@PaulaMaddox no, it's all CP/M and Zilog Z80 (8-bit) based. No Linux host or custom code involved.

It simply utilizes a WiFi modem with Zimodem firmware to connect to the outside world. 📡 This is where you telnet into.

The WiFi modem is connected to the SIO/2 serial I/O port of the RC2014 at a whooping 9600 bps and BYE.COM on CP/M then handles the incoming serial connection ... the modem also takes care of the "single-user" handling by only allowing one telnet connection at a time. So if someone is already connected, you will only get a "BBS busy" message and be disconnected.

You can read about how it's done in detail on the BBS itself, in the text files section ("A brief history of RC-BOX BBS"). And I blogged about it here:

https://ufud.org/posts/2024-02-05-rc-box-bbs/