IM3270 Changelog

Version history and release notes

v0.46.7

Latest 2026-04-20
Fixed
  • Windows WebSocket handshake failure (303 error): On Windows, IPv4 and IPv6 are separate bind namespaces. If another process owned IPv4 port 8080, the backend's dual-stack bind on [::]:8080 could succeed while the renderer's WebSocket hit the other server and received a 303. Also, localhost resolves to ::1 (IPv6) first on Windows — if anything squatted on ::1:8080, Chromium never tried IPv4. Backend now binds tcp4 on 127.0.0.1:8080; renderer connects to 127.0.0.1 explicitly.
  • Diagnostics flag port fallback: Both the Tools menu diagnostics (Windows) and scripts/diagnose-log.sh (Linux) now detect when the backend fell back from 8080 and show the netstat/ss command to identify the squatting process.
  • HTTP API locked to loopback: Backend's HTTP API endpoints are now bound to 127.0.0.1 only (no external access).

v0.46.6

2026-04-19
Added
  • Console Output Log: New floating panel (View > Toggle Console Output Log, Ctrl+`) with real-time color-coded connection events, errors, warnings, and transfer results. Includes interactive command bar with commands: help, diagnose, status, tabs, port, version, history, clear. Arrow keys for command history.
  • Connection diagnostics: IP typo detection warns about suspicious IPs (e.g., 192.169.x.x) before connecting. Pre-connect TCP reachability check warns if host is unreachable. Timeout error messages now include host:port.
  • Log diagnostics: Tools > Run Log Diagnostics analyzes the application log for timeouts, IP typos, startup failures, SSL errors, port conflicts, and more. Also available via diagnose command in Console Output Log or scripts/diagnose-log.sh from command line.
  • Transfer history: File transfer dialog shows a "Recent Transfers" dropdown with the last 20 transfers. Select an entry to auto-fill all form fields.
  • Automatic port selection: Backend tries port 8080 first; if occupied, the OS assigns a free port. Eliminates the "WebSocket undefined" error when another process uses port 8080.
  • SBOM in distribution: CycloneDX SBOM files now included in Linux tar.gz bundle for supply chain compliance.
Fixed
  • Login denial message not displayed: When mainframe sends a denial screen and immediately disconnects, the terminal now captures and displays the message.
  • Font size change hid terminal lines: Ctrl++/- no longer causes lines to disappear until the next keypress.
  • Install script showed wrong name: Help text in install.sh referenced the old script name.

v0.46.3

2026-04-06
Added
  • UI Scale preference: Slider in Preferences > Display (50%-150%) to scale the entire UI without affecting terminal font size
  • Help > View Application Log: Opens ~/.im3270/im3270.log in system default text editor
  • Help > Open Log Folder: Opens ~/.im3270/ directory in file manager
  • Message IDs: All log messages now use standardized IMEM prefix with unique IDs for troubleshooting
  • SBOM (Software Bill of Materials): CycloneDX SBOM files included with releases
  • Consolidated logs: Frontend and backend now write to a single log file
Fixed
  • s3270 version check failed on startup: Used single-dash instead of double-dash flag

v0.46.2

2026-04-06
Added
  • Help > View Application Log: Opens log file in system text editor (cross-platform)
  • Help > Open Log Folder: Opens ~/.im3270/ in file manager
Fixed
  • Ctrl+B / Ctrl+Shift+B shortcut conflict: Ctrl+B now correctly toggles icon toolbar, Ctrl+Shift+B toggles PF toolbar
  • PF Toolbar menu item: Added View > Toggle PF Toolbar (Ctrl+Shift+B)
  • Right-click toast to copy: Right-click any toast notification to copy the message
  • Scrollable dialogs on small screens: Connect dialog and profiles list scroll properly on laptops

v0.46.1

2026-04-05
Improved
  • SSL/TLS error reporting: SSL failures now show specific, actionable error messages instead of silently hanging
  • SSL connection dialog: Detailed tooltips on all SSL options
  • Macro Manager dialog: Responsive layout for small laptop screens
Fixed
  • Script help overlay: Added close button and Escape key to close

v0.46.0

2026-04-05
Added
  • JavaScript Scripting Engine: Full scripting system with side-by-side editor panel
  • Script Editor Side Panel: Opens alongside terminal with draggable resizer
  • Step-Through Debugger: Execute scripts line by line
  • API Command Picker: Interactive help with click-to-insert
  • Pre-Run Validation: Catches syntax errors and common mistakes before execution
  • Macro-to-Script Conversion: Convert recorded macros to editable JavaScript
  • Ctrl+Z mapped to PA2: Undo unsent typing instead of disconnecting

v0.45.0

2026-03-23
Added
  • REVEDIT editor support: MVS 3.8 RPF editor with editor-relative cursor display
  • Smart paste: Word-wraps text to fit editor data area width
  • YouTube tutorial videos: Embedded on website
  • Updated man page: New features and shortcuts documented
Fixed
  • Cursor not moving after Ctrl+C copy
  • Crosshair position after color change
  • Notepad resize on Linux
  • Update dialog close button position

v0.44.5

2026-03-16
Fixed
  • Right-Click JCL Selection: Auto-selects JCL token at click position before showing context menu; fixed coordinate alignment using xterm.js render dimensions
  • Ctrl+Shift+1-9 Copy Buffers: Fixed copy-to-buffer shortcuts (Shift changes event.key to symbols; now uses event.code)
  • Triple-Click Line Selection: In ISPF editor, triple-click now selects line text without line number prefix
  • Selection Overlay Cleanup: Single click and Escape reliably clear the yellow selection box
  • Context Menu UX: Menu appears 15px below click to not cover selected text; Escape or any keypress closes menu
  • Tab Switch Cursor Position: Cursor position in status bar now updates when switching tabs via Ctrl+Tab
Changed
  • s3270 License Compliance: Replaced "powered by" and "proven" marketing language with neutral wording per BSD 3-Clause non-endorsement clause

v0.44.4

2026-03-15
Added
  • Icon Toolbar: 17 SVG icon buttons for quick access to Connect, Disconnect, Send/Receive File, New Tab, Copy, Paste, Find, Crosshair, Keypad, Split Screen, Notepad, Timer, Editor, Macro Record, Print, and Preferences
  • State-Aware Toolbar Buttons: Buttons disable when disconnected, highlight when active, turn red when macro recording
  • Toggle Toolbar: View > Toggle Toolbar (Ctrl+B) to show/hide, preference saved across sessions
  • Edit Screen in External Editor: Toolbar button opens current screen content in vim for editing

v0.44.3

2026-02-26
Added
  • PDS Wildcard Receive (*): Enter 'DATASET(*)' in the Host File field when receiving to automatically list all PDS members with all checkboxes pre-selected
Fixed
  • About Dialog: Reduced size with max-height and scrollbar so the Close button is always accessible on smaller screens

v0.44.2

2026-02-25
Added
  • Accessibility Widget: Reusable popup widget with font size, letter/word spacing, reading mode, high contrast, and keyboard highlight controls. Persists settings via localStorage. Integrated into all 14 site pages
  • DEB/RPM Packages: Linux releases now include .deb (Debian/Ubuntu) and .rpm (Fedora/RHEL/AlmaLinux) packages alongside AppImage and tar.gz bundle
Changed
  • Free/Trial Card: Added "All PRO features for 60 days" to clarify trial benefits

v0.44.1

2026-02-25
Added
  • Free License Card: Added "Free License" ($0, 60-day trial) card to downloads and pricing sections for better trial visibility
  • Web Accessibility (WCAG 2.1): Skip navigation links, ARIA labels on nav/forms/downloads, focus-visible outlines, emoji aria-hidden, heading hierarchy fixes, table scope attributes, SVG aria-hidden, descriptive QR code alt text
Changed
  • Color Contrast (WCAG AA): Improved text contrast across all website pages
  • Pricing Grid: Widened to 3-column layout on downloads and home pages
  • Comparison Table: Renamed "Trial" column to "Free" on home page

v0.44.0

2026-02-25
Added
  • GPG Release Signing: All release artifacts are now signed with a GPG key for download verification
  • SHA256 Checksums: SHA256SUMS file generated and GPG-signed for every release
  • Install-time Verification: Linux installer optionally verifies AppImage checksum before installation
  • Security Page: New dedicated security page with verification instructions
Changed
  • Release Scripts: create-release.sh and publish-release.sh now generate and upload SHA256SUMS + GPG signature
  • Downloads & Installation Pages: Added download verification instructions

v0.43.25

2026-02-24
Added
  • Terminal Font Preference: Choose between IBM Plex Mono (modern) and IBM 3270 (classic mainframe) in Preferences
  • Bundled Fonts: IBM Plex Mono and IBM 3270 fonts shipped locally – no Google Fonts CDN dependency, works fully offline
Fixed
  • Windows character alignment: Fixed misaligned characters on startup caused by xterm.js measuring cell dimensions before fonts loaded
  • License dialog: Renamed "Activate" to "Apply", show Apply button when replacing an existing license

v0.43.23

2026-02-22
Fixed
  • LISTDS overlay on SPF/ISPF: Use TSO LISTDS prefix on all ===> prompts to clear screen before output
  • False PDS members: Filter out SPF/ISPF panel chrome lines from member name parsing
  • LISTDS command field: Added EraseEOF before typing LISTDS command to clear leftover text
  • Pre-transfer drain timeout: Increased drain deadline from 10s to 30s, fixing batch transfer timeout on slow hosts
  • s3270 error messages on screen: Prevent s3270 error text from bleeding into screen display

v0.43.22

2026-02-18
Added
  • PDS Member Browser: Browse and select PDS members from the host for batch file transfer with pagination support
  • Batch File Transfer: Transfer multiple PDS members in a single operation with progress tracking and cancel support
  • Batch Send to Host: Select multiple local files or a folder to batch-send as PDS members
  • Auto-create directories: Receive transfers automatically create the target directory if it doesn't exist
  • Demo Panels: ISPF panel and CLIST demos for displaying IM3270 product info on mainframes
Fixed
  • Batch transfer race condition: Fixed pre-transfer cleanup responses being mistaken for transfer results
  • Send file browser: Fixed file picker not showing extensionless files

v0.43.21

2026-02-10
Added
  • Notepad Panel (Ctrl+Shift+N): Floating draggable/resizable notepad for session notes. Auto-saves per host to localStorage
  • Timer / Clock Panel (Ctrl+J): Floating panel with Clock, Countdown Timer (with Tibetan singing bowl alert), and Stopwatch
  • Preferences: Show Notepad/Timer on startup, Notepad font size, Timer alert sound
Fixed
  • Ctrl+V Paste: Fixed application hang when pasting large multi-line buffers
  • Keyboard Help: Corrected swapped descriptions for End and Ctrl+End

v0.43.20

2026-02-10
Added
  • Editor-Relative Cursor Position: Status bar shows Line: N, Col: M relative to the data area when in ISPF Edit, Browse, or View. Supports ISPF action bar layout and horizontal scrolling

v0.43.19

2026-02-10
Added
  • File Transfer Dialog: Remember last used field values - fields are pre-filled with previous transfer settings when reopening the dialog

v0.43.16

2026-02-08
Fixed
  • Profile Manager: Fixed clicking a profile causing Save to update the existing profile instead of creating a new one
  • Profile Manager: Fixed auto-selecting first profile on open
  • Profile Manager: Renamed "Cancel" button to "New" for clarity

v0.43.15

2026-02-08
Fixed
  • ISPF Option 11 (Workplace) field misalignment: 2-byte UTF-8 characters (like broken bar) were not rendered, causing fields to shift left and cursor to appear one position ahead

v0.43.14

2026-01-20
Added
  • Profile Manager Keyboard Navigation: Arrow Up/Down to navigate profiles, Enter to connect, Delete to remove
  • Quick Connect Keyboard Navigation: Arrow Up/Down or Tab/Shift+Tab to navigate, Enter to connect
  • Paste to Data Area (Ctrl+Shift+V): New paste mode for ISPF editor - pastes multi-line text into data area, automatically skipping line command fields
  • Startup Diagnostic Log: Automatic logging to ~/.im3270/im3270.log - captures app startup, s3270 version check, backend status
Changed
  • Keyboard Lock Indicator: Changed "LOCKED" to "WAIT" for clearer visual feedback when waiting for host response
Fixed
  • Split Screen Focus: Fixed cursor not moving and unable to type in split tab

v0.43.13

2026-01-18
Fixed
  • Windows Backend Port Conflict: Fixed port 8080 already in use error on Windows when restarting after crash or force-close

v0.43.12

2026-01-17
Fixed
  • Keyboard Shortcuts: Changed New Tab (Ctrl+T to Ctrl+Shift+T) and Close Tab (Ctrl+W to Ctrl+Shift+Q) to avoid conflicts
  • Alt+J Selection: Fixed smart JCL selection not clearing when pressing Escape
  • Website Links: Fixed License and Privacy URLs pointing to incorrect locations
  • Profile Settings: Fixed "MM Lab" typo to "IM Lab"
Improved
  • Linux Installer: Added upgrade support - automatically removes old AppImage versions when installing new version

v0.43.11

2026-01-08
Added
  • Direct Update Download: Update dialog now downloads the appropriate installer directly for your platform instead of opening GitHub

v0.43.10

2026-01-08
Fixed
  • SDSF Block Operations: Fixed keyboard lock during block inline operations like //P - arrow keys and mouse now work correctly

v0.43.9

2026-01-08
Fixed
  • File Transfer PDS Members: Fixed file transfer truncating dataset names with parentheses like 'DATASET(MEMBER)'
  • Transfer Dialog Width: Increased host file input field width and dialog size for longer dataset names

v0.43.8

2026-01-06
Fixed
  • Rectangular Selection Copy: Fixed copy not capturing correct rows when terminal is scrolled
  • Multi-line Paste: Added proper support for pasting rectangular selections - maintains row structure
  • Clipboard Copy: Fixed race condition where selection could clear before text was copied
  • Keyboard Reference: Corrected multiple incorrect keyboard shortcuts in documentation
  • Alt+J/T/F Shortcuts: Fixed mismatch between menu accelerators and keyboard mappings
  • Linux Screen Flickering: Disabled hardware acceleration on Linux by default, batched terminal writes
Added
  • Keystroke Display toggle (Ctrl+Shift+Y) in keyboard help
  • Password Mode toggle (Ctrl+Alt+Y) in keyboard help
  • Find on Screen (Ctrl+F) in keyboard help
  • Toggle Split Orientation (Ctrl+Shift+O) in keyboard help
Changed
  • Domain Update: Changed all references from zos.co.il to im3270.infomanta.com

v0.43.7

2026-01-04
Fixed
  • Backspace Key: Fixed to use traditional PC behavior (move left + delete character)
  • Keystroke Display: Shows only "Backspace" instead of "BackSpace+Delete"

v0.43.3

2025-12-28
Added
  • Google Analytics Tag: Added tracking code for im3270-site
  • PRO Badge on Split Screen: Split Screen now marked as PRO feature throughout documentation
Changed
  • Documentation Updates: Updated all guides with Pro features and licensing information
  • License Comparison Tables: Updated to show Trial vs Personal vs Team feature differences
  • Trial Behavior Clarified: All features work for 60 days, then Pro features lock

v0.43.2

2025-12-28
Added
  • Trial Expired Dialog: Shows list of locked Pro features with link to purchase
  • Split Screen as Pro Feature: Split Screen now requires license after trial
Changed
  • Trial Expiration Behavior: Core features continue working after trial, only Pro features locked
  • Pro Features: Split Screen, Crosshair, Magnifier, Keystroke Display require license
Fixed
  • PowerShell Script: Fixed generate-license.ps1 syntax errors for Windows
  • License State: Fixed isProFeatureAvailable() to properly check trial expiration

v0.43.1

2025-12-26
Added
  • Pro Feature Restrictions: Crosshair, Magnifier, and Keystroke Display now require a valid license
  • PRO Badge: Golden badge shown in preferences for restricted features
  • Trial Status: Shows "(No support)" indicator for trial users
  • License Validation: Backend validates license keys with expiration checking
Fixed
  • Hercules Connection: Fixed intermittent connection failures with Hercules/MVS 3.8J TK5
  • Split Screen Pointer: Crosshair now follows cursor when switching between split tabs
  • Color Mapping: Fixed base color mapping for 3279 terminals
  • License Script: Fixed generate-license.sh to use "personal" instead of invalid "standard" type

v0.43.0

2025-12-25
Added
  • Keystroke Display: KeyWiz-style on-screen keystroke overlay for demos/presentations
  • s3270 Text Mode: Improved reliability with text-based s3270 communication
Changed
  • Connection Method: Uses Connect() command instead of command-line argument for better reliability
  • Wait for 3270 Mode: Added proper wait for terminal readiness before screen requests

v0.42.2

2025-12-24
Added
  • CRT Retro Effects: Scanlines, glow, and chromatic aberration effects (View menu)
  • Pointer Sonar: Visual cursor locator with Ctrl+Shift+F
  • Pointer Highlight: Persistent cursor highlight with Ctrl+H
Fixed
  • Various stability improvements

v0.42.1

2025-12-24
Fixed
  • Minor bug fixes and improvements

v0.42.0

2025-12-24
Added
  • Session Keep-alive: Configurable ping interval to prevent timeouts (Preferences)
  • Response Timeout: Configurable timeout for host responses

v0.41.0

2025-12-23
Added
  • License System: 60-day Pro trial with license key activation

v0.40.0

2025-12-22
Added
  • Macro Recording: Record and playback keystroke sequences (Ctrl+Shift+F12)
  • Play Last Macro: Ctrl+Shift+M to replay last recorded macro

v0.39.0

2025-12-21
Added
  • Split Screen: Horizontal and vertical split views (Ctrl+Shift+H/V)
  • Multiple Connections: View two sessions side by side

v0.38.0

2025-12-20
Added
  • Custom Keypad Labels: Define your own PF key labels
  • Keypad Label Styles: PF1-24, F1-24, 1-24, or custom