#4 legacy code? might interfere with first comm port if using second.

[simon]

this looks like old code not tidied up;
rs232rctl line 51, a hard coded ref to "/dev/ttyS0"?

rs232_open (char const *device, int dbug)
{
tRS232 rs232;

rs232 = open ("/dev/ttyS0", O_RDWR | O_NOCTTY); <===== ??

if (dbug) printf ("%s ", device);
rs232 = open (device, O_RDWR | O_NOCTTY);