SlackBuildsOrg/system/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.