ATDT IRC / CHAT
IRC client
Join IRC from an 80×24 vintage terminal. TLS, channels, private messages, /ME, /WHOIS and unread indicators are built in.
Free Windows utility · Current public release v3.6
Serial / RS-232 / FujiNet / Telnet
RetroModem Bridge
RetroModem Bridge turns a Windows PC into a Hayes-compatible modem for older computers. Use ATDT in your usual terminal to dial Telnet BBSes or open RMB's built-in local BBS, ANSI art collection, IRC client and door games. It also accepts network connections from FujiNet.
Free, open-source, self-contained Windows 10/11 x64 ZIP. No installer. Downloads are provided only on RetroModemBridge.com.
Current releasev3.6
Windows10 / 11 · x64
DistributionSelf-contained ZIP
LicenseFree · MIT open source
Connection
How it connects
The vintage computer stays a serial terminal. It does not need its own TCP/IP or Wi-Fi software.
01CoCo 3NetMate or another terminal program
02Deluxe RS-232 PakSerial interface on the old computer
03Serial + USB adapterNull-modem cable and Windows COM port
04Windows PC + RMBHandles Hayes commands and the Telnet socket
05DestinationTelnet BBS, local menu, IRC, ANSI art or a door game
Example: CoCo 3 with a Deluxe RS-232 Pak and NetMate. Other serial-capable computers work similarly. FujiNet clients can skip the serial cable and connect to the built-in TCP listener (default port 2323, UDP discovery on 2324).
New in v3.6
IRC, ANSI art and plugins
Version 3.6 adds services you can open directly from the vintage keyboard. The screenshots below are from the current release.
ATDT ANSI / ART
ANSI Art Library
Browse scene artpacks by year and file, or view your own local .ANS files. Art is downloaded as needed and cached.
PLUGIN API 1
Plugin Manager
Plugins live in the Plugins folder. Enable, disable and configure each service from the Windows app.
The rest of the program
What RMB does
The core serial bridge and directory tools are still there, alongside the new v3.6 features.
Hayes-style dialing
AT, ATI, ATDT, ATDL and ATH. Dial a saved alias or any host:port; RMB handles the Telnet connection.
Network listener
Run a TCP listener for FujiNet alongside the serial bridge or by itself. Default listener port is 2323; UDP discovery uses 2324.
13-option ANSI menu
Use ATDT MENU to browse local services, BBS lists, Favorites, dial history, door games, art and IRC from the old computer.
1,000+ BBS listings
The Telnet BBS Guide is included. Search, import, update, test and dial entries without having to remember hostnames.
Local Door Games (experimental)
Set up a compatible Windows door with an alias. RMB generates DOOR32.SYS and handles optional input and paging assistance.
Redesigned interface
Dark UI, modem status lights, a separate Favorites tab, serial and network controls, and a Hang up button that sends NO CARRIER.
Session Mirror
See the same ANSI session that appears on your vintage screen and optionally type into it from the Windows PC.
Built-in ANSI terminal
Open and test BBS connections from Windows, with live logs, traffic counters and connection status for troubleshooting.
Hardware profiles
Save COM port, baud rate and control-line settings for different computers. There's also a first-run setup checklist and support-bundle export.
From your vintage terminal
Commands
These are sent to RMB by your terminal software, not entered in the Windows application.
Quick test
Use the same commands you would send to a modem.
After starting the bridge, type AT. If RMB returns OK, the serial side is responding. Then open the menu or dial an existing saved BBS alias.
AT
OK
ATDT MENU
ATDT BBSLIST
ATDT IRC
ATDT ANSI| Command | Purpose |
|---|---|
AT | Check whether RMB is responding. |
ATDT HOST:PORT | Dial a Telnet system directly. |
ATDT MENU | Open RMB's local ANSI main menu. |
ATDT BBSLIST | Browse the saved BBS directory. |
ATDT IRC
ATDT ANSI | List favorite BBS entries. |
ATDT GUIDE | Browse imported Telnet BBS Guide listings. |
ATDT UPDATE | Update the Telnet BBS Guide. |
ATDT IRC / CHAT | Open the v3.6 IRC client. |
ATDT ANSI / ART | Open the ANSI Art Library. |
ATDT DOORS | Show configured local door games. |
ATDT USURPER | Example: launch a configured door alias. |
ATDT TIME | Show the Windows PC's local time. |
ATDL | Redial the last destination. |
ATH | Hang up the current connection. |
Screenshots from the official website
RetroModem Bridge v3.6
These are the current screenshots on RetroModemBridge.com, including the new plugin features, local BBS and real CoCo 3 hardware. Click to enlarge.
Serial controls, modem lights, directory and live log in the redesigned Windows interface.
The 13-option local BBS menu, available with ATDT MENU.
Full-screen 80×24 IRC client with TLS and channel management.
View text-mode artpacks and your own local ANSI artwork.
Enable or configure the ANSI Art Library and IRC Client.
Monitor what the vintage terminal is displaying.
Import, filter and browse entries from the Telnet BBS Guide.
Door Games list in the Windows app.
Set executable, alias, arguments and paging options.
ANSI art displayed on a real Tandy CoCo 3 monitor.
A local Windows door game played on real CoCo 3 hardware.
Hang up a running call from Windows; the retro terminal receives NO CARRIER.
Images are served from the official RetroModemBridge.com website; updated source screenshots will appear here without duplicating binary files.
Getting started
Setup & requirements
Start with the serial connection. If you see garbage characters or don't receive OK, check your port configuration before investigating Telnet.
Basic setup
- Connect the hardware. Connect the vintage computer's RS-232 interface to your Windows PC. A USB-to-serial adapter is commonly used.
- Configure RMB. Select the correct COM port and baud rate. The vintage terminal must use matching serial settings.
- Start Bridge. Open your terminal software on the vintage machine once RMB is ready.
- Test and dial. Enter
AT, check forOK, then tryATDT MENUor a saved BBS alias.
What you need
- Modern PCWindows 10 or 11 (64-bit). The v3.6 release is a self-contained ZIP; no extra .NET installation is required.
- Vintage computerA serial connection and terminal software, or a supported FujiNet network connection. RMB is not limited to the CoCo 3.
- Matching serial configurationBaud rate, data bits, parity, stop bits and flow control must agree between both sides.
- SoftwareRetroModem Bridge v3.6 is free under the MIT license. For remote Telnet boards, guide updates, online ANSI artpacks and IRC, an Internet connection is needed.
Serial or FujiNet: For a CoCo 3, use a Deluxe RS-232 Pak, NetMate, a suitable null-modem connection and a USB serial adapter on Windows (19200 baud is one example). FujiNet can connect through RMB's network listener instead. Door Game Mode remains experimental and compatibility depends on the program.
Official downloads / source / release notes
RetroModem Bridge v3.6
Version 3.6 is available as a free, self-contained Windows x64 ZIP on the official website. Tequestafarian hosts project notes and screenshots only; downloads and release details belong on RetroModemBridge.com.
Support the projects
Buy me a coffee
RetroModem Bridge is free. If you enjoy these projects and want to support the work, there's an optional PayPal tip jar.