cwcp(1) curses-based Morse tutor program


cwcp [-s --system=SYSTEM] [-d --device=DEVICE] [-w --wpm=WPM] [-t --tone=HZ] [-v --volume=PERCENT] [-g --gap=GAP] [-k --weighting=WEIGHT] [-T --time=TIME] [-f, --infile=FILE] [-F, --outifile=FILE] [-h --help] [-V --version]

cwcp installed on GNU/Linux systems understands both short form and long form command line options. cwcp installed on other operating systems may understand only the short form options.

There are no mandatory options.

Options may be predefined in the environment variable CWCP_OPTIONS. If defined, these options are used first; command line options take precedence.


cwcp is a curses-based interactive Morse code tutor program. It allows menu selection from a number of sending modes, and also permits character sounding options, such as the tone pitch, and sending speed, to be varied from the keyboard using a full-screen user interface.


cwcp understands the following command line options. The long form options may not be available in non-LINUX versions.
-s, --system=SYSTEM
Specifies the way that cwcp generates tones. Valid values are: null for no tones, just timings, console for tones through the console speaker, alsa for tones generated through the system sound card using ALSA sound system, oss for tones generated through system sound card using OSS sound system, pulseaudio for tones generated through system sound card using PulseAudio sound system, soundcard for tones generated through the system sound card, but without explicit selection of sound system. These values can be shortened to 'n', 'c', 'a', 'o', 'p', or 's', respectively. The default value is 'pulseaudio'.
-d, --device=DEVICE
Specifies the device file to open for generating a sound. cwcp will use default device if none is specified. The default devices are: /dev/console for sound produced through console, default for ALSA sound system, /dev/audio for OSS sound system, a default device for PulseAudio sound system. See also NOTES ON USING A SOUND CARD below.
-w, --wpm=WPM
Sets the initial sending speed in words per minute. The value must be between 4 and 60. The default value is 12 WPM.
-t, --tone=HZ
Sets the initial sounder pitch in Hz. This value must be between 0 and 4,000. A value of 0 selects silent operation, and can be used for timing checks or other testing. The default value is 800Hz,
-v, --volume=PERCENT
Sets the initial sending volume, as a percentage of full scale volume. The value must be between 0 and 100. The default value is 70 %. Sound volumes work fully for sound card tones, but cwcp cannot control the volume of tones from the console speaker. In this case, a volume of zero is silent, and all other volume values are simply sounded.
-g, --gap=GAP
Sets the initial extra gap, in dot lengths, between characters (the 'Farnsworth' delay). It must be between 0 and 60. The default is 0.
-k, --weighting=WEIGHT
Sets the initial weighting, as a percentage of dot lengths. It must be between 20 and 80. The default is 50.
-T, --time=TIME
Sets the initial practice time, in minutes. cwcp stops after generating random Morse code for this period. The value must be between 1 and 99. The default is 15 minutes.
-f, --infile=FILE
Specifies a text file that cwcp can read to configure its practice text. See CREATING CONFIGURATION FILES below.
-F, --outfile=FILE
Specifies a text file to which cwcp should write its current practice text.
-h, --help
Prints short help message.
-V, --version
Prints information about program's version, authors and license.


cwcp is a curses-based program that takes over the complete operation of the terminal on which it is run. If colours are available on the terminal, it will produce a colour interface.

The cwcp screen is divided into several distinct areas:

The Menu Selection window
The Menu Selection window shows the main modes that cwcp offers. Use the F10 and F11 or KEY_DOWN and KEY_UP keys to select the mode. F9 or Return start sending, and F9 again or Esc stop sending. Changing mode also stops sending.
The Morse Code Display window
This window displays each Morse code character after it has been sent.
The Speed Control window
The Speed window shows the current Morse code sending speed in words per minute. Pressing the F2 or KEY_RIGHT keys increases the speed; pressing the F1 or KEY_LEFT keys decreases the speed.
The Tone Control window
This window shows the current Morse code tone pitch. Use the F4 or KEY_HOME key to increase the pitch, and the F3 or KEY_END key to decrease it. Values change in steps of 20Hz.
The Volume Control window
This window shows the current Morse code volume. Use the F6 key to increase the volume, and the F5 key to decrease it. Values change in steps of 1%. Note that cwcp cannot control the volume of the console speaker, so the volume control only works effectively for tones generated on the sound card.
The Gap Control window
This window shows the current additional 'Farnsworth' gaps to be appended after each Morse code character is sounded. Use F8 to increase the gap, and F7 to decrease it.
The Time Control window
This window shows the selected practice time. After generating Morse code in a particular mode for this amount of time, cwcp stops automatically. Use KEY_NPAGE to increase the time, and KEY_PPAGE to decrease it. During sending, the value in this window counts down to one, and after final minute of sending has elapsed, cwcp stops sending. The timer operates like a microwave or kitchen timer; it counts down on its own, but the time remaining can also be altered manually while the timer operates.

The following keys vary the screen colours:

{ key
Changes the foreground colour of the window boxes.
} key
Changes the background colour of the window boxes.
[ key
Changes the foreground colour of the window contents.
] key
Changes the background colour of the window contents.

Eight screen colours are available for each: black, red, green, yellow, blue, magenta, cyan, and white. Use a key to cycle round these colours for the particular part of the display controlled by that key. On a change of colours, the complete screen is repainted.

Use Ctrl-L to repaint the complete screen, in case of screen corruption. Use Ctrl-V to clear the Morse Code Display Window. This command is available only when cwcp is not sending.

To leave cwcp, press F12 or Ctrl-C, or select Exit on the mode menu.

All of the above command keys may be used while random characters are being sent, and when keyboard input is being sent.

If function keys are not available on the terminal, Ctrl-<key> combinations can be used. On the top row of letter keys on the keyboard, the keys Ctrl-Q to Ctrl-I may be used as alternatives for F1 to F8, and on the second row of letter keys, Ctrl-A to Ctrl-F as alternatives for F9 to F12. For KEY_PPAGE and KEY_NPAGE, use Ctrl-O and Ctrl-P.


cwcp sends random characters in groups of five, with a space between each group. After a period of sending, set in the Time Control window, cwcp stops automatically. It can also be stopped manually, before this time period expires.

When sending random words, cwcp sends the complete word, followed by a space. Because short words are easier to copy without writing, cwcp's default dictionary contains only three, four, and five-letter words in its random words list.

cwcp chooses at random from a list of around 3000 words in its default dictionary. You can change this text using a configuration file, read at startup. See CREATING CONFIGURATION FILES below.


By default, cw tries to open default PulseAudio. If PulseAudio server is not accessible, cw tries to open OSS device "/dev/audio" to access the system sound card. This is generally the correct device to use, but for systems with special requirements, or those with multiple sound cards, the option -d or --device, combined with -s or --system can be used to specify the device and audio system for sound card access. If the sound card device cannot be set up, cwcp prints the error message
cannot set up soundcard sound

and exits.

Sound card devices, when opened through OSS sound system, are usually single-access devices, so that when one process has opened the device, other processes are prevented from using it. In such cases cwcp will of course conflict with any other programs that expect exclusive use of the system sound card (for example, MP3 players). If cwcp finds that the sound card is already busy, it prints the error message

open /dev/audio: Device or resource busy

and exits.

The sound card device is not used if cwcp is only sending tones on the console speaker.


cwcp first tries to access sound card using PulseAudio sound system, using default device name, unless user specifies other audio device with option -d or --device.

cwcp then tries to access sound card using OSS audio system and default OSS audio device name ('/dev/audio'), unless user specifies other audio device with option -d or --device.

If opening soundcard through OSS fails, cwcp tries to access the sound card using ALSA audio system, and default ALSA audio device name ('default'), unless user specifies other audio device with option -d or --device.

If opening soundcard through ALSA also fails, cwcp tries to access system console buzzer using default buzzer device '/dev/console', unless user specifies other audio device with option -d or --device.

It is very common that in order to access the console buzzer device user has to have root privileges. For that reason trying to open console buzzer almost always fails. This is not a program's bug, this is a result of operating system's restrictions. Making cwcp an suid binary bypasses this restriction. The program does not fork() or exec(), so making it suid should be relatively safe. Note however that this practice is discouraged for security reasons.

As stated, user can tell cwcp which device to use, using -d or --device option. Which device files are suitable will depend on which operating system is running, which system user ID runs cwcp, and which user groups user belongs to.


cwcp contains a default set of modes and practice text that should be enough to begin with. It can however read in a file at startup that reconfigures these to provide different character groupings, word sets, and other practice data.

To read a configuration file, use the -f or --infile command line options. The file should introduce each cwcp mode with a section header in '[' ... ']' characters, followed by the practice text for that mode, with elements separated by whitespace. Lines starting with a semicolon or hash are treated as comments. For example

; Simple example mode
[ A to Z ]

cwcp will generate five character groups for modes whose elements are all single characters, and treat other modes as having elements that are complete words. As a starting point for customized modes, cwcp will write its default configuration to a file if given the undocumented -# option, for example "cwcp -# /tmp/cwcp.ini".


cwcp owes its existence to the DOS Morse code tutor CP222C.EXE, by VU2ZAP. CP222C.EXE seemed to offer the right range of facilities for learning Morse code in a simple, easy-to-use, and compact package. cwcp is very much modeled on that DOS program, and should prove useful both for learning the code, and for experienced CW users who want, or need, to improve their receiving speed.

Curses may impose a delay when recognizing the Esc key alone, as this character is often the first of a sequence generated by a function key. cwcp responds instantly to F9.

The characters echoed in the Morse Code Display window may be ASCII representations of Morse procedural signals; see the cw(7,LOCAL) man page for details.


Here are a few hints and tips that may help with the process of learning Morse code.

Firstly, do NOT think of the elements as dots and dashes. Instead, think of them as dits and dahs (so 'A' is di-dah). If you think of them in this way, the process of translating sound into characters will be learned much more easily.

Do not learn the characters from a table. Learn them by watching the groups appear on the screen, and listening to the sounds produced as each is sent. In the very initial stages, it may be beneficial if you can find a person to take you through the first stages of recognizing characters.

Do not waste your time learning Morse code at 5 WPM. Set the speed to 12 or 15 WPM, but use extra spacing (the Gap window) to reduce the effective speed to much lower - around four or five WPM effective speed. This way, you will learn the rhythm of the characters as they are sent, but still have plenty of time between characters. As you practice, decrease the gap to zero.

Learn in stages. Start by learning the EISH5 group, then progress down through the menu as each group is mastered. The groups contain characters which are in some way related, either by sound, or by type of character.

Once you have completed all the groups EISH5 to 22'$(+:_ (or 23789 if you do not want to learn procedural signals yet), use the full character set options, and the words and CW words options, to sharpen your skill. If you have difficulties with particular characters, return to that group and practice again with a smaller character set.

Resist the temptation to try to learn or improve your speed by copying off-air. You will not know what speed you are working at, and much hand-sent Morse is not perfectly formed. What you can gain off-air though is a general 'resilience', a tolerance for Morse code where the timing of individual elements, or spacing between characters and words, is not 100% accurate.

If working to attain a particular speed for a test, always set the speed slightly higher. For example, if aiming for 12 WPM, set the tutor speed to 14 or 15 WPM. This way, when you drop back to 12 WPM you will feel much more relaxed about copying. Be aware that cwcp is not necessarily going to send at exactly the speed you set, due to limitations in what can be done with UNIX timers. It often sends at a slower speed than you set, so be very careful with this if you have a target speed that you need to reach.

Use the program to make cassette tapes that you can take with you in a walkman or in the car, for long journeys. You do not have to write down everything you hear to practice Morse code. Simply listening to the shapes of characters over a period will help to train your brain into effortless recognition. In fact, slavishly writing everything down becomes a barrier at speeds of 15-20 WPM and above, so if you can begin to copy without writing each character down, you will find progress much easier above these speeds. But do not over-use these tapes, otherwise you will quickly memorize them. Re-record them with new contents at very regular intervals.

Try to spend at least 15-30 minutes each day practicing. Much less than this will make progress glacially slow. But significantly more than an hour or so may just result in you becoming tired, but not improving. Recognize when it is time to stop for the day.

Do not worry if you reach a speed 'plateau'. This is common, and you will soon pass it with a little perseverance.

At higher speeds, CW operators tend to recognize the 'shape' of whole words, rather than the individual characters within the words. The CW words menu option can be used to help to practice and develop this skill.


The calibration option is a bit ropy. It simply sends PARIS repeatedly, and relies on you to time the sending and then work out if any adjustment to the speed is really necessary. Automatic calibration by making measurements over a given period would be a lot better.

Generating random CW QSOs would be fun to do.

A facility to allow a user to key Morse into the system, and to have it send code, and measure the accuracy of keying, would be nice.