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.

For your convenience you can find the manual page here. If after reading it you have a question, please next 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:

28/07/2020-Release of version 2.3.6
Not much of an interesting release. A small potential buffer overflow and some spelling errors fixed. The FAQ updated and that is mainly it. A bit boring, but here it is: version 2.3.6.
Might be nice to add though that after a couple of decades after industry standards this software is also finally digitaly signed. It's about time! Kuddo's to Debian for nagging me about it.

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.."...



Please see for the latest and greatest version of the source code.


The current release of jpnevulator is version 2.3.6, which was released on July 28th, 2020. Download this compressed tarball(35.2K) and see the README and INSTALL file for more information on how to compile the program.
Please use my public key together with this signature to verify the authenticity of this release.

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
Please see if you want to create your own Debian package out of this software.


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

Page last modified: Tue, 28 Jul 2020 13:26:42 +0000
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