Null-modem emulator Icon

Null-modem emulator

The virtual serial port driver for Windows.

4.6 Stars (84)
1,502 Downloads (This Week)
Last Update:
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The Null-modem emulator (com0com) is a kernel-mode virtual serial port driver for Windows. You can create an unlimited number of virtual COM port pairs and use any pair to connect one COM port based application to another. The HUB for communications (hub4com) allows to receive data and signals from one COM or TCP port, modify and send it to a number of other COM or TCP ports and vice versa.

Null-modem emulator Web Site


  • com0com: baud rate emulation
  • com0com: pinouts customization
  • com0com: noised line emulation
  • com0com: paired port settings monitoring (baud rate, data bits, stop bits, parity)
  • com0com: hiding 'unavailable' ports from user
  • hup4com: spliting data from one serial device into several virtual serial ports
  • hup4com: redirecting serial to TCP/IP and TCP/IP to serial
  • hup4com: RFC2217 - Telnet Com Port Control Option (client and server)


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User Ratings

ease 1 of 5 2 of 5 3 of 5 4 of 5 5 of 5 3 / 5
features 1 of 5 2 of 5 3 of 5 4 of 5 5 of 5 4 / 5
design 1 of 5 2 of 5 3 of 5 4 of 5 5 of 5 3 / 5
support 1 of 5 2 of 5 3 of 5 4 of 5 5 of 5 3 / 5
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User Reviews

  • 1 of 5 2 of 5 3 of 5 4 of 5 5 of 5


    Posted 03/04/2017
  • 1 of 5 2 of 5 3 of 5 4 of 5 5 of 5

    For those having trouble gettings the driver to work, you should make sure to install the signed version. Works great. Also, the COM ports do not show up in the Ports (COM & LPT) in device manager. They show up in a new device category for com0com and you can't set the port settings as you can on regular ports. Whether that is good or bad I leave to your own judgement.

    Posted 11/18/2016
  • 1 of 5 2 of 5 3 of 5 4 of 5 5 of 5

    I downloaded several programs for emulation virtual null modems, also com0com. But the best for me is Null Modem Emulator by Eltima - this software is fully baked.

    Posted 10/03/2016
  • 1 of 5 2 of 5 3 of 5 4 of 5 5 of 5

    It does not work!!! In Device Manager it does not show up in Ports(COM& LPT) and I have tried it on a few computers now

    Posted 06/20/2015
  • 1 of 5 2 of 5 3 of 5 4 of 5 5 of 5

    For those of you having trouble with driver signing in Windows 8/8.1, do a google search for: windows 8 disable driver signature enforcement It should be the first link listed at

    Posted 02/24/2015
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Additional Project Details

Intended Audience

Advanced End Users, Developers, Testers

Programming Language

C, C++



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