Flynn

A Telnet and Finger client for classic 68000 Macintosh systems, from the Mac Plus and up. Supports monochrome on System 6 and 256 colors on System 7. Works with MacTCP and Open Transport's MacTCP compatibility layer. Cross-compiled on Linux using Retro68.

This project was 100% built agentically using Claude Code.

Download · Features · Keyboard Shortcuts · Themes · Building · Testing · Acknowledgments · License

System 6

Telnet Session	tmux Split Panes
Connect Dialog	Multi-Session and ANSI-BBS

System 7

256-Color Multi-Session

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Download

Pre-built binaries are available on the Releases page, Macintosh Garden, and Macintosh Repository:

Edition	Description	Memory	Download
Flynn	All features — 4 sessions, 256-color themes, scrollback	~1024KB	.dsk · .hqx · .sit
Flynn Lite	Core features — 1 session, favorites, monochrome	~340KB	.dsk · .hqx · .sit
Flynn Minimal	Only essentials — 1 session, smallest footprint	~256KB	.dsk · .hqx · .sit

Each edition is available as .dsk (800K floppy image), .hqx (BinHex archive), or .sit (StuffIt 1.5.1 archive). See docs/BUILD.md for custom builds.

Requirements

• Macintosh Plus or later (4MB RAM, 68000 CPU)
• System 6.0.8 or System 7 with MacTCP or Open Transport
• ~154KB disk space, ~73KB RAM per session (mono) / ~123KB (color)

Features

Telnet & Finger

• Telnet client with full IAC negotiation, VT100/VT220/xterm terminal emulation, ANSI-BBS mode with CP437 rendering, and OSC sequences (window title, palette/color queries)
• Finger client (RFC 1288) with user queries, verbose mode, and forwarding
• Up to 4 simultaneous sessions in resizable windows with 192-line scrollback
• Bookmarks with per-bookmark protocol, font, terminal type, and theme

Display

• 256-color support on System 7 with Color QuickDraw
• 11 built-in color themes plus Ghostty-format theme import/export
• UTF-8 with box-drawing, Unicode glyphs, emoji, and Braille patterns
• 8 fonts (Monaco, Geneva, Chicago, Courier, New York, Helvetica, Times, Palatino) in 4 sizes

Input

• M0110 keyboard support — full mappings for Escape, Control, and function keys
• Mouse text selection with copy, paste, Select All, and bracketed paste mode
• Find in Scrollback (Cmd+F / Cmd+G) and session logging (Cmd+L)

System Integration

• System 6.0.8 through 7.5.5 — MacTCP and Open Transport compatibility
• System 7 enhancements: movable modal dialogs, Apple Events, telnet:// URL handling
• Persistent settings, window position, and Preferences folder support
• Aligned with Apple Human Interface Guidelines

Keyboard Shortcuts

Flynn is designed for the Apple M0110/M0110A keyboard, which lacks Escape and Control keys. These mappings also work on modern USB/ADB keyboards.

Action	Keys	Notes
Escape	Cmd+.	Classic Mac "Cancel" convention
Escape	Clear (keypad)	M0110A numeric keypad key
Escape	Esc key	Modern keyboards only (not on M0110)
Ctrl+key	Option+key	e.g., Option+C = Ctrl+C
Scroll up/down	Cmd+Up/Down	One line at a time
Scroll page	Cmd+Shift+Up/Down	One page at a time
Select text	Click+drag	Stream selection with inverse video
Select word	Double-click	Selects contiguous non-space word
Extend selection	Shift+click	Extends selection to click point
Copy	Cmd+C	Copies selection, or full screen if none
Paste	Cmd+V	Sends clipboard to connection
Select All	Cmd+A	Selects entire terminal screen
F1-F10	Cmd+1..0	For M0110 keyboards without function keys
Find	Cmd+F	Search scrollback and screen
Find Again	Cmd+G	Repeat last search
Show Clipboard	Cmd+K	Show clipboard viewer window
Reset Terminal	Cmd+E	Clear screen and reset parser state
Bookmarks	Cmd+B	Open bookmark manager
Add Favorite	Cmd+D	Save current session as bookmark
Finger	Cmd+I	Finger protocol query
New Session	Cmd+N	New session (new window if connected)
Reconnect	Cmd+R	Reconnect to same host after disconnect
Start/Stop Logging	Cmd+L	Log session output to text file
Print	Cmd+P	Print scrollback and screen content
Save Contents	Cmd+S	Save scrollback and screen to text file
Close Window	Cmd+W	Close active session window
Quit	Cmd+Q	Quit Flynn

Themes

Flynn ships with 11 built-in themes selectable from Options > Theme:

Theme	Type	Description
Light	Mono	Black on white, default. Works on all systems.
Dark	Mono	White on black. Works on all systems.
Solarized Light / Dark	Color	Ethan Schoonover's Solarized palette.
TokyoNight Day / TokyoNight	Color	Based on the Tokyo Night color scheme.
Amber CRT	Color	Amber phosphor CRT aesthetic.
System 7	Color	Macintosh System 7 CLUT palette.
Compact Mac	Color	P7 phosphor warmth (Mac Plus/SE/Classic).
Dracula	Color	Dark purple-accented palette.
Nord	Color	Arctic blue-tinted palette.

Mono themes work on all systems including the Mac Plus. Color themes require a Mac II or later with Color QuickDraw (detected automatically at runtime). Up to 4 additional custom themes can be imported from Ghostty-format files (Options > Theme > Import Theme).

To create custom themes or learn how the theme engine works, see the full Theme Guide.

Building

Requires the Retro68 cross-compilation toolchain. Build it from source (68k only):

git clone https://github.com/autc04/Retro68.git
cd Retro68 && git submodule update --init && cd ..
mkdir Retro68-build && cd Retro68-build
bash ../Retro68/build-toolchain.bash --no-ppc --no-carbon --prefix=$(pwd)/toolchain

Then build Flynn:

./scripts/build.sh

Build Presets

Flynn supports fully customizable builds. Three presets cover common configurations:

Preset	Sessions	Features	Memory
full	4	all features	~1024KB
lite	1	core features	~340KB
minimal	1	only essentials	~256KB

The default build uses the full preset. Select a preset with --preset:

./scripts/build.sh --preset minimal    # stripped, for 1MB Macs
./scripts/build.sh --preset full       # everything, 4 sessions

Individual features can be toggled with --feature / --no-feature flags. Presets are applied first, then individual flags override:

./scripts/build.sh --preset minimal --finger --bookmarks
./scripts/build.sh --sessions 2 --color --no-darkmode

See docs/BUILD.md for the complete list of build flags, feature details, memory costs, and examples.

Testing

Uses Snow emulator (v1.3.1) with a Mac Plus ROM and System 6.0.8 SCSI hard drive image. Snow supports DaynaPORT SCSI/Link Ethernet emulation for MacTCP networking. The emulator can be fully automated via X11 for unattended testing. See docs/TESTING.md for details.

Acknowledgments

• Claude Code by Anthropic
• Retro68 by Wolfgang Thaller
• Snow emulator
• wallops by joshua stein — MacTCP wrapper (tcp.c/tcp.h), DNS resolution (dnr.c/dnr.h), utility functions (util.c/util.h), and MacTCP.h are used directly from this project. ISC license.
• subtext by joshua stein — The Telnet IAC protocol implementation (telnet.c/telnet.h) served as the reference for Flynn's client-side telnet engine. ISC license.

License

ISC License. See LICENSE for full details.

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Note: The GitHub repository is a read-only mirror. Please open issues and pull requests on Codeberg.