The 'quick an dirty' serial cable with just 3 wires worked under various versions od MS DOS (3.30 - 6.0) on various hardware platforms (286 - P1).

For example, Telemate (DOS terminal program) worked like a charm and Kermit/XModem could be used for file transfer between two PCs. I've even used it to connect Atart ST and 386 once. Further, Borland Turbo Debugger's tools for remote debugging (tdrf and tdremote) could be used for file transfer as well. No probs there either. I've done it hundreds of times, and in the time before LAN became cheap solution and CD was not even hinted, I've often improvised 'ad-hoc' 3-wire cable in order to do file transfers between two PCs. So it sure works.

As for windows, I'm still using HP48SX scientific calculator, with hand made serial cable. Only 3 wires also, no hardware handshaking. It also works without problems.

So, I must back up Andy's assertion that you have application specific problem rather than hardware one. PC's comm port is indeed capable of running communication on 3 wire cable without anything else. Maybe your application or some library function along the communication chain simply makes faulty init of comm port requiring it to have hardware handshake.

There can be a weird hardware issue too, I've once seen an ISA rs232 card that had jumper selection for handshaking and there was little drivers could do in that case, though I doubt that you have this kind of problem, but who knows...

Best luck,
CN