I don't have a
Classic, but I know that this Classic receiver seems to be strange and different from the earlier Fortec receivers, and I have been wrong before about the way things are done with the Classic. However I really have my doubts that a null modem cable is really needed. I don't doubt that it will work, if that's what the manual calls for, however if someone is trying to make their own cable, I wonder if all those wires are really needed, and perhaps a simple crossover cable might work, ie 2-3,3-2,5-5 ??
All those other wires are often needed if the software uses hardware handshaking, but that is getting more and more rare these days. Almost everything I've wired serial cables for in the last decade have not needed the hardware handshaking wires. I'm just curious whether anyone with a Classic has tried a 3-wire cable. The 3-wire cables work fine for my Lifetime and Ultra, and for several scanners, and other devices I've made cables for. Nice thing about the 3 wire approach is that you can use thin modular telephone line, and radio shack sells modular connectors for telephone wire that you can choose what pin goes where.
Anyway, I haven't seen a device that really needed a null-modem cable for years. Of course it wouldn't surprise me if it was the Classic that broke that string, because Fortec seems to have decided to re-invent the wheel with that receiver, instead of using what works and getting rid of what doesn't work, from past receivers.