This is the homepage of jpnevulator. What once started as a Jackpot Navigator emulator (hence the strange name) is now a nice serial sniffer and you can use it to send data on a serial line too. It's sort of like a very simple terminal emulator, like picocom. But jpnevulator uses hexadecimal byte values to display and send along the line. Very handy indeed if you are working a lot with serial protocols.

jpnevulator is released as Free Software under the GPL license. See the file COPYING in the source tarball for more information.

If you have a question, please first read the FAQ. It's kind of a pathetic FAQ file for now, but I bet your question is in it!


These are the (max. 10) most recent news items about the project:

21/01/2015-Link of the day
Rolf Freitag first came up with the idea to use threads to solve the "Order of bytes broke when reading several tty devices at once" bug and next did an implementation to prove his point: If you are hunted by this bug and need a solution, maybe you can try his software as I do not see myself perform such a huge change of the software anytime soon.

Select a year and press 'See News' to see some more (old) news:

Example of the output

Below is an example of the output one can see when reading from two serial devices at the same time:

$ jpnevulator --ascii --timing-print --tty /dev/ttyS0:SB9600d --tty "/dev/ttyUSB0:Motorola MTM800" --read
2006-05-30 13:23:49.461075: SB9600d
00 00 05 3B 0D 00 00 05                         ...;....
2006-05-30 13:23:49.461113: Motorola MTM800
00 05 3B 0D 00 00 05 3B 0D                      ..;....;.
2006-05-30 13:23:49.473074: SB9600d
3B 0D 00 00 05 3B 0D                            ;....;.
2006-05-30 13:23:49.473105: Motorola MTM800
00 12 05 06 39 00 12 05 06 39 1F 00 22 80 00 0E ....9....9.."...



The current release of jpnevulator is version 2.1.3, which was released on August 5th, 2014. Download this compressed tarball(33.2K) and see the README and INSTALL file for more information on how to compile the program.

Older versions can be found here.

Debian GNU/Linux

jpnevulator is an official part of the Debian operating system. You can find information about it at

All the ever released packages can be also be found here.


jpnevulator is written and maintained by Freddy Spierenburg. Feel free to send questions, bugfixes and the like to

Page last modified: Tue, 5 Aug 2014 22:18:23 +0200
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