On a sunny day (Sat, 19 May 2018 18:54:26 GMT) it happened Jan Panteltje
 wrote in :

>I was thinking if I was in the boonies and had no other option
>and HAD to use the non inverting cable and IF it did not blow up on real RS232
signals on its input,
>then MAYBE I would xor ptlrc output bytes with 0xff and same for input bytes
to force the invert ;-)

Actually that won't work, as you also need to flip start and stop bits, not
just the data.
One could write a software UART (done it) but that won't work in Linux due to
the taskswitch interrupt.
You need a real USB to RS232 adaptor.

--- SoupGate-Win32 v1.05