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Call telnet bulletin boards from a Commodore 64 with a Wi-Fi modem

by The RetroMake desk 26 October 2026

A user-port StrikeLink or an RS-232 WiModem232 Pro, the CCGMS terminal program, the AT commands each modem's own manual gives for joining Wi-Fi, how each one dials a host and port, and three Commodore boards to try.

verified 26 Oct 2026. 1388 words.

Difficultybeginner
TimeAn afternoon
Cost$50 to $104 (USD)
SkillsLoading and running a program on a C64, Typing commands into a terminal program

Parts

Tools

  • A Commodore 64 with a working power supply
  • A way to load a PRG file on the C64, such as an SD2IEC or a disk drive and a disk written on a PC
  • CCGMS Future 0.2, free, from its GitHub releases page
  • The name and password of your Wi-Fi network

What you are building

A Commodore 64 that calls bulletin boards over the internet the way it once called them over a phone line. A Wi-Fi modem pretends to be a Hayes-compatible modem: the C64's terminal program sends it the familiar AT commands, and instead of dialling a phone number it opens a telnet connection to a host name and port. Dozens of Commodore boards still answer that way, several of them running on real Commodore hardware.

RetroMake has not run this setup. Every command and setting below comes from the StrikeLink and WiModem232 Pro manuals and the CCGMS Future documentation, which are listed in the sources; where those documents are silent, this guide says so rather than guessing.

How it works

The C64 has no RS-232 chip. Its user port exposes a TTL-level serial port that the KERNAL drives in software, and Michael Steil's history of the port notes that while the driver nominally supports 2400 baud, only speeds up to 1200 are stable because the video chip steals cycles from the processor. In 1997 Daniel Dallmann worked out how to use the shift registers in the two CIA chips to reach 9600 baud with slightly different wiring. That wiring, UP9600, "has become the de-facto standard for all modern accessories, like C64 WiFi modems."

Two kinds of modem follow from that. A user-port modem plugs straight into the port and works at TTL levels. An RS-232 modem has a standard serial connector and needs an interface between it and the user port that converts the levels, in the tradition of Commodore's VIC-1011.

Which modem

The StrikeLink, designed by Alwyz, is the simple route. It plugs into the user port, comes "pre-configured for 9600 baud use", and is meant for the CCGMS terminal program. Retro4all's Tindie listing priced it at $49.99 with five left on 26 October 2026, and Retro Lemon listed it at GBP 45.00 including VAT.

The WiModem232 Pro from CBM Stuff costs $59.95 and was in stock the same day. It is a general-purpose RS-232 modem with a colour screen, speeds from 75 to 230400 baud and a female DB25 connector, and it needs its own 5 V supply. The Commodore 64 is not on its list of tested computers, and it needs an RS-232 interface to use it. Every such interface RetroMake found was unavailable on 26 October 2026: the GGLabs GLINK-LT ($39.00) because its seller was "taking a break", the 8bit_bruno adapter ($30.00) because it has been "Sold out since Jan 05, 2026", and Simulant's UK adaptor (GBP 23.00) because it was out of stock. RETRO Innovations says its Link232 cartridge is not currently available either. The GLINK-LT has a male DB9 connector, and CBM Stuff's female DB9 to male DB25 adapter is made to plug into the WiModem232.

For a first setup, the StrikeLink has fewer parts.

The StrikeLink instructions were written for CCGMS 2017 v4. CCGMS Future, Michael Steil's 2022 continuation of the same program, keeps the settings menu on F7 and the terminal-mode switch on F8, and its documentation mentions the StrikeLink by name in its dialer settings.

  1. With the C64 switched off, plug the StrikeLink into the user port with its logo side up.
  2. Switch on and load CCGMS.
  3. Press F7 for the settings menu. Set the modem type to UP9600 and the baud rate to 9600.
  4. Save the phone book and configuration, then press Return to enter terminal mode and press Return again. The manual says the StrikeLink should answer with a greeting.
  5. Press F8 until the terminal is in ASCII mode. The manual says this helps the modem read your network name and password correctly.
  6. Type at$ssid= followed by your network name, and press Return.
  7. Type at$pass= followed by your Wi-Fi password, and press Return.
  8. Type atc1 to connect to the network (atc0 disconnects).
  9. Type at&w to store the settings in the modem permanently.
  10. Press F8 until the terminal is back in PETSCII mode.

The StrikeLink manual gives no typed dial command. It sends you to the CCGMS auto-dialer instead, and says that at? gives a list of the modem's AT commands. Pressing Return in terminal mode and getting the greeting is the first sign that the C64 and the modem are talking.

Steps with a WiModem232 Pro

  1. Connect the RS-232 interface to the user port with the C64 off, and the modem to the interface, using a DB9 to DB25 adapter if the connectors need one.
  2. Power the modem from a 5 V USB supply and switch on the C64.
  3. Load CCGMS. In the F7 menu choose the modem type that matches the interface: User Port allows 300 to 2400 baud, and UP9600 allows up to 9600 but needs an interface wired for it. Set 300 baud, the modem's default, and choose ASCII mode with F8.
  4. In terminal mode type ATI. The manual says the modem replies with its firmware version, baud rate and network status.
  5. Join the network. Press the WPS button on your router and type AT*WPS, or type AT*N to list nearby networks and then AT*SSID followed directly by the network name, a comma and the password, with no space after SSID. The manual says a name typed this way cannot contain spaces. WPS, the AT*WIFI setup portal for a phone, and AT*NS followed by the network's number from the AT*N list, a comma and the password, all avoid typing the name.
  6. When the modem reports "Connected to" your network, type AT*B2400 (or AT*B9600 on a UP9600 interface), then change the CCGMS baud rate to match.
  7. Type AT&W to store the settings.

To call a board directly, the manual's form is ATDT followed immediately by the host name, a colon and the port, with no space after ATDT.

Calling a board

In CCGMS, open the auto-dialer from the F7 menu and edit an entry. Each one has a name, an address (a DNS name or IP address), a port, and optionally your user ID and password. Leave the Firmware setting on Standard: the CCGMS documentation says StrikeLink and WiModem firmware do not accept quotes around the address, while Zimodem firmware requires them.

These three Commodore boards come from the Telnet BBS Guide and the Oasis BBS listing, with addresses exactly as listed. RetroMake has not connected to them.

BoardSoftwareAddress
Citadel 64 BBSColor 64 v8citadel64.thejlab.com:6400
Commodore ImageImage BBScib.dyndns.org:6400
RapidFire BBSC-Baserapidfire.hopto.org:64128

Citadel 64's listing describes a "Real Commodore 64 system running Color 64 v8 BBS" that supports PETSCII and ANSI. Commodore Image calls itself "the original support BBS for Image BBS for the Commodore 64 and 128". RapidFire runs C*Base, which both listings spell C-Base. For Citadel 64, the phone book entry's address is citadel64.thejlab.com and its port 6400. Once connected, Ctrl+F5 and Ctrl+F7 send the stored user ID and password.

Testing

On a WiModem232 Pro, ATDTGOOGLE.COM:80 is the manual's own test: "CONNECT" means the internet path works. Press + three times within a second, wait for "OK", then type ATH to hang up. After that, call one of the boards above at your chosen speed and check that its menus draw cleanly in PETSCII.

Troubleshooting

  • The StrikeLink will not join the network: type atc1 again, as its manual suggests, or press its reset button.
  • Garbled text on the StrikeLink: the manual says hardware flow control must be on with the UP9600 setting (at&k1), and off (at&k0) only if you switch CCGMS to the plain user-port driver.
  • After an accidental factory reset (at&f), the manual says to connect at 300 baud and type at&p0, at&k1 and at$sb=9600.
  • The WiModem232 Pro cannot find the router: AT*N shows each network's signal strength. The manual calls readings "higher than -85dBm" marginal and suggests keeping metal, such as hard drives, away from the modem.
  • File transfers fail on UP9600: the CCGMS Future README lists a known bug in which XMODEM, and possibly Punter, may be broken for UP9600 devices.
  • On a Commodore 128, the CCGMS documentation says its UP9600 driver does not work.