Apple II Terminal for Claude Code

A real Apple II, as a terminal for Claude Code.

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Boot a 140K floppy, dial a WiFi modem, and your Apple II becomes a terminal for the real claude CLI, bridged from a modern machine. The disk image is bootable on every model from the IIgs down to the II+ (or in an emulator).

It's not a chat toy. The backend is the actual agentic Claude Code, and the clients are bare-metal 65816 and 6502 that draw the whole UI themselves from a tiny 7-bit ASCII protocol. A IIgs gets a Super Hi-Res client with an animated splash, scrolling transcript, and thinking spinner; a IIe, IIc, IIc Plus, or II+ gets a text-mode client.

Press Connect and it plays the 1986 dial-up soundscape: dial tone, touch-tones that spell C-L-A-U-D-E on the keypad, ring, and answer tone.

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Apple II instructions

Prerequisites:

1. An Apple II (IIgs down to the II+ — see docs/COMPATIBILITY.md for the tested-model matrix)
2. A Hayes-compatible modem (or modem emulator like the WiModem 232 Pro) OR a serial connection to your modern Mac.
3. FloppyEmu or some way of writing a .dsk image to a floppy disk
4. Claude Code installed and logged in on your modern Mac
5. The CLAUDE.dsk disk image, from Releases (or built from source, below)

Setup:

1. Bridge, on the machine with the claude CLI:

   git clone https://github.com/wr/apple-ii-terminal-for-claude-code
   cd apple-ii-terminal-for-claude-code
   python3 ./bridge/bridge.py --telnet --app --backend code --workdir ~/your-project
   

   Setup	Python install
   TCP/emulator + --backend code	None; install and log in to the external claude CLI
   Serial + --backend code	python3 -m pip install -r bridge/requirements-serial.txt
   Any transport + --backend chat	python3 -m pip install -r bridge/requirements-chat.txt and set ANTHROPIC_API_KEY
   Every optional bridge feature	python3 -m pip install -r bridge/requirements.txt

   It listens on TCP 6400. When an unpaired source IP first needs access, the bridge creates a 6-character code and prints it only on its own console. A native client exchanges the code for a private token and presents it on later connects. The 8-bit client persists that token on its boot disk across reboots; the IIgs client keeps it only in RAM for the current boot. A valid-token reconnect does not print a code. The generated code is discarded after a successful pairing, but an intercepted unused code can still be replayed from the same source IP. --workdir is the project Claude Code works in — in code mode it reads and writes files and runs commands in that directory, so point it at the repo you actually want on the wire.

   Trusted LAN only. --telnet exposes a Claude session (in code mode, a shell on the host) to your network. Telnet is plaintext: anyone who captures LAN traffic may be able to replay a pairing code or token. Run it only on a home LAN you trust, and never port-forward it or bind it to a public interface. See pairing flags to set a shared code or revoke access.

   What the bridge records. Every prompt you type from the Apple II prints to the bridge's own console; replies are logged as metadata, not text. The pairing store records each token's SHA-256, first-seen IP, and pairing time at $XDG_CONFIG_HOME/claude-ii-terminal/paired.json, or ~/.config/claude-ii-terminal/paired.json when XDG is unset. It never stores the plaintext token. The 8-bit client keeps that token on disk; the IIgs client retains it only in RAM until reboot. Full picture in SECURITY.md.

2. Modem: store the bridge's address as phone book entry 0, then save:

   AT&Z0=192.168.1.50:6400      (your host's LAN IP)
   AT&W
   

   Your specific modem may require different commands. Feel free to open a GitHub issue if you want to contribute instructions for your specific hardware.

   Connect on the boot menu dials entry 0. The menu also has a live Hayes AT console for whatever your modem needs. Cables, per-device commands (a fresh WiModem ships at 300 baud and wants AT*B9600 once), and a "modem plays dead" checklist are in docs/MODEM-SETUP.md.

3. Disk: copy CLAUDE.dsk to a FloppyEmu SD card (5.25" mode, boots from slot 6). On a Mac, tools/install-sd.sh does it safely; FloppyEmu is very sensitive to FAT32 fragmentation, and macOS fragments more than you'd expect. If a card is already fragmented, tools/install-sd.sh repair fixes it. Create backups before using!

4. Power on and pick Connect from the menu. With any luck, it should connect to the bridge automatically!

To update later, download the new release image and re-run install-sd.sh; it overwrites the existing image in place.

Emulator instructions

I used KEGS, but any Apple II emulator with serial emulation should work. (KEGS needs an Apple IIgs ROM file you supply — see the KEGS docs.)

1. Download CLAUDE.dsk from Releases.

2. In KEGS, press F4: set s6d1 to CLAUDE.dsk, and set Serial Port Slot 2 to Incoming (KEGS then listens on TCP 6502).

3. Start the bridge, then reboot the emulator with Ctrl-⌘-Reset:

   git clone https://github.com/wr/apple-ii-terminal-for-claude-code
   cd apple-ii-terminal-for-claude-code/bridge
   python3 bridge.py --connect 127.0.0.1:6502 --app --backend code --workdir ~/your-project
   

4. On the boot menu pick 1. Connect, then type. --workdir is the project Claude works in.

Advanced bridge options

The bridge is one Python script. Pick a transport, a backend, and (for the native clients) --app. Two commands cover almost everything:

# Emulator (KEGS in Incoming mode):
python3 bridge.py --connect 127.0.0.1:6502 --app --backend code --workdir ~/project

# Real hardware (WiFi modem listening):
python3 bridge.py --telnet --app --backend code --workdir ~/project

Transport (choose one):

Backend:

Native client:

Pairing (telnet only):

Run python3 bridge.py --help for the rest (flow control, pacing, telnet negotiation, permission mode).

Generic terminal app instructions

Run the bridge without --app and it speaks ordinary 40/80-column text, so any Apple II with a terminal program, or a stock IIc using the firmware's built-in terminal over a serial cable, can talk to Claude with nothing installed on the II. Wiring, pinouts, and per-machine settings are in apple2/TERMINAL-SETUP.md.

Claude slash commands

Slash commands from the II: the bridge handles /help, /new or /clear, /mode chat|code, /model NAME, and /quit or /exit. In code mode everything else passes through to the CLI, so /cost, /context, /compact, and your installed skills run for real. Ctrl-C interrupts a reply mid-think (the bridge kills the turn and sends what it has); pressed at an idle prompt it quits to the menu.

Building from source

You don't need this to run it; the release disk is prebuilt. To hack on it you need cc65 (brew install cc65), dos33fsprogs (built anywhere, point DOS33FSPROGS at it), and Python 3 with requirements-build.txt installed.

python3 -m pip install -r requirements-build.txt
cd apple2gs && ./build.sh                                    # both clients into one CLAUDE.dsk
python3 preview.py assets.inc out.png                         # render the SHR screen, no emulator

build.sh starts from a pristine Apple DOS 3.3 System Master and injects both clients plus a machine-detecting HELLO; that master-based image is the one proven to boot KEGS, FloppyEmu, and real drives alike. The master is vendored at apple2gs/dos33-master-jan83.dsk (the January 1983 System Master, 143,360 bytes), so a clean checkout builds with nothing to fetch. It's Apple's OS, not ours; see THIRD-PARTY-NOTICES.md. Verify it:

shasum -a 256 apple2gs/dos33-master-jan83.dsk
# 70986935d95c4a918852700364ac107607eb861a7d93a69c2b5caf44a696b17a

Everything else is generated at build time: the font from unscii, the splash animation machine-ported from a gif, the sounds from tone tables in gen_assets.py. Provenance for the bundled material is in THIRD-PARTY-NOTICES.md.

The 8-bit client has its own harness: MAME with an emulated Super Serial Card mapped to a TCP socket, driven by Lua-scripted keystrokes, so the whole boot → dial → session → reply loop runs unattended.

Credits

This project is not affiliated with or endorsed by Anthropic. This is a fan project that gives their excellent CLI a 1986 terminal for fun. "Claude" and the Clawd mascot are Anthropic's.

• Font: unscii (CC0)
• Disk tooling: dos33fsprogs by Vince Weaver.
• Emulator: KEGS.
• The Apple II community... Apple II forever!

MIT license, covering this project's own code only. The build and the release disk also include third-party material (Apple's DOS 3.3, the Clawd art, the unscii font); provenance and status for each is in THIRD-PARTY-NOTICES.md.