Are there standard ways to connect a hand key (straight or paddle) to a contemporary computing device (PC laptop with no parallel port, Mac, Android, iOS device, etc.) for developing or improving ones Morse code sending skills?

If so, can one use this setup to do hand-key QSOs, either using a remote transmitter if appropriately licensed, or directly over the internet?

  • $\begingroup$ Google AMECO code practice oscillator or find one on EBay. I used one way back almost 60 years ago. Works well -- two tube oscillator circuit. $\endgroup$
    – K7PEH
    Mar 17, 2017 at 5:24
  • 1
    $\begingroup$ Not quite an answer, but if you want to improve your sending skills, try out this fist checker: (Precision CW Fist Checker) qsl.net/dj7hs/download.htm $\endgroup$ May 31, 2017 at 14:50

6 Answers 6


A really easy way to do this is to take an old USB mouse (or even a new cheap one) and solder the key across the left mouse button. You can then use key directly as mouse button input on most computers and Android phones (with an OTG cable) and use with Morse software or websites expecting mouse input e.g. :-



For hours of fun and practice.

Update: Your question inspired me to do a little better so I created this blog post in the hope that it's useful http://whaley.org.uk/andrew/blog/2017/04/28/morse-code-cw-via-usb/

It covers 2 methods; the quick mouse option but also something a lot more versatile which isn't that much more effort.

  • $\begingroup$ Sorry for necroing. I came across this in the SE newsletter. Your website throws an error Error establishing a database connection $\endgroup$
    – rsn
    Mar 20 at 16:17

How you do this will be dictated by the software you select. However, most software I have seen uses some of the control lines on an RS-232 serial port. Calling it a "standard" might be a stretch, but there seems to be a convention:

CW key connection

More at the source, F8EHO.net.

It's also possible to use some of the other control lines to drive an opto-isolator or relay which in turn connects to the key jack on your radio. Thus, your computer looks, to the transmitter, as an external keyer. Again, no real standards, besides those imposed by the software you select.

No doubt, it is possible to send Morse code over the internet. Any application that can send audio over the internet could do it, for example, Skype. You'd simply need to set the input of your audio-over-internet application to be the output of your morse-code-keyer application, instead of a microphone. Of course, there is no standard way to do this either, just as there is no standard communication program, or standard keying software, or standard operating system.


Well, I can't answer as to “standard” as I'm just learning myself, but I can think of a couple of ways to do this without getting into completely custom interface hardware and drivers, or needing an interface with directly readable signal lines like a serial port or parallel port which is less common these days:

  • Connect the key to a code practice oscillator that has a line-level audio output, then connect the audio to your computer's line-in.

    (I can't find a good existing explanation to link here! A code practice oscillator is just a device with key input, audio output (usually with a built-in speaker), and an internal oscillator so that it can produce an audio tone that is switched on and off by the key input. I don't know how commonly available a line output is.)

    This would allow you to practice using “decode Morse from audio” apps, which I understand are available on smartphone platforms, for example. It could be used to transmit using a remotely controlled transmitter; if in SSB mode (and the CPO's output is a good sine wave, which is worth checking), the result is equivalent to CW (though probably less clean), but in FM or AM modes it is modulated continuous wave.

    For practice rather than transmission purposes, it would be adequate to use a CPO without line output, and a regular microphone attached to your computer that picks the sound up.

  • Turn the key into a keyboard keyswitch. This could be done by connecting it to the appropriate points on the switch matrix of a regular keyboard; you might also be able to find a specific-purpose device (or plans for one) for connecting arbitrary switches as keyboards, for the arcade-cabinet or assistive-device (for disabilities) markets, but I haven't looked hard myself.

    This requires software which will interpret a keyboard key as a Morse key. I don't know anything about the existence of such; I just mention this option because from a computer-peripheral-interfacing perspective it's the most fitting.


Many CW keyers (such as the WinKeyer) will convert what you key back to text. I used flwkey to see what I was (attempting) to send as code practice.


CWCOM by MRX software, http://www.mrx.com.au/d_cwcom.htm can be used with a straight or iambic key..

If you do not have a 9 pin serial port ( as most laptops do not ).. you will need to buy a USB to Serial Adapter cable...( Like this ... https://h10003.www1.hp.com/digmedialib/prodimg/lowres/c00618023.jpg ) can be found on ebay . and also a DB9 plug or socket ( depending on the one on the adapter) to connect your key to it. It is pretty straight forward. but you might need to set the COMPORT number in devices. There is a good "help" page provided . You do not need a ham licence to use it. It works in Windows up to WIN 7 32 bit... 64 bit windows is tricky. It can be made to work on Linux OS... I did get it to work on Linux Mint 16


UPDATE the site www.mrx.com.au is not working... the owner no longer services it....

**to download CWCOM please visit my blogsite


where there are pages of info and help,. including how to get cwcom ( written for windows ) working on LINUX and MAC machines.

Also detailed instructions on how to connect external morse key to your computer.

  • $\begingroup$ Just like that other site is not working, yours may not work in the future, either. It is called link-rot. Please show us the instructions. $\endgroup$
    – SDsolar
    Aug 3, 2017 at 5:09
  • $\begingroup$ SDsolar morsepower.blogspot.co.uk/p/blog-page.html is working, and has always worked... $\endgroup$
    – Gerry
    Aug 5, 2017 at 16:32
  • $\begingroup$ November 2020... and the blogsite is still operational.. and has been updated to include touch screen working, and also how to install CWCOM on LINUX AND MAC machines. morsepower.blogspot.com Go through the menu pages for full instructions, with pics, in most cases ! ! enjoy CWCOM is alive and kicking ..every day 73 dit dit $\endgroup$
    – user18153
    Nov 26, 2020 at 15:42

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