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D-Modem

An open V.92 softmodem, and the app, boards and servers built around it.

Dial a BBS, a fax machine or an ISP from a SIP call, a phone, or a real phone line, with no modem hardware. Or run the other end: answer modem callers on a PBX and give them a login, a menu and a bulletin board.

The suite

  • D-Modem

    The softmodem: V.92 down to Bell 103, class 1, 2 and 2.0 fax, V.42 and V.44. dmodemd puts it on a SIP line; modules put it in Asterisk, FreeSWITCH and FreePBX. Linux, Windows, macOS and Haiku.

  • app

    The D-Modem app for Android and iOS: a modem whose phone line is a SIP call, with a terminal, a dialling directory, fax and dial-up internet.

  • hardware

    pico-serial: open RP2040 boards that connect D-Modem to vintage serial ports and to real telephone lines.

  • menu

    modemmenu: the login and menu dial-up callers see first, with PPP, a shell, the BBS or any program behind it.

  • bbs

    A bulletin board in Go for telnet, SSH, TN3270 and modem callers, with message areas, FidoNet, doors and file transfers.

  • go3270

    A Go library for TN3270 servers, the suite's fork of racingmars/go3270. bbs draws its 3270 screens with it.

  • gui

    Native desktop apps for D-Modem, in the works: the modem, its terminal and fax in a window on Windows, macOS and Linux.

  • brand

    The mark, the Rainbow Book colours, type, the naming guide, and the theme every D-Modem site shares.

Start here

  • Dial out from a computer: build D-Modem and run dmodemd with a SIP account, then dial from any terminal program.
  • Dial out from a phone: install the D-Modem app.
  • Use a real phone line or serial port: see the pico-serial boards.
  • Answer callers: put D-Modem in Asterisk, then modemmenu and the bbs behind it.

How the pieces fit together