Hello,
this is my first post to this forum. I hope so far, it is ok to you. I try to connect my pascal code to serial ports like /dev/ttyS0. If I use indeed /dev/ttyS0 ... S3, it works fine. But it seems, fpc doesn't understand serial ports like /dev/ttyS4 or /dev/ttyUSB0, and I cannot figure out, where the problem is. I intend to use the unit serial and hope so far to find someone, who knows, what can be done to get the code running as expected.
Best wishes, Holger