What I'm saying is that, since I don't know what the application is doing with the handshake or lack thereof, I've found that using the cable with the tiebacks works whether the application handles the data flow control in either hardware or software, and, since the application seldom tells me what it's doing, I use what works. The tiebacks have never interfered with normal operation. That doesn't mean they were essential, but only that they didn't cause the process to break down.

Doesn't it make sense to provide the three or four wires rather than to have to skull-out each and every application?

RE