Author: Ricky Bryce Ethernet Gateway

Ethernet Gateway

Bridging vintage hardware to modern networks

v1.0.2
Telnet SSH XMODEM CP/M Commodore 64 ANSI
Download

Version 1.0.2 — pre-built, signed binaries. Every archive also carries the README, the licence and both CP/M terminals.

Linux

macOS

  • Apple Silicon — tar.gz
  • Unsigned by Apple, so the first launch is right-click → Open, or clear the quarantine flag with xattr -d com.apple.quarantine.

Windows

  • x86-64 — zip
  • Unpack anywhere and run ethernetgateway.exe; it creates its data folder beside itself on first launch.

Every file is published with a SHA-256 sum and a keyless Sigstore signature (.sha256 and a .sigstore.json bundle) so a download can be verified with cosign verify-blob (v2.5 or newer). Older versions, the checksums and the full release notes are on the releases page; the source is on GitHub and builds with cargo build --release on rustc 1.92 or newer.

New here? The user manual (PDF) walks through the first launch, the terminal types and every setting.

About

Ethernet Gateway is a lightweight bridge that connects serial devices and legacy systems to modern TCP/IP networks.

It is a standalone, retro-themed server written in Rust. It offers telnet and SSH access to a full-featured gateway with XMODEM, XMODEM-1K, YMODEM, ZMODEM, Kermit and Punter file transfer, SSH and telnet proxying, a CP/M emulator that runs real .COM software and boots real disk images, an AI chat client, a text-mode web browser, weather reports, and Hayes-compatible modem emulation on two physically independent serial ports — each of which also flips to a telnet-serial console bridge or an always-on Kermit server on demand.

Designed to work with hardware as old as the Commodore 64 and CP/M machines while remaining fully functional on modern ANSI terminals, Ethernet Gateway adapts its display automatically to the capabilities of each connected client — PETSCII at 40 columns, ANSI in colour, or plain ASCII.

Connect & Bridge

  • Telnet and encrypted SSH access, plus SSH/telnet proxying to remote servers
  • Two independent serial ports — each a Hayes AT modem, a console bridge, or a Kermit server
  • ATDT TCP dial-out with a phone book, and peer-to-peer dialling between two devices
  • Auto-adapts to PETSCII, ANSI and ASCII terminals

Transfer & Run

  • XMODEM / XMODEM-1K / YMODEM / ZMODEM / Kermit / Punter C1
  • Gateway Shell — a CP/M-inspired A> file manager over the transfer directory
  • CP/M emulator — real CP/M 2.2 software on an emulated Z80 or 8080, plus mounting and booting .dsk images
  • CP/M printer — capture LST: output as OpenDocument or text

Scale & Manage

  • Master/Slave mode — a slave extends its serial ports to a master over SSH
  • Configure from the terminal, a browser, or the desktop console with live logs
  • Optional authentication with per-IP lockout; Ed25519 SSH host key
  • Runs on Linux, macOS and Windows, down to a Raspberry Pi
Screenshot
Ethernet Gateway GUI console

The desktop console — every setting is also reachable over telnet and from a browser.

Documentation & References

The manual, and the companion documents that go deeper than it does.

User Manual (PDF)

The whole gateway end to end: setup, terminal types, the menus, file transfer, the gateways, the modem, the config file and troubleshooting. Kept in the repository and rebuilt with every release.

CP/M Emulator Reference

The emulated Z80/8080 machine, the BDOS and BIOS services, mounting disk images, booting one, the virtual modem and the printer.

Disk Format Reference

The measured geometry of every supported .dsk format, the Altair 88-DCDD controller, sector skew and the two sector checksums.

XMODEM Protocol Reference

CRC-16 versus the older checksum, 128-byte and 1024-byte framing, block anatomy, error handling and the timeout tunables.

YMODEM Protocol Reference

What YMODEM adds over XMODEM-1K: the block-0 header, batch transfers, the end-of-batch null block and exact size-based truncation.

ZMODEM Protocol Reference

The ZDLE escape layer, hex and binary headers, CRC-16 and CRC-32, batch send and receive, resume, and the rz auto-start trigger.

Kermit Transfer Reference

Using Kermit through the gateway: client and server modes, the serial Kermit port, and what to set on the vintage end.

Kermit Protocol Reference

The protocol itself: packet types, sliding windows, long and extended packets, block-check types and 8-bit quoting.

Punter C1 Protocol Reference

The protocol Commodore terminals speak natively: dual checksums, the two-phase block transfer and the CCGMS/Novaterm handshake.

AT Command Reference

Every Hayes command the modem emulator answers, the S-registers, the result codes and the dial-out forms.

Telnet Negotiation Reference

The IAC option negotiation the gateway performs, which options it accepts, and how binary transfers survive it.

SSH Reference

The inbound SSH server and the outbound SSH gateway: host keys, public-key authentication and known-hosts handling.

Character Code Appendices

PETSCII, ASCII and control-code tables, and the ANSI escape sequences the gateway emits and filters.