewing.

• Toggle: Ctrl+G or View → Magnifier
• Hover to magnify, click to lock position
• Configure size (small/medium/large) in Preferences

Pointer Sonar

Find your cursor with animated circles.

• Trigger: Ctrl+Shift+F
• Displays expanding circles around pointer

Pointer Highlight

Persistent glowing ring around pointer for screen sharing.

• Toggle: Ctrl+H
• Ring follows cursor movements

11. Preferences

Customize IM3270 to your liking via Edit → Preferences.

12. Licensing

IM3270 offers a 60-day free trial with most features. After the trial, a license key is required for continued use.

Edition Comparison

Feature	Trial	Personal	Team
Duration	60 days	Perpetual	Perpetual
Price	Free	See pricing	See pricing
Users	1	1	Up to 10
Support	No	Email	Priority
Updates	No	✓	✓
Core Features
Terminal Emulation (3278/3279)	✓	✓	✓
Multiple Sessions (Tabs)	✓	✓	✓
Connection Profiles	✓	✓	✓
File Transfer (IND$FILE)	✓	✓	✓
Macro Recording	✓	✓	✓
Custom Key Mappings	✓	✓	✓
CRT Retro Effects	✓	✓	✓
Pro Features PRO
Split Screen (Side-by-Side)	—	✓	✓
Crosshair Cursor Tracking	—	✓	✓
Magnifier (Zoomed View)	—	✓	✓
Keystroke Display (Presentations)	—	✓	✓

Activating Your License

1. Purchase a license from im3270.infomanta.com
2. You will receive a license key via email
3. In IM3270, go to Help → About
4. Click on the license status area and enter your key
5. Your license is now active

Session Logging

Record all screen output to a file via View → Session Logging. Choose Text or HTML format.

Startup Diagnostic Log

IM3270 also writes a startup diagnostic log to ~/.im3270/im3270.log which captures platform info, s3270 version check, and backend status. This log is useful for troubleshooting startup and connection issues.