OS/2 and virtual COM ports.

With TCP/IP working under OS/2 I went looking for the next thing that I’ve always wanted, and that is a good modem emulator.  Funny enough SIO the COM driver replacement for OS/2 actually includes this functionality.

And has for years… I just never knew it.

I know in the NT centric would we live in today, it’s all moot, but I thought it was really interesting for those of us that still hinge on modems… And freaky hardware, since OS/2 can let some things talk directly to the hardware without OS/2 drivers (IOPL=YES).

So for the sake of it, I downloaded version 1.60 of SIO, went through the install, then added a virtual modem as described to my config.sys .. And I placed a test ‘call’ with OS/2’s terminal program, and I was talking to my MUD!

So I thought I’d try something crazier, like load up a BBS, then configure it for four modems!


And it worked!

Sure there are some slightly easier to configure ways to achieve this (DOSBox includes modem support), and I suppose the better thing to do would be to give virtual modems to Qemu.  Then OS’s with no TCP/IP can benefit from this.

This entry was posted in modems, OS/2, OS/2 2.0, qemu, virtual networking by neozeed. Bookmark the permalink.

About neozeed

What is there to tell? I've loved UNIX like things since I was first exposed to QNX in highschool (we had the Unisys ICONS!), and spent the better time of my teenage years trying to get my own UNIX... I should have bought Coherent in retrospect.. Anyways latched onto Linux in 1992, and then got some old BSD admin books and have been hooked on the VAX BSD & other big/ancient things since...!

2 thoughts on “OS/2 and virtual COM ports.

  1. Sure there are some slightly easier to configure ways to achieve this (DOSBox includes modem support), and I suppose the better thing to do would be to give virtual modems to Qemu. Then OS’s with no TCP/IP can benefit from this.

    Actually, a while back I wrote a Hayes modem emulator in Perl, and I put the source code on GitHub a few weeks ago. It works with QEMU and other emulators, and you can use it to “call” telnet servers or local processes (SLiRP can be used to provide Internet access, if your guest supports PPP and TCP/IP). You can even call between virtual machines.

    There’s not very much documentation, and the support for Windows hosts is somewhat poor (although I have tested it in Cygwin, and added partial support for Win32 Named Pipes). Also, it doesn’t (yet) support translating incoming telnet connections into incoming calls, which looks like what you’re doing there, but it works nicely with MSIE5.01 to bring the Internet to Windows 3.1.

    P.S. One notable limitation is that emulators don’t support the extra serial pins (e.g. DTR) used to indicate the carrier status. Some systems, WfW/NT3 RAS being the only one I’ve found so far, insist on this and I wouldn’t be surprised to discover that OS/2 is one of them.

    • Wow that’s pretty cool sounding! I may have to try to fight it with Xenix to see how far I can get it to at least talk to things. Even an outbound only connection for UUCP is enough to pickup & drop off files… So it can’t be Xenix to Xenix but that’s ok too. It’d be cool to get it hooked up to UUHecnet.

      Thanks again for the great info!

Leave a Reply

Your email address will not be published.

Notify me of followup comments via e-mail. You can also subscribe without commenting.