Connecting openMSX to the Internet using the RS232 port

RS232 port on the MSX was the gateway to connectivity in its heyday, facilitating communication with terminals, modems, and more. It symbolized the era of BBSes, where the distinct modem screech heralded entry into a world of digital communities and file exchanges. The MSX, with its RS232 interface, was a trusty companion on these virtual journeys, bridging the gap between our world and the boundless realm of cyberspace. It's a nostalgic reminder of simpler times, where every connection held the promise of adventure and discovery. Let's fast forward to the future! With OpenMSX recently gaining RS232 support through a virtual port. This development opens up exciting possibilities, enabling enthusiasts to explore new ways of interaction and communication.

Let's not reminisce too much and get to the point, how do I connect openMSX to a telnet\bbs session?

Special Thanks

A big thanks to Pablo Roldán (Durandal) who laid the groundwork for the RS232/tcpser network support.

Download tcpser

First let's make sure we have a program called 'tcpser'

The windows version comes precompiled, the linux and mac versions can be easily compiled with the 'make' command on the command line

Setup tcpser

We are now ready to start tcpser with the following command line: 

tcpser -p 6502 -v25232 -l4 -s 9600 -n555=sotanomsxbbs.org:23
Let me break down this command line in detail:
  • -p 6502 is the port we can use to make a connection with openMSX
  • -v 25232 is the port tcpser will communicate with the outside world
  • -l4 indicates the log level we want to see while connecting and using tcpser
  • -s 9600 sets the max reported speed to 9600bps (no impact it is only cosmetic)
  • -n555 =sotanomsxbbs.org:23 - this is a phone book entry to be used in an example below
    •

    Setup openMSX

    Currently this only works on the nightly builds located here

    The next step is to instruct openMSX to connect to tcpser and to use this as a virtual rs232 port:

  • Make sure you use an MSX2/Turbo-R for this with basic support. Do not use c-bios as it lacks basic support.
  • open the command line in openMSX
  • type 'set pause on' - this will pause openMSX and gives us time to setup rs232 communication
  • type 'reset' - this will reset the openMSX instance
  • type 'extb Sony_HBI-232' this will insert the rs232 extension into the running openMSX instance
  • type 'set rs232-net-address 127.0.0.1:25232' this will connect openMSX to tcpser on the port we specified in the tcpser setup instructions
  • type 'set rs232-net-ip232 on' - this will setup and activate the rs232 port
  • type 'plug msx-rs232 rs232-net' - this command will allow/plug the rs232 port into the openMSX instance
  • type 'set pause off' - we now boot into the openMSX instance

    • Communicating with the outside world

    This is where the fun starts:

    Congratulations! if you have done everything correctly you are now connected to the sotanomsxbbs.org bbs.

    Further resources

    MSX rs232 documentaton

    Color Terminal emulators BBS-es